Honda SGX50 Sky Specs and Info (1997 to 2003)

Honda scooter parts

Honda SGX50 Sky Parts…

Honda SGX50 Sky Specs

SGX50 Sky with chrome plating on the exhaust cover

Honda SGX50 Sky Specs…..

The Honda SGX 50 Sky was a budget, step through, 2 stroke, 49cc scooter/moped hybrid with 16 inch wheels sold in the UK March 1997 and May 2003.
The SGX50 Sky was available in 3 different styles, a basic model, a ‘Deluxe’ model with chrome plating on the headlight, tail light, indicators and rear carrier rack and a ‘Fun’ model with semi transparent bodywork.

Although the SGX50 Sky was popular for a short while in the UK, it proved very popular in Southern Europe because of it’s simple styling and ‘easy to use’ features.

The SGX 50 was, at one point, considered as a likely replacement for the Honda C90 Cub.

Working on your bike? You’ll need a SGX 50 workshop manual…

Basic model info…

Manufacturer: Honda
Model: SGX50
CC: 49cc
Engine type: Single cylinder (2 stroke)
Years in production: 1997 to 2003
Style of bike: Scooter
Insurance: Group 3 (of 17 – estimated) – Expecting your insurance to go up this year? Get a discount at
SGX50 Sky parcel shelf

SGX50 Sky rear carrier rack / parcel shelf

A little bit about the Honda SGX 50 Sky…..

Models and years (in the UK)

SGX50-V Sky (March 1997 to Dec 1997)…..
Description: Budget step through moped with 16 inch, cast alloy wheels, moulded bodywork, rear carrier rack and dual seat.
Available colours: Black, blue/orange or red
Cost new: £1095
SGX50-V Sky (Jan 1998 to Oct 1998)…..
Description: Same as above model with different colours.
Available colours: Blue/orange, red/black, black/yellow or brown
Cost new: £1095
SGX50-X Sky (Nov 1998 to March 2001)…..
Description: Same as above models with different colours.
Cost new: £1095
SGX50-Y Sky (April 2001 to June 2003)…..
Description: Same as above models.
Cost new: £1095
Other SGX50 Sky models…..
SGX50 Sky Deluxe: Deluxe version features chrome-plated parts such as headlight, taillight, indicators and carrier rack.
SGX50 Sky Fun: Fun version features excit-ing new ‘transparent’ colour bodywork.
SGX50 Sky engine

SGX50 Sky single cylinder, 49cc, 2 stroke engine

Engine and gearbox stuff…..

Displacement: 49 cc
Engine type: Single cylinder (2 stroke)
Bore×Stroke: 39×41.4mm
Compression Ratio: 7:1
Cooling system: Air cooled
Clutch: V-Matic
Gearbox: Automatic
Gearbox oil: Separate gearbox oil (10w40 gear oil)
Max. Power Output: 2.5 BHP (@ 6,500rpm)
Max. Torque: 3 NM (@ 5,500rpm)
0-62 mph time: For bloody ever!!!
Top speed (approx): Slightly faster then walking?
Idle speed: 1800rpm
Final drive: CVT (constantly variable transmission) belt drive
SGX50 Sky Exhaust

SGX50 Sky genuine Honda exhaust

Carb, fuel and oil stuff…..

Fuel system: Carburetor
Carb type: 1 x Keihin 12mm piston-valve type
Carb type: PHVA12
Fuel type: Unleaded petrol
Lubrication: 2 Stroke oil
Gearbox oil type: 10w40 Motorcycle oil
SGX50 Sky starter solenoid

SGX50 Sky starter motor relay (part no: RC2208)

Electric stuff…..

Ignition type: Electric CDI
Starter: Electric start and kick start
Electrical system voltage: 12 volts
System voltage: 14 to 15 volts (@ 5000rpm)
Spark plug: 1 x NGK BR6HSA
Spark plug gap: 0.6 to 0.7mm
Spark plug tightening torque: 14nm
Spark plug ignition: 1 x Coil (built into the CDI)
Magneto/flywheel tightening torque: 40nm
Battery: YTX4L-BS / CTX4L-BS
SGX50 Sky wheels

SGX50 Sky 16 inch cast alloy wheels

Shocks, brakes and wheels stuff…..

