third gear slipping?

[theMINDLESSone]

hey guys, ive just gotten around to finshing my nephews bike and i bought an engine for it. 125 ducar. all is well, starts good, first and second come on real well, but third slips. just on and off. im not that much of a noob but i dont have much hands-on with ducar or gears and stuff. im assuming its the gear selector/drum? come loose or anything?

cheers

 

[sean01]

problem might be the gear drum star shift but more than likely the gears have been toasted..
the gear locating blocks (dogs) wear the edges off them and cause them to fade in and out of gear..

you should be able to go down from 4th to 3rd and feel no problem till you accelerate again.

unfortunately if this is the problem there is no quick fix and the whole engine needs to be split and the offending gears replaced. i find it easier to change both gear sets..

 

[theMINDLESSone]

sounds like a b!tc#.. how hard you recon it is to change the gears?

 

[sean01]

well im not going to lie to you lol, 99% of the components need to be removed. and if you havent done it before it will mess with your head..

 

[theMINDLESSone]

damn.. wish there was a way to check all this before buying an engine..

 

[aus_yzman]

I feel for you , just depends if you want to spend $100-$120 for gears and gaskets plus whatever special tools cost and spend 4-6 hours rebuilding engine or $300 for new 125cc .

 

[sean01]

yep i generally dont bother with secondhand engines unless there really cheap and i plan to do a full rebuild anyways..

stick to new engines and youll have a better experience

 

[theMINDLESSone]

i just paid over 100 on this one! damn bastard lol note to self, never buy an engine off a 13 yo that tried to sell you a 125 as a 140..

 

[sean01]

lol, oh well as they say.. live and learn..

also no harm in trying but the let down does get to you..

 

[theMINDLESSone]

ill give it a crack.. doubt ill get half way tho haha