first top end story (lil long)

[dante]

I finally decided to do it myself for the first time... I followd all the directions and everything... I practiced a couple times getting the cylinder over the old piston and old rings... then I installed the new piston and rings and put it back together... I go to torch the bolts down and one of the studs just came out... I thought it was over for sure... I pull the cylalndar back off and I realise that the stud's threads are completely gone! The shop I took it too looks like they just loaded it up with lock tight holding onto like two threads that were left...
So I went to the auto parts store bought the next size larger stud, and tap and taped that thing the next size larger... I was scared it wouldn't work, but I taped the new threrads clean and put the stud in...
That's when the fun really began... The mounting hole on the cylinder: too small... So I had to drill it out... I was afraid Id ruin it, but I did it anyway... Finally got the top end on, torched it down... If fired up right away... I drove it around for 30 minutes let it cool down...
Finally I load up the bike, to go ride at Johnson Valley nice and early get it broken it the rest of the way... I get out there and the I start the bike let it warm up then I go about 1/4 mile... bike dies, won't run for nothing... can't push it in the sand to push start it, I'm thinking of all the things that could have gone wrong... I bring it home, tear the carb apart, clean everything, I'm thinking maybe I should insect the kips and clean all that out? I mess with he mixture screw... I try and think of everything... should I tear it all back down? Finally after about half the day goes by I decide to go out and buy a new spark plug... wouldn't ya know, it fires right up after that and runs so much friggin better than I even remember it running... it's like a new bike now!!!

 

[Papakeith]

glad everything worked out.
I think (please consider the source here, I'm no mechanic) that you might have been able to get a helicoil or some other type of thread fixing insert, and kept the same size stud. Your way seems to have worked too though.

 

[bleeds]

good news!! Glad your worked out for you. I am getting ready to split the case on a Yamaha RT100J. Needs new rod bearings. We are going to go ahead and do the top end while we have it down too. I hope ours runs good when we are done!!
Bleeds

 

[dante]

glad everything worked out.
I think (please consider the source here, I'm no mechanic) that you might have been able to get a helicoil or some other type of thread fixing insert, and kept the same size stud. Your way seems to have worked too though.

your right, that's what I should have done... I just decieded to re tap it because I wanted to ride it!!! Next top end I might have it helicoiled... I am no mechanic either, that's why I'm so stoked I was able to do it... it actually ran after I put a top end in, for some reason it's amazing to me... If I can do a top end everyone should be able to figure it out... It truely was very easy, except for forgeting to buy a fresh plug, and the whole stripped threrads thing...

 

[coretex]

Im scared to do the top end on my bike looks very complicated, it aint due for a top end for another 6mnths + its practically brand new, going to be fun and games when the times comes. :(

 

[ellandoh]

youll pick it up in no time. 2 or 3 and youll be able to do it in 1.5 - 2 hours

 

[dante]

Im scared to do the top end on my bike looks very complicated, it aint due for a top end for another 6mnths + its practically brand new, going to be fun and games when the times comes. :(

It's not so bad on a two stroke... If you can already do your own fork seals, and stuff like that that you'll be fine... I recomend giving it a try, because it really is easy... JUst make sure to do it right... Install the rings with the correct side up... Torche it down correctly, in the correct "X" pattern... Get gasket cleaner and clean the gaskets off real good... Also one thing that helped me is that I practced with the old piston and rings, putting the cylandar on... That way with the new parts on their you know exactly how to do it... My 2000 kx 125 only has one ring! So mine was really very easy... Also I did'nt have to hone it or anything either, I just cleaned it out really good and cleaned out all the carbon... If you do it while your bike still runs good you'll have zero problems... And bro my friggian bike hauls now... I was starting to think I needed a 250 or something because I always found my self in sixth gear going jeese is that it, but the bike seemed to run ok, ya know... But it's a completly different bike now, amazing...