Front wheel type: 3 Spoke cast alloy wheel
Front tyre size: 250-16 (tubed – Same as 2.50-16)
Rear wheel type: 3 Spoke cast alloy wheel
Rear tyre size: 275-16 (tubed – Same as 2.75-16)
Front wheel spindle torque: 44nm
Rear wheel nut torque: 118nm
Front tyre pressure: 25psi
Rear tyre pressure: 32psi
Front brake: Single disc brake with 1 pot caliper
Front brake disc: Disc brake MD931D (EBC)
Front brake pad: EBC SFA193
Rear brake: Drum brake
Rear brake pads: EBC H303
Front Suspension: Telescopic grease-damper fork
Stanchion diameter: 27.2mm
Front suspension travel: 70mm
Rear Suspension: Single monoshock
Rear suspension travel: 80mm
SGX50 Sky cylinder

SGX50 Sky 49cc engine cylinder barrel

Weights, measures ‘n stuff…..

Length (wheelbase): 1,230mm
Seat height: 775mm
Width: 665mm
Ground clearance: 135mm
Dry weight (no oils, fluids etc): 71kg
Fuel tank capacity: 4.5 litres
SGX50 Sky basic model

Basic SGX50 Sky model in red

Service stuff…..

Gearbox / final drive
Check oil: Every 4000km (2485 miles) or 6 months
Change oil: Every 24 months
Gearbox / final drive oil: 10w40 Motorcycle oil
Hydraulic brake system
Check brake fluid: Every 4000km (2485 miles) or 6 months
Change brake fluid: Every 24 months
Brake fluid: DOT 4 motorbike brake fluid
SGX50 Sky under seat view

SGX50 Sky view under the seat with battery, 2 stroke and petrol caps and identification sticker

Frame number location…..

The frame number information plate can normally be found on the main frame beam behind the front wheel (on the right hand side as your sitting on the bike).

SGX 50 clock

Honda SGX 50 Sky clock

Useless stuff…..

Very cheap, cheerful and basic moped and parts are fairly easy to source and cheap.
The SGX50 Sky was, a 1 time, likely to be the successor to Honda’s massively popular C90 Cub, but unfortunately it fell short of the mark.
The SGX 50 was alot more popular in warmer European countries then it was in the UK.

Buying advice…..

The Honda SGX50 Sky was a fairly reliable and cheap 2nd hand bike. Larger front wheels make it popular with learner riders.
Things to check are:
Exhausts (as the originals are mild steel, which rots. Pattern replacements are around £70).
Automatic choke: The auto choke is attached to the top of the carb and can be problematic as they age.
Forks: As there not easy to get hold of in good condition 2nd hand

The SGX50 was popular as a food delivery bike in many cities (Pizza, Kebabs etc) and these generally will have been used and abused so are best avoided (you can usually tell the delivery bikes as they often have a modified seat and larger carry rack on the back).

There were some ‘special edition’ models of the Honda SGX 50 Sky, but these only had a few modest visual changes and aren’t really worth anymore then the standard models.

360 Degree view of a 2001 Honda SGX50 Sky…
SGX50 Sky 360 view 1
SGX50 Sky 360 view 2
SGX50 Sky 360 view 3
SGX50 Sky 360 view 4
SGX50 Sky 360 view 5
SGX50 Sky 360 view 6
SGX50 Sky 360 view 7

Sources / Thanks to:

Honda Owners Club UK – Who have a handy SGX50 sale brochure you can download from their site.

Honda SGX50 Sky Spares…

Disclaimer: The information on this page is correct to the best of our knowledge. But the info should NOT be taken as 100% accurate as we can, occasionally make mistakes!


