Do not accept vibration!!

[bronevaya]

so I recently replaced a broken bolt, and guess what? the bike rides smooth!!

suprise!!

but seriously, it rides much smoother (it feels) then when I first got it.

I always attributed a slight vibration to it being a dirtbike (before).


I guess this is just a reminder from me to you, tighten your bolts!!

Use a torque wrench!!

your butt and feet will thank you!!

[IronFist]

I never broke a bolt, but like others here my engine mounting holes were about 1/4 inch larger than the mounting bolts. I ended up using a bigger diameter bolt to take up the space of the large mounting holes. Tightened and stayed tight after that. 8) N2r

[TeamCheap]

The stock bolts and the mis-sized holes are a real serious problem.

I had a hard time convincing some people just how bad they were in the beginning but then more and more people started seeing the same problems with the bolts.
best mod I have done yet was to change out all those engine mount bolts.

My main concern was when they break so bad that the chain piles into the case locking up the rear wheel and trashing the engine case. (I dont even want to think about the bodily damage to the rider)

thx man will do.

how do larger bolts fit into a mis sized hole? what is with the threading? i am lost here.

[Jim]

They drilled the holes to a bigger size...

I think the upper rear motor mount hole is like 10.4 something mm, I put a 10mm bolt in, half a mm is a pretty small difference... I haven't had any problems with any of the other bolts though.

[TeamCheap]

This is what I did On our bikes I just used standard grade 8 bolts with steel lock nuts.

For mine if I remember the sizes right, I used:
2= 2-1/2".....x3/8-front bracket-frame side
2= 4"...........x3/8-front bracket-engine side
3= 3"...........x3/8-top 3 hole bracket-made new brackets so holes lined up right
2= 5-1/2".....x7/16-upper/lower rear

Also had to drill the engine mount holes to allow for the slightly larger diameter bolts-scary but I feel it was the right thing to do.
It really was just cleaning up the holes except for the top engine mount hole that one actually is small.

I would have loved to find some metric bolts that fit perfect but I didnt feel like hunting them down.

I always prefer to have a bolt that has a shank(shank=smooth/unthreaded section) that will just go thru all the holes since it gives better support than the threaded sections which eventually wear out.Usually you have to give a little in order to have enough thread to tighten it all up but I always try to get it as close as possible.


Thread link HERE (http://www.chinariders.net/modules.php?name=Forums&file=viewtopic&t=1810&postdays=0&postorder=asc&highlight=standard&start=15)

I'm noticing more and more that the engines are coming with the upper rear engine mount bolt redone the way it should have been, the way I did mine and still need to do the wifes with the shorter more secure bolt and closer brackets.

[newbie555]

what is the reccomended torque for engine bolts?

[IronFist]

Zap, if you stick a bolt into a hole that is way too big, no matter how hard you tighten the nut, the bolt will move around in that hole. The engine mount holes ( on my bike) were too big. Grade 8 bolts or higher are strong enough, from what I hear. Check the bolts that mount the engine to the frame, loosen if you have to. Check to see if the hole size is too big for the bolt. If it's a good fit, retighten, and move to the next one. If you can fit a bigger diameter bolt in there, then it's probably a good idea.(sorry no torque wrench 555:cry: ) I have a pic in my gallery that shows it. You can see daylight through the engine mount hole with the bolt in the hole. Mike

[TeamCheap]

I didnt use a torque wrench, I just snugged them all up by feel plus I used steel lock nuts so I'm not sure how that would have impacted the torque wrench settings anyway.

You really have to take the bolts out and see how they fit not just give them the old looksee.
It's not something you can do real fast it's more of something you want to do right.

start with the lower rear engine mount bolt and get it right.

then with that one installed take the rest of the bolts out and get the upper rear enigne mount bolt right.

the upper and lower rear engine mount bolts are larger in diamter than the rest and I feel these are the most important to get right first then move onto the front 4 hole bracket and check/resize/replace those.

and lastly you'll most likely find the upper 3 hole brackets holes will not line up and you'll need to make new brackets(very easy to make)

[katoranger]

The engine rebolt was worth the $11 in bolts from Ace hardware.

I just had to drill out some of the holes slightly.

Allen