OzVMX Forum

Marque Remarks => Yamaha => Topic started by: LWC82PE on November 19, 2010, 04:41:33 pm

Title: Yamaha 50cc help/manual needed
Post by: LWC82PE on November 19, 2010, 04:41:33 pm
Does anyone have a workshop manual or know where i can download one for one of these things? Preferably need it by Monday.

I believe its a 66 or 67 Yamaha 50cc U5 which i know nothing about.

It has an automatic clutch which is slipping big time and i need to know how/where to adjust it. Do you have to take the right side engine cover off? Any help is apprieciated

Is it the same type of motor as  GT/MX 80 ???
Or JT-1 ?

Thanks

(http://farm4.static.flickr.com/3569/3663576675_7951d1305a_b.jpg)
Title: Re: Yamaha 50cc help/manual needed
Post by: Tim754 on November 19, 2010, 11:20:56 pm
Its a rotary valve engine like the JT60 not like GT/MX80.
Title: Re: Yamaha 50cc help/manual needed
Post by: LWC82PE on November 20, 2010, 01:15:33 pm
Ok that helps a little. Every thing i can find only shows manual clutch though. Hard to find anything with auto clutch.
Title: Re: Yamaha 50cc help/manual needed
Post by: Tim754 on November 21, 2010, 08:19:16 pm
May be like the old Aus post 2 stroke Yammies V90? Still looking for you. Cheers
Title: Re: Yamaha 50cc help/manual needed
Post by: DR on November 21, 2010, 09:00:39 pm
the 1969 U7 parts fiche at http://www.cmsnl.com/yamaha_model8287/ (http://www.cmsnl.com/yamaha_model8287/) may give up a clue..though I can't see any means of adjustment :-\
Title: Re: Yamaha 50cc help/manual needed
Post by: LWC82PE on November 21, 2010, 11:27:47 pm
Thanks guys. i just found that U7 parts book tonight too. That appears to be the one.
Title: Re: Yamaha 50cc help/manual needed
Post by: LWC82PE on November 22, 2010, 05:18:31 pm
Well i took the cluch cover off today, cleaned the friction plates, bead blasted the steels and put it back together with fresh oil and now the clutch and gears work properly but the damn thing misses pretty badly. The plug is a B8HS which is a new one the owner put in but i have no idea if thats the right one for it. Ive been right through the carby the otherday as it was full of crap and fitted a new main jet but couldnt get the short mikuni hex and had to go with the long hex but i dont think thats a problem. What sort of points gap should this have? i was thinking 0.30-0.40mm as thats what some specs for some later 50cc yams said.

By the way the barrell says U5 on it so its definitely that model.