86 responses to “Honda SGX50 Sky Specs and Info (1997 to 2003)”

  1. hi have daughter with a honda sky 2002 but the engine want fire up. batt charged .fuel to carb spark at plug , but the fuel is spat out when force fed . please can you help, ladies in destress.? PS does it have a saftey cut out as she went down a pot hole and it would not start after that.

    1. There’s no cut out on the Honda SGX50, more then likely something was dislodged or blocked when the bike went down the pot hole? Where is the fuel coming out from? Hope your daughters ok BTW?

    2. The problem you have is the crank seal they around 2 pounds to but I had same problem after changing it fired up fist time

  2. I am using a honda sky in Ghana
    its second hand and was really giving me problems. doesnt start. Had mechanics fiddle with it but I noticed that when I started using car engine oil and sparked it while still up on the stand it would work
    I was told to use very light oil so I ppured some dot 4 brake fluid into the engine. I think the bike os picky about its oil.

    1. If your using car engine oil instead of 2 stroke oil your probably fouling the spark plug?
      You need to use a 2 stroke oil in a 2 stroke bike (and a 4 stroke oil in a 4 stroke bike).

    2. derek stephenson Avatar
      derek stephenson

      you do not putbrake floud in a engine

  3. Denholm Colchester Avatar
    Denholm Colchester

    I have had my Honda sky for a few years now and now im old enough am wanting to derestrict it how would I do this??
    Also what is the fuel consumption on these actually like??

    1. I’m not exactly sure how the SGX50 Sky is restricted, but you could try the following to increase the BHP:

      • Sports exhaust
      • Better/performance variator rollers
      • Fitting a performance variator kit
      • Cone style / performance air filter (instead of the airbox)
      • Fitting an oversized pulley
      • The bike may be restricted by the CDI, if you could source a non UK CDI this might help (or look into getting the CDI derestricted)?

      Opinion varies based on different user experiences with the SGX50 Sky, but you should be getting around 100+ mpg out of it?

  4. Hi, hope you can help. I have an 2002 SGX 50 Sky Honda. It starts and runs well but I have now lost electric start, indicators, horn, and brake lights. Lights are working ok and the battery is good as is the fuse next to the battery. Are there any other fuses.? Thank you in advance. Mel.

    1. I think there’s only the 1 fuse near the battery (but, if there are any more they are probably under the battery cover panel?).
      You may have a bad earth connection on the bike. If you can see any wires that connect directly to the frame or engine, check there not excessively dirty or broken?

      1. Many thanks for your response, will try this at the weekend. Kind regards, Mel.

      2. Rihard Avatar

        and a low fuel warning as well, honda was a bit dumb with that, left me without fuel last friday 😀

        1. There should be a low fuel warning light on the clock (just below the 2 stroke warning light)?

          1. Rihard Avatar

            Hi, where can I find the starter relay on a bike ?

          2. should be on the back of the bike (on the metal tail panel). It’s a small, black, oblong shaped relay in a black rubber case. The relay will have the part no: RC2208 marked on it.

  5. Hello guys, i just bougth an Honda sgx 50 and i want to ask you 3 things:
    Is it normal to do just 80 km with 4 l of petrol?
    The normal start doesn t work, what mitgh be the problem?
    The kick start has a low compression, it could be a problem?
    Thanks in advance, txau

    1. Hello 🙂
      You should be getting over 100 mpg (miles per gallon) from the bike, so 80km from 4 litres isn’t good?

      By normal start do you mean the electric start (the switch on the handle bar)? If yes it could be a bad connection or faulty starter motor?

      Re the kick start low compression, does the bike actually run and is there good compression in the cylinder?

  6. Peter Avatar

    Where I can find indicator relay anyone can help?
    Thanks in advance

    1. There seems to be loads of places selling them online (link below)?

    2. minisareus Avatar

      in front panel behind sky logo

  7. stephen mew Avatar
    stephen mew

    hi there wondering if you can help ,bought a fx650 49cc was in pieces now slowly back together finally got it working but got told had to put some oil in the crank case how much oil is needed to go in?



