Does anybody know of a decent engine for the thumpstar pro, i have just blown 2nd gear, engine is blowing blue smoke, and is pumping oil out the overflow, is there a kit or a way of strengthening the engine/gearbox. These bikes are doin my head in! 
Thumpstar engines:(
- Thread starter fecksfx
- Start date
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gazza2003au
Well-Known Member
probably the crank case oil seal has blown your gearbox oil will be entering the cylinder causing the blue smoke check the spark plug to see if u have black carbon deposits on the plug tip what is wrong with 2nd gear?
gazza2003au said:
It is just like neutral
I haven't opened it up, but it seems like it sheared off all the teeth on 2nd gear. I don't know how it works in there. If it only shore off a roll pin or something easily replacable I'll be a bit happier.Are these gboxs prone to doing this? It's not like it got powershifted without the clutch. I just bounced thru a rut in 2nd and it gave up. Maybe it just gets more traction than it can handle with the big wheel.
gazza2003au
Well-Known Member
check that the gear selector is changing the gears properly alot of bikes have had this problem and it turns out to be the selector not properly changing gears it gets stuck up do u have all other gears? if the gear teeth snapped off and u rode the bike without 2nd it would have seized the gearbox by now but could possable have snapped the whole gearing in two peices but my guess would be the gear selector u might need to split the cases if u didnt hear any metal flying around in the case just before u turned the bike off u should be ok
gazza2003au
Well-Known Member
if you bought the bike from this guy than take it back tell him what happen make it clear your not happy if he doesnt care than he only wants your $$$ and doesnt care about the product he is selling ask him for a complete print out of the motor so u know how it all goes back together also ask the dealer u got the bike from if he is willing to do a few hard parts for you free of charge (split case with special tool etc...) of corse after u have removed all the other parts :wink: one weekends work u should be back on the track if he helps u out and has parts in stock
No-Fear said:
The whole bike is an 06, will talk to dealer tomorrow, he has been great so far but i can see im wearing out my welcome. I am worried now that the other 110 that i have will suffer the same fate. The 110 is alot lower geared and i am gonna gear my 125 the same if i can. Thinking that this will help the lifespan of the engine.
I had ideas of doing some engine work to give more power but now really dont think it would be a good idea.
No Fear, how much difference do the harder springs make.
RD RACING
Well-Known Member
the main problem is, these bikes are chinese and cheap, you can,t expect to have a reliable bike with no sufferage to any components unless you pay the big dollars for japanese produced bikes.
fecksfx said:
They are sweet, with the rebound adjust working aswell i paid $160 for the new springs fitted and everything.
My mate paid $500 to have his forks re-drilled and everything, mine work just as good as his.
does ur pro have the USD forks or normal forks?
RD RACING
Well-Known Member
can you tell us where these pro bikes are made?No-Fear said:
yer with compresion and rebound ajustment, is sweet but you just gotta lube forks to stop them sticking to the seals. Have you done anything with your gearing, i reakon they are way overgeared. Have you had a ride on a 110? They are way lower geared due to the 10'' wheel, but haul ass 100% better on slopes.
RD RACING said:
Mate, what do you recomend i buy then, the only other bikes around i no of are the tricked up DRZ 110, or souped up little 50's, ex America and your talking closer to 10k us, dont no bout you but if i were spending that sort a money id want alot more than a gutless little pit bike if ya no what im saying.
fecksfx said:
gearing on my bike is all good, it was pretty shit with the 10" wheel but since the 12" it's heaps better.
I had new springs put in my front suspension and new oil, 100% better than the other cracp that was in the forks.
RD RACING
Well-Known Member
thats what i needed to know, made in china. you can not expect absolute reliability from a chinese engine / transmission. i know these bikes look great but things break to easy. if made in japan would be much better. look at the tiny ktm 50cc would a thumpstar keep up ? simular $s
yes, it would blow it away and leave it in the thumpstar dust, the thumpstar is 'one of the best pit bikes' even tho it's made in china the quality is so good it could match or even beat a same style bike made in japan.RD RACING said:
all these pit bikes are a copy of the KTM50 and the Honda CRF50
and non can match them with qualitiy.
got a CRF50 with 88cc kit and it kills every other brand pit bike i have seen.
sure a few might keep up with some mods but when it comes to reliability
they are unmatched.
the Thumpsters are proberly the best quality china bikes up there with Pitboss.
but CRF50 and KTM50 are the real deal with a huge range of aftermarket parts and backing.
and non can match them with qualitiy.
got a CRF50 with 88cc kit and it kills every other brand pit bike i have seen.
sure a few might keep up with some mods but when it comes to reliability
they are unmatched.
the Thumpsters are proberly the best quality china bikes up there with Pitboss.
but CRF50 and KTM50 are the real deal with a huge range of aftermarket parts and backing.
