Fixed it at last! Slow, low power, stalling.....

[davehuge]

My son's Taishan Commuter has been driving me nuts but I've fixed it at last.

Problem was..... it would start ok and rev ok on the stand. Set off up the road and it would loose power after about 100m and then stall.

I convinced myself it was a carb problem and stripped the carb a number of times, cleaned out and tried different float settings, but the problem remained the same. I also tested the autochoke unit and valve on the bottom of fuel tank.

In the end I removed the engine and removed the cylinder head. Only one bolt and the rear shock to unbolt and the whole engine/rear wheel comes out, neat.

I found that the exhaust valve wasn't sealing properly , I ground both valves in and rebuilt the engine.

Immediately I noticed that there was much more compression when I pressed the kickstart. I went for a ride on it and it runs perfect and tick over is much smoother.

It now sits at 40mph no problem, even with my fat butt (15 stone ) on it.

I think these little scooters are great value (just need to make sure they're set up ok ), ours cost £300 and it's only 6 months old and done 1000 miles.

See you all, Dave.

P.S. Great website too!

[Ginger Phil]

Cheers Dave!! ;D

As much as people slag off these scooters when they run right they run good.

[dcb1066]

hi , i have a taishan commuter and i have the same problem with losing power after 100m or so , you make it sound so easy to remove the engine . i don't think i should try this or is it easier than i think ? . great website lotsc of useful info . from darren

[Ginger Phil]

Glad you're enjoying it Darren.

[baotian]

Hi Dave, i have this problem (sometimes) when i open the thortle from stand still, it just stalls, can you tell me how to check these valves?

Thanks
Chris

[bridleman]

Chris
The simplist way to tell if the valves are seating ( ie; not letting compression escape) is to have a compression test with a guage that srews into your spark plug hole,Cranking over the engine then reading the pressure off the dial (Like reading your tyre pressuer) Or..,D.IY.

Step one.. When your engine is cold take out your spark plug, Place a fingure over the plug hole while cranking the engine over, There should be quite a 'Phutt' as the compression pressure tries to push your fingure off the hole.

If there seems very little or no pressure ... go to..

Step two.. spurt a small amount of oil (about a spoon ful) into the plug hole and once again cover the plug hole with your figure and crank over the engine.

If there is not a great difference in the feel of pressure it 'may be' that the valve gaps are to tight and the valves are not closing fully (gets worse when the engine is hot as metal expands with heat) Remedy.. WHEN ENGINE IS COLD... check with a feeler gauge and adjust... This being a routine maintainence job.

Or they are not seating. Remedy, Cylinder head off valves re- ground) Not an hard job, but better if supervised by someones who's been there,done that, got the tea shirt etc:

But ALWAYS go for any easy option first, It could simply be a duff plug.. change it,..Damp in the sparks department / leads coil /wireing,.. spray with WD40...Carb mixture not set up right,..etc.

Mike (Walsall)

[BillyGreen1973]

Good post. thanks

Have some Karma!

[baotian]

yes very good reply, have some more kamra! thanks alot for explaining this, i will have a go at this the weekend, but just to let you know i have already changed my spark plug to a NGK one, so that shouldnt be the problem.
is this normal to happen staight after deristricting?