    1. Sorry, do you mean you bought an SFX50?
      Honda FX650 is a big, 650cc trail type thing?

  8. Jon Mortimer Avatar
    Jon Mortimer

    Motorcycle. Just wrote that in case! Hi there

    You being one of only a very few with any online info on the Sky I hoped you may be able to advice……I’ve just had the crank case oil seal replaced as it had split and led to crazy revving when throttle was closed (been told as it would have allowed air in.) Had it all put back together, seemingly ok except there is now a minor-moderate vibration coming through which you can feel at all points of contact and on every belt revolution there seems to be very minor drag/friction equal to the non drag ie half the time. Took the casing back off and belt looks fine so it must be further into the crank where the front plates came off – which you need the special tool for that I myself don’t have. Before I take it to another garage (as mechanic i used abroad for a month) have you any suggestions please? Much appreciated


    1. Could possibly be a bearing on it’s way out?
      Whats the mileage and age of your scooter?

      1. Jon Mortimer Avatar
        Jon Mortimer

        Its an X reg and has done 9500 miles. If it is a bearing what is involved with that – sounds like a big job? The thing is though there was no vibration at all before the crank oil seal was replaced…..could it be the plates of the crank have been put back either slightly in the wrong position or too tightly or is there only one way they can go back? It looked on the engine diagram like there was one missing altogether although the dealer told me that British models didn’t have a derestriction plate and they were certain this is what we were missing and it was never there. Does this sound likely? I’ve heard the rollers can go on these bikes in the crank but I don’t even know what they are…..Thanks for the replies anyway – I will find the gear oil input I’m sure – assume its additional to the oil for the engine you put in next to the petrol tank. (I’m not being that dumb surely?!)

        1. Yes, the gearbox oil is in addition to the engine oil, so does need to be drained and filled separately.
          It does depend which bearing is failing, any bearings around the crank will need the engine to be striped and rebuilt (you would need someone experienced to show/help you with this).
          To be honest I don’t know about the de-restriction, but UK bikes are generally restricted to comply with scooter horsepower and speed restrictions.

          There could be a washer or similar missing from the clutch, but the vibration is more then likely to be a failing bearing (please bear in mind it’s difficult to diagnose faults over the internet though!)

  9. Jon Mortimer Avatar
    Jon Mortimer

    Also I am maybe being dumb but I can’t see where you put the gearbox oil in?

    1. I think there’s a little plug on the end of the engine casing where the rear wheel bolts to the engine (haven’t got a complete engine so can’t check unfortunately). You will probably need a small funnel to fill it though.

  10. Hi, on a 12mm carb with electric/automatic choke, where does the pipe go to? My bike never had one fitted and I agree, there is an insufficient amount of real, tangible advice for these bikes, thankyou.

    1. There should be 2 pipes, 1’s the inlet for the petrol and the other is a drain hose that goes from the bottom of the float bowl (it doesn’t connect to anything, it’s just there for the fuel to drain from the float bowl if needed).

      1. Thanks I know what you are explaining but I was on about automatic choke 12mm carb. At the top of carb you have petrol coming in but next to it is another one, is this a breather or vacuum and where does it connect to? Thanks for the speedy reply.

        1. I think there should be 2 hoses coming from the fuel tap on the tank, the 2 connection points on the carb might be for the fuel (main jet and pilot jet)?

          Not too sure to be honest as am trying to work from memory!

  11. Im looking for the indicator relay. Not to buy it but where the place is they set it.

    1. I’m not to sure where it goes to be honest, it’s normally a small, black block with 2 spade connectors coming out of it. If you follow the wires back from the indicators you should find it.

