Lenght of Variator boss/slip ring req

[kevkeo]

Hiy everybody. Help needed. I have bought a xinling (2006). It has the usual engine, XL50QT-B. However it seems the manufacturers are getting a bit tricky with the restricting. There is only one boss/slip ring in the variator, and it looks longer than the ones shown in the dereistriction photos - courtesy of Billy Green. Could anyone tell me the length of a derestricted one, I intend to cut it down to size with a spacer washer waiting in the wings(as a filler) should it go wrong. Ive also replaced the jet for a 4mm 90, but the carburettor jet needle is a one piece moulded affair with a set needle cap(imagine a enlarged drawing pin and you've got it), no adjustments possible. Based on the fact that the cap is set higher to keep the needle low in the jet I thought I might try using something to imitate the removable circlip washer but I need an accurate length from the tip of the needle to the washer when placed on the middle groove. Alternatively, my carb looks identical to the one in aforementioned photos, could someone tell me what type/model the carb is and I'll try and locate a seller for a new needle. Many thanks to anyone who can help.

[cb50j]

the derestriction doesn't show the actual variator drive boss(like this)

what it means is, if you find one of these

remove it

www.asiamotor.se/eng

do the pin

..... C

[kevkeo]

I appreciate your answer, but is it possible that the manufacturers have incorporated the extra removable washer into a single piece boss to make derestriction harder. I feel that the variator is strugling to meet engine revs with equivelant output. If you know categorically that this is not the case I am happy to look somewhere else for the lack in output.

[blubayou]

cb50j is spot on as usual.

If however you do want to turn the drive boss down to give slightly higher gearing, 36mm is as short as you can realistically go. Mine is also fitted with a 1.2 mm spacer behind, otherwise the kickstart doesn't work. I'm running a big bore tho' & seem to remember 37mm is the ideal for 50cc, try it & see.

Regarding the carb needle, it should be fine as it is, I'm using an 0.85 on a more the less standard filter setup & that is rich enough, you may finf 0.90 too rich.

Let us know how you get on.

[enu06]

It could be your engine is struggling to meet the variator, these engines dont seem to make full power until they have covered a few kms, in the region of 750.

[kevkeo]

Thanks for all your replys, cb50j was indeed spot on, the boss is 37mm an my bike, and there is no restrictor. It moves freely the operational length. I tried an enlarged jet 0.96, instead of raising the needle and you were right blubayou. It created a flat spot which I believe due to to rich as you said, now back on .90. Very similar carbs to the old mini su's. These xinlings are definetely restricted somehow. 5 wires on cdi, no ring in the exhaust, no boss restriction, removed air filter for freeflow, and removed exhaust reverberator. I am going to try a new cdi next despite 5 wires(no pink). Any suggestions welcome. And cheers enu, but ive covered 1600k. Does anyone know who makes the engine, someone suggested them being a honda C6Y.?

[Jenkos0wls]

Hi these engines are Copies of the honda GY6 but the honda version is usually 150cc not 50cc and these companies bought the rights to make it andn call it 138 QMb something daft like that any ways heres a site that modified there 150cc go kart engine same thing can be applied to the 50cc www.rc-trucks.org/gy6-engine-performance.htm