putting motor back together.

Finksies · Posted: February 7, 2008, 1:03 pm Post subject: putting motor back together.

IM gunna put my motor back together this weekend. My question is what silicone did you guys use on the top cover of the motor where the rocker arms are. Not sure what its called. Can i just get this from anywhere?

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

DON'T use silicone. Recommended sealer is what the factory used originally - Yamabond, or Three Bond, which is the same stuff (they make the Yamabond for Yamaha). They also make it for Honda (Hondabond) so you could use that as well. Best way I've found to apply it is to cut down the bristles on an acid or flux brush to about 1/4" to 3/8" long so they're stiffer and use that to spread it out. You get a nice even thin coat this way. It's very difficult to do that just squeezing it out of the tube.

Finksies · Posted: February 7, 2008, 3:04 pm Post subject: Re: putting motor back together.

Sweet thanks, I got a honda shop right down the street Ill just do that. Thanks again for the fast response.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

Make sure you get the right one. Honda and Yamaha have several designated by numbers. You want the #4. It's a gray semi-drying liquid (well not really liquid, more like a cream). Yamaha has discontinued it but there might be some tubes still in stock. They're coming out with a new #4 that's clear and silicone based. Maybe it will work but I'd rather stick with something I know works. I got the last tube from one of our local shops last summer. My little eyes lit up when I saw it because I knew it was discontinued.

KYLEPRESTON · Posted: February 7, 2008, 4:03 pm Post subject: Re: putting motor back together.

what is the difference between #4 and #3. besides #4 is discontinued.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

I've never heard of a 3. There's 5, 6, and 7, but no 3 that I'm aware of.

Finksies · Posted: February 7, 2008, 8:43 pm Post subject: Re: putting motor back together.

Geese didn't think there was soo much to know about yamahas gasket sealers. Thanks for the information...

oldskoolcool · Full Member Joined: Sep 08, 2007 Posts: 372

Permatex motoseal works wikkk to, i used it for my rebuild and have no leaks.

midnrider

Mike's XS has Three Bond and at a better price than you'll get at a dealership
NR

BiffTirkle

well, ive decided to pony up the cash for the new 750 big bore kit! yes, praise me! only thing is. i dont just want to put that kit on an engine with old parts! so ive decided to do this right. a complete rebuild. i'll replace as many parts as i can, that are available. ive never done a rebuild on a motorcycle engine. mopeds, yeah, plenty of times. so heres what i need to know. when putting the engine back together, do i use the gasket kits and the 3 bond? or just the 3 bond?

xsjohn

If a part is within spec....it is basically new.....

John

BiffTirkle

thanks john, that does help. sets my mind at ease. but i do want to replace new rods, bearings, valves, and such. im a bit obsessive when working on a project. i want to do everything i can.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

You use both sealer and gaskets. Some places get gaskets (head to cylinder, cylinder base, cam end covers), some just use sealer(engine top cover, crankcase halves). There's some good tips here .....

xs650temp.proboards29....1144549097

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

xsjohn wrote:

If a part is within spec....it is basically new.....

John

......exactly.

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