    2. Wilderness24 Avatar

      Unscrew the little screw at the bottom of the headlamp and open up. The indicator relay is inside the headlamp casing,

  12. I have one for five years, any problems except leaking oil tank-it has to be changed but im lazy about it. Just bought 2 used other Sky from England. Seems to be a bit work done around , needs to shange the variator, because it is factory made to go not much than 45-50 km/h and therefore the variator belt does not go to the deep position. No other problem. very fine bike for town, fields and forests, I ride my Honda when I go fishing

  13. Tony Richards Avatar
    Tony Richards

    Hi, I drained the float bowl after leaving the scooter parked for a year and now it will not fill up. is there an electric fuel switch or something like that, plenty of good fuel in the tank just not in the carb!

    1. Sounds more like a blockage or air lock in the fuel pipe going into or out of the fuel tap (or a faulty fuel tap)?

  14. Hi.

    Just wondering if you know where the CDI is located on the Honda Sky?


    1. Follow the thick, black (HT) lead back from the top of the spark plug and you’ll find it’s connected to a black box, this is the CDI/coil pack.

  15. Ivà Guillaumet Avatar
    Ivà Guillaumet

    Hi, I own a Honda SGX 50 Sky built in 1998.
    My problem is that I can start de bike but once it is on, after few seconds, begins to accelarate till the maximum. Moving tha gas cable, does not makes any difference.
    I have to turn off the key to stop it.
    Also, while doing so, the noise of the engine is very loud, like if the exhaust had a damaged silencer.
    So, I checked the joints between the carburator and the engine, everything looks fine.
    It is possible that a dirty carburator, could make the bike to accelarate like that?
    I changed the gas cable because was a bit scratched, but it was working properly and it was not getting stucked.
    Has anybody experienced such a problem? my next step will be to clean the carburator, but I do not know if a dirty pipe or screw, can cause such a behaviour in a bike.
    By the way, the vehicle has been working just fine, till some day, the noise got louder and I could not start it for some time. Now, it starts but i accelarates by itself.

    1. I have this accelerating problem in the past, it’s normally due to the accelerator cable being routed incorrectly if you’ve changed the cable (basically if it’s routed the wrong way this causes the cable to ‘stretch’ and open the carb).

      If the cable is defiantly, 100% routed correctly, it could be a dirty/pitted or worn carb needle or a blocked carb jet?

  16. pierre bijnen from holland Avatar
    pierre bijnen from holland

    Hello, i’ll try in english. my honda sky engine does fail, sometimes during driving, sometimes when i want to start is. after a while the engine starts again and rides perfect but than its stops again. When the engine works, its possible to ride for a long time, so i think the problem is not the fuel.
    i looked for the bobine. its a Ducati-energia with the cable for the sparkplug en four little pins.

    do you perhaps have any idea what the problem is. I thank you. Pierre

    1. If you’ve got a problem, there are 3 things to check:

      1) Fuel – Make sure the fuel in the bike is clean, not to old and that none of the fuel or air lines are trapped or damaged.

      2) Compression – Ideally, you should use an engine compression tester, but, you can check this by removing the spark plug, putting your thumb over the plug hole and starting the bike to feel if there’s good pressure (if your not sure what good pressure feels like, ask an experienced friend to help you).

      3) Spark – Is the plug old and dirty (especially with 2 strokes, if there’s an engine problem change the plug for a new one so you can rule out a problem with the plug)? Is there a fault with the HT lead (the lead that comes off the spark plug cap) and is the CDI / Coil pack working properly (this is the box the HT lead connects to).

      For your bike I would try changing the spark plug 1st (replace it with a brand new one), if you still have the problem, check the HT lead and coil pack.

      Hope this helps.

  17. Alexander Avatar

    My throttle cable keeps hanging so it will only speed up or rev the engine at full speed any thougt what it might be???

    1. Normally it’s caused by a sticking cable or by the cable being routed incorrectly through the bikes frame?

      Have a look with the scooter on full turn to see if the cable is getting caught on something to excessively stretched.

  18. Terry Mc Neela Avatar
    Terry Mc Neela

    Hi I have a 1999 sky that I have had for the last 16 years I works perfectly for my needs but of late the auto choke seems to take a long time to kick in and reaches high revs when starting up. Can you tell me what the cost of a replacement is and how do I go about fixing it. Regards Terry.

