Need some help with my first rebuild

Hmm..I'll have to see if I can find some pullers. They aren't yamaha specific, are they? Because I know the quads I've worked on require a special yamaha-style flywheel puller. I'll probably just take it to the local repair shop and see if they have the tools I need. I'll probably be there anyway..lol.., my piston pin is stuck inside the melted piston and I'm thinking I'll need to use their press.

Tomorrow I'll finally be able to get the bottom end out of the sled and hopefully start digging into it...I'm almost excited to work on it..hah..
 
Well today I started on it and I somehow didn't realize that I had to remove the primary to get the engine out, so now I'm waiting on a clutch puller. I'll be delayed a few more days..haha...

I can't wait to dig into it though...
 
RTYsxv said:
Well today I started on it and I somehow didn't realize that I had to remove the primary to get the engine out,
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I do believe we mentioned you need to pull the primary and the fly wheel/stator to do this repair...lol
 
I knew they would need to come off, I just didn't think that I needed to pull the primary off before I pulled the engine out of the sled. I didn't look at it closely enough before..lol..I was planning on getting a puller just I didn't know I needed one right away.
 
You can get a puller around $20 richierich on here sells them. Very good tool to have and keep around
 
Well today I ordered a clutch puller from Rich Motorsports, $26 shipped so hopefully that will be here in a few days.

I have everything disconnected except the bottom coolant hose, so once I get the primary off I can pull the motor.

Tonight I decided to clean my other 2 powervalves since I couldn't really do anything else, this was my first time doing this and wow...there was a lot of gunk on there. I doubt that they have ever been cleaned in the sled's 1500 miles. The cables looked good and there weren't and pull thru issues. I couldn't pull the things out by hand, and I didn't want to damage the finish, so I had to use a little wood dowel rod and a little hammer to lightly tap them out from the front, it worked pretty well. That carbon junk is some nasty stuff..haha. One thing I noticed though, is that the PTO side valve had been leaking a little from the housing and the buildup in there was a lot more liquid and oily compared to the middle valve, which didn't leak from the housing and was "dryer" inside.

Any thoughts on why there would be a difference? :dunno: Also, notice in the pic that one has kind of a brown color to it?

Anyways I tried putting Scotch-Brite on the stuff and that hardly even touched it, so I ended up going with the razor blade method. After about a half hour of scraping and a final wipe with scotch brite, I had them both looking pretty good. ;)! Then I went to the cylinders, and found that I really couldn't do a whole lot in the little space. I ended up wrapping a paper towel around the dowel rod I used earlier and I tried to clean out as much as I could. It didn't look too clean afterwards but both powervalves had more than enough room to slide freely. I wonder how much power I was losing from having these things gunked up? I've read about people saying it feels like a new sled after these are cleaned..lol..can't wait to get this thing back together...though I'm going to have to take my time and be patient! :wink:

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tomseal6 said:
You can get a puller around $20 richierich on here sells them. Very good tool to have and keep around
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Yep, I ordered one. I've heard that the ones he sells are pretty good, and they're not too expensive either. Thanks though.
 
Did you split the case yet? How is the rebuild coming alaong. I would have Bruce just send you all the new parts you need when he sends your cylinder back to you. IE; piston, rings, seals, gaskets, wrist pin and wrist pin bearings.
 
Well today I got to use my clutch puller. I put it in there and used a 3/8 ratchet to turn it and it felt solid, so then rather than crank on it too hard I took it out and pumped the hole full of grease like some have mentioned, put the puller back in, gave it a hard turn and the primary popped right off. It worked great with the grease, thanks for the advice guys!

I got the engine out of the sled and that's about it. I took the motor mounts and the reeds out, tomorrow I'm going to see about getting the flywheel pulled off and the cases split. I'll maybe get pics tomorrow if I have time to get much done on it.

I got a piston and pin from mrviper700, and when I find out everything I need for parts I'll have CB Performance send them with the cylinder that they fixed up.
 
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Ok, so this morning I got everything taken apart except the oil/water pump shaft.

The first thing I needed to do was get the flywheel off. I needed to take the three allen head bolts out to remove the starter pulley. They were in there very tight, and to my dismay I rounded two of them out....allen bolts suck. Getting them out actually wasn't that bad though. I drilled into them about 1/4", and used an EZ-out with an electric impact driver and popped them loose right away. I got luckt, that could have been a lot worse.

I didn't have a flywheel puller. I was "inspired" to make my own by kimoaj's 13 page long V-Max 4 rebuild thread (I read the whole thing btw..lol..and learned a lot). So KIMOAJ, if you ever read this, thanks alot!!

Anyways I found a circle piece of 1/4" plate steel out in the machine shed that I believe came from an old John Deere cultivator. I used the holes on the starter pulley that I had just removed as a template, and drilled the three holes into the circle. They lined up with the threaded holes in the flywheel.

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Then I found another little piece of steel (from the same cultivator..lol) to use as a spacer between the puller and the crankshaft. I threaded three of the short case bolts into the flywheel thru the puller, tightened them down, three taps on the end with a little hammer and it popped right off. It worked great - and it was a whole lot better than spending $50+ on a flywheel puller.

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After I got the flywheel off, next came the stator. I've heard about the bolts stripping, so I found a big screwdriver bit that fit perfectly, and carefully used a 1/4" socket and ratchet to break them loose. It went fine, but why doesn't Yamaha just use regular bolt heads for these? Same with the starter pulley bolts that I did strip out, why can't they just be regular bolts?? :dunno:

I took the pistons off next so that I could split the cases. I noticed some interesting things. First, the PTO and Center pistons looked different than the stocker I got from mrviper700. They appeared to have some kind of darker coating on them. Another thing, the skirt on the middle piston was notched in two places (see pic). So now I'm thinking that this engine has been apart before! And it had only 900mi on it when i got it...
Anyone seen anything like this (notches) before? Is this OK? Also, how does the piston wash look?

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I split the cases apart and took the crank out. Everything appeared to be fine, all the bearings looked and felt good as they should - there's only 1500mi on the engine. The seals looked fine too, even though I'm going to replace them.

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Take a close look at this pic. Notice the black gunk on the case where the mag side cylinder (the one that burned down) was. Could that indicate a leaking base gasket? Could that have cause the burndown?
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Any help I could get would be great, thanks.
 
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It was the mag side piston, right...the oil stain on that side of the cases are from the weep hole of the power valve housing, as that cylinder leaned out it ran rich with oil...or...there was dirt in that carb, causing the (needle to hang up) fuel to poor into that cylinder...fouling that plug...just wash it off, also clean them upper thread bolts...I gave mine a coat of dry graphite spray...
 
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