    1. New chokes seem to go for around £15 (I wouldn’t personally bother getting a 2nd hand one as you don’t know how long it will last!):

      SGX50 Auto choke on Amazon…

      You will probably need to remove some of the panels to get access to the carb, the auto choke is the tubular black plastic bit near the top/side of the carb.

  19. Bryan Delanchy Avatar
    Bryan Delanchy

    Hi. My son’s sky won’t start, good spark but does not seem to be getting any fuel. He ran out and when he refilled it turns over but no start. Is there a fuel pump which might have gone or some other way of cutting off the fuel? Took the fuel hose of from underneath the tank and it was dry. Thanks

    1. There’s no mechanical fuel pump, I think there is a vacuum pump on the bottom of the tank though (follow the hose back to the bottom of the tank, you should find it), it might have an air blockage in it?

  20. I’m getting a Sky in the next week. It needs the crank seals doing. I assume I’ll need to take the ignition off to get to them. Has anyone got a link to a how to guide?

    Never timed a 2 stroke before.

  21. hi i bought a honda sky 1999 for a runaround it starts and runs fine but the rest of the lights and horn etc do not work i can only see 1 fuse at at the battery its fine and i will try the earth wire , dose the ignition switch have anything to do with it ,thanks in advance for your help.Tom

    1. I think the ignition switch controls all the power, so if it didn’t work the bike wouldn’t start.

      You could try checking the wires back from the ignition switch though, looking for any damage.
      Or check the handle bar control and wiring from it for damage?

  22. thanks got the lights working it was the bulbs
    the next problem is the center stand when it is up on stand the stand is resting on the box section frame steel to steel and is overstretch the spring should there be a rubber stop somewhere as it has none thanks

    1. I think there should be a stop on the exhaust for the center stand?

      1. hi the top speed i am getting out of this scooter is 30mph is there a variator or other make out there tom give more speed as i don’t like giving the bike full throttle thanks in advance tom.

        1. I’m not sure how the power and speed is restricted on the SGX50?

  23. Terry McNeela Avatar
    Terry McNeela

    I have a 1999 sky had it for 17 years only use it for shopping hence 5,500 mi les but having bad knees it is my lifeline. Recently the engine has been cutting out when I increase the throttle but picks up when I decrease the throttle. This fault is intermittent but it is getting more and more regular. I know it sounds like a blocked main jet but could it be anything else, This has only happened since I filled up last time. Could it be bad fuel (condensation from petrol station)? I cant think of anything else, I would be very grateful for your take on this. Regards Terry.

    1. Do you mean the revs increase when you decrease the throttle (so it’s working in reverse)?
      If it’s cutting out as you increase the revs it could be a blocked pipe (check no air/fuel lines have been moved or damaged), check the seal around the carb manifold and air intake (also the manifold, where the carb connects to the engine) if it’s a rubber one.

      Failing that, it could be a carb in need of a good service and clean.

      It could be bad fuel, but I would say unlikely as normally with bad fuel the vehicle won’t run or will run bad all the time.

  24. Terry McNeela Avatar
    Terry McNeela

    Further to the above comment if I disconnect the fuel line from the tank will the fuel run out, I cant see a petrol tap ?. I don’t know how to clean jets, never done it before. there is a Honda dealer near me but they seem only interested in selling bikes. Any thoughts on that ?. regards Terry.

    1. There is a vacuum pump on the bottom of the tank, it shouldn’t draw fuel out when disconnected (it shouldn’t but it might however!).

      There’s loads of videos about carb cleaning on Youtube which might help:

      Larger dealers are unlikely to help, you might have to do it yourself or find a smaller garage/workshop who can help you out.

  25. Terry McNeela Avatar
    Terry McNeela

    Hi, I think I confused you with the last comment. On full throttle the scooter runs flat out, but when I shut off and then run at half throttle that’s when it cuts out which is quite dangerous in heavy traffic. After a while it picks up again but the damage is done by then. Ive just had a new plug put in but that hasn’t done the trick I’m getting rather desperate now, The last bill for checking it out was £97 with no result.

    1. If your having trouble with the mid range and idle it could be a worn or pitted needle and/or a blocked pilot jet (the needle might be a good place to start).

      Unfortunately, you are probably going to have to strip the carb to find out for sure.

      You can view a diagram of the carb and get some parts on the site below (I’ve never used them so don’t know if there any good?):

  26. J.D.W Avatar

    How much gearbox oil do i have to put in when i renew it? Kind regards

    1. You should need about 100ml of oil for the gearbox.

  27. Hello,

    Maybe that is a strange question but: is the Honda SGX sky 50 for 2 people or only for one? I can’t find anything about that!

    Thank you!

  28. Hi,

    The low fuel warning light doesn’t work on our Honda Sky SGX 2000 make. Do we need to replace the bulb..if so, how can we do that?
    Thank you.

    1. You can replace the bulb, you’d need to remove the clock from the bike and they remove the lower casing to get access to the bulbs.
      But, these bulbs don’t very often fail, so the problem may be with the fuel level sender unit in the petrol tank?

      1. Many thanks, I’ll have a go in replacing the bulb myself, but if the problem is down with the level sender unit, I might ask a specialist…but so far(after breaking down with no fuel once), I am keeping an eye on the the miles clock and top it up every 50 miles.

  29. Avatar

    Hiy my honda sgx50 sky has stopped working.. Got spark and fuel and wont fire up?? Help please thanks

    1. Might be a fuel blockage (blocked/damaged pipe or faulty vacuum pump)?

  30. Frank Aspinall Avatar
    Frank Aspinall

    Hi, my Honda Ventro SGX50Y blows the 15A fuse as soon as I turn the ignition on, I cant find an obvious fault. Any ideas would be very welcome.

    1. Probably a loose or damaged wire, check any areas where the wires move or rub (especially around the handle bars and head stock). If the wires are intact you could try removing clipped on electric components to see if this stops the fuse blowing?

  31. Hi all, just taken delivery of a ’97 SGX50 in reasonable condition. BUT it’s a non-runner 🙁 Gets a good spark and has good compression. Only 4000 miles on the clock. My suspicions are taht it’s something to do with the auto choke? I’ve got a load of old brit bikes from the 50s n 60s where everything is manual and easily fixed. These sealed units befuddle me as they’re so tough to diagnose. As I say the engine turns over fine, shows a good steady spark but will not draw fuel into the combustion chamber. Checked the reed valves – all seems fine. Replaced the vacuum petcock – no improvement. After turning over the plug is still dry…. One other thing is that the engine won’t turn over on the start button. I have to run power direct from the battery to the starter relay. Can’t find a wiring diagram anywhere. The alternative diagrams seem to miss a few components. I’ve tried getting the auto choke to activate by connecting power across the two wires – nada. The little needle does push in and sring out by finger pressure. I have poured fuel down the plug hole and it still won’t start. Tried filling the float chamber and it won’t fire. Poured fuel down the manifold and it won’t fire. So……. does the auto choke cut out the fuel supply? Is there a fuel vacuum issue? Does the fact that the starter switch doesnt work have some bearing? Could someone perhaps give a basic description of how this fuel system works ? Any and all help very gratefully received 🙂

    1. It does sound like a fuel blockage somewhere or possibly an air lock in the vacuum pump?

      1. STEWART men PORTER Avatar
        STEWART men PORTER

        Thanks for getting back to me. I’ve fitted a new reed valve – no difference. Stripped out the oil pump as that seems to control some of the vacuum in the inlet manifold – it seemed ok and was all refitted tight – no difference. I’ts a mystery! Took off teh head and barrel – everything ok there. It’s only got 4500 on the clock. I’ve ordered new crank seals. As it hasn’t ran for a while and lain unused, perhaps there’s a compression issue but it seems alright by “finger-testing” it off the spark plug hole. I don’t have any info on what the compression numbers should be, so have nothing to compare it with. I replaced the fuel cock, so that should be ok. All I suppose I can do is strip it out, fit new seals, check all I can in the process and hope for the best 🙂
        Will keep you updated

        1. The problem is likely to be with the fuel not getting through (hence the dry spark plug). You might need to check that any fuel pipes are not kinked or damage and that any breather pipes are also undamaged.
          Also check that the pipes are routed correctly and not getting caught or squashed (for example when the seat is put down).


    Thanks dog, Yes , have checked, cleaned, cleared all pipes several times now. All good. Just doesn’t seem to be drawing fuel from float bowl to barrel. All jets etc been cleaned and checked too. Can only imagine that there’s a lack of suck in the barrel due to dry old seals but I’m thinking that’s even a long shot. Got a flywheel puller and waiting for new seals, so strip down on the cards. Probably be the usual story – strip it down, find nothing wrong, build it back up and it’ll go like the clappers!! 🙂
    Keep you posted

  33. Ryan24 Avatar

    Where would I go to get parts for a Honda sky 1999?? I got one its bare metal used for a field bike wondering if theres any point in restoring it??

  34. Hi I have a Honda Sgx50
    Im having problems with starting her she was running fine now won’t start iv put a new spark plug but that still ant working I’m trying to get a cdi for it and can’t get the part someone help me

  35. Michael Chatwin Avatar
    Michael Chatwin

    Hi, I’m having trouble with my 1998 Honda sky, it’s only done 6k miles so it’s barely been ridden. It starts and runs fine, but after a little while on the road starts to judder a little and then bog down wont rev. It doesn’t cut out at this point, you just have to pull over and let it idle for a few seconds and then it’s good to go again. I have just changed the spark plug battery and air filter so it’s not any of those.
    I’ve been told it could be something to do with the variator? Rollers not advancing or contracting correctly? Just wanted to see if anyone can shed any light on the problem.

  36. Denis from Baltic sea Avatar
    Denis from Baltic sea

    I have been using Sky for two years, a great bike, it has only two problems. 1 – crankshaft oil seal. The original one from production fails very quickly. Now sold in Japan for this model they are already selling an increased diameter of the bore by 1 mm, they solve the problem for a long time. Signs of this, the revs increase greatly, without twisting the accelerator. Difficult to start, and oil from the bottom of the engine cover, you need to remove the cover. 2 – switch ducati energy, rotate contacts, may simply stall on the way. Exactly the same ones can be bought in Taiwan. From suzuki katana 1 in 1 is suitable. The engine is the same as on the Honda X8R and Honda Lead 50 2T. Lead has less leg length for the wheel, the rest is the same. To increase the speed, I used a set of mallossi variat 517117. And you can buy a malossi ventilator 617377, this is the external CVT cheek, but my speed increased to 65-70 km / h without a ventilator. When installing it, you do not need to put a plastic ring (speed limiter, which is included due to the law).
    Sorry for bad English)
    I hope my information will help everyone who still rides this wonderful motorcycle!

    1. Denis from Baltic sea Avatar
      Denis from Baltic sea

      …I forgot to write. It’s called Via in Japan.

  37. Saad Muhammad Avatar
    Saad Muhammad

    Hello I have Sky honda Bike 2000 model and i have a problem that the bike starts but it is not accelerating and picking up the speed. Mechanic has cleaned the Carburator and even the gas kit also but still now the bike is not picking up the pace? Is there problem in the CDI part which is for ignition or any problem in the Gas kit?

    Kindly reply


  38. Looking to find where the gear oil goes in my Honda sgx50 and how much goes in thanks

    1. There should be a filler bolt on the top/back of the motor. A good 10w40 motorcycle oil should be ok for it.
      Unfortunately, I haven’t got any accurate info for the amount but there’s a few references online saying it takes about 100ml of oil.

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