Apex Engine Gone...rebuilt and rebuilding again ughhhh!

[stoutner]

Probably taking apart monday or tuesday. I had to go down to florida for a few days to play some golf. Just got back. If I get it apart, I'll let you know what I found.

I'm borrowing a sled and heading for Quebec on Wednesday. Hopefully I'll get it apart before then.

 

[stoutner]

Got everything apart. Here are some pics. Cylinder looks o.k. believe it or not. Looks like I'm just changing piston, rings, pin, and gaskets and trading her in for a new ride. I do have a couple of questions???

Which cylinder is #1?

Any idea how to align cams, timing chain etc? Any info would be appreciated.

 

[aja636]

#1 cylinder is the one closest to clutch. To get it on TDC on the mag side pull the little rubber cap off/inspection hole. and you will see marks for TDC. Once you get that lined up you will get your cams in place and you will see dots. one one the cam and one on the cap. line them up, get the chain on and tighten the caps down. Make sure everything line ups once it is all tight. This is a Pain in the A$# wayne. It will take a few times to get everything to line up just right. Hopefully some one with more experience has some advise to chime in here with. but that is how I did it when I stacked head gaskets. Give me a call if you need.

aj

 

[billey100]

Not to experienced with the 4-strokes but I have an extra set of hands right around the corner if you need them this week. I am just glad I didnt take it for a burn down the track last year or I would think it was my fault.

 

[stoutner]

#1 cylinder is the one closest to clutch. To get it on TDC on the mag side pull the little rubber cap off/inspection hole. and you will see marks for TDC. Once you get that lined up you will get your cams in place and you will see dots. one one the cam and one on the cap. line them up, get the chain on and tighten the caps down. Make sure everything line ups once it is all tight. This is a Pain in the A$# wayne. It will take a few times to get everything to line up just right. Hopefully some one with more experience has some advise to chime in here with. but that is how I did it when I stacked head gaskets. Give me a call if you need.

aj

AJ,

I looked at the mag cover and found that arrow on the cover just inside that cap. On the flywheel, I see something that looks like this...

I-----I I

Do I set the arrow right in the middle of that I-----I section?

I'll look for the dots on the gears and cams tomorrow. Where is the dot on the cams?

 

[wantboost]

just got done rebuilding mine wayne.my piston looked like your pic #4 but not as bad.see how it opened up the ring land.thats what mine did.the top looks like detonation to me.better check that cylinder again.piston looks bad.my rebuild is still fresh in my head if you need any info.oh yea stopped using nitrous and went the turbo route

 

[aja636]

I set TDC between the marks on the flywheel and It worked out fine. The dots are on the cam not the gears, and they are located after the first set of caps going back from the gears.

I dropped a long handled screwdriver down the #1 plug hole so you can watch what is going on

aj

 

[stoutner]

just got done rebuilding mine wayne.my piston looked like your pic #4 but not as bad.see how it opened up the ring land.thats what mine did.the top looks like detonation to me.better check that cylinder again.piston looks bad.my rebuild is still fresh in my head if you need any info.oh yea stopped using nitrous and went the turbo route

That piston and the others are really black because I was sucking massive oil out of the airbox and into the cylinders for over 100 miles. I also ran it at least 100 miles with that pistion broken...maybe even 300 miles.

I have had dirt bikes and changed pistons on cars and dirt bikes before but have never seen this.... When I pulled the piston, I could find no sign of the top ring anywhere. No metal filings in my oil pan area and my valves and valve seats seem to be fine. I cannot even find one small piece of that top ring. Is it possible that it never had one???

 

[mbarryracing]

Wayne,
Once you detonated and melted that top land away, the top ring beat itself back and forth wearing the groove and finally broke into little chunks that worked past the burned away ring land and into your combustion chamber (wacking your plug electrode) and finally out the exhaust. That ring is in your muffler now.
I'd be looking real close at your valves in that cylinder, too. Might be dinged up at the seats and not seal so good. But Ah, your trading it in anyhow so run it...

 

[lakercr]

#1 cylinder is the one closest to clutch. To get it on TDC on the mag side pull the little rubber cap off/inspection hole. and you will see marks for TDC. Once you get that lined up you will get your cams in place and you will see dots. one one the cam and one on the cap. line them up, get the chain on and tighten the caps down. Make sure everything line ups once it is all tight. This is a Pain in the A$# wayne. It will take a few times to get everything to line up just right. Hopefully some one with more experience has some advise to chime in here with. but that is how I did it when I stacked head gaskets. Give me a call if you need.

aj

AJ,


I looked at the mag cover and found that arrow on the cover just inside that cap. On the flywheel, I see something that looks like this...

I-----I I

Do I set the arrow right in the middle of that I-----I section?

I'll look for the dots on the gears and cams tomorrow. Where is the dot on the cams?

Not too bad, most of that will buff right out.

In your description, the mark on the right hand side is the TDC indicator. Check out my build post for a bit better idea on doing the cam timing. You can give me a call whenever you want for some help.

 

[stoutner]

Laker,

I checked out your post on the rebuild. WOW! That is awesome and will save me a lot of time and peace of mind. I found the dots on each cam and am all set with that now. I'm glad you mentioned about the timing chain guide going in when you put the cases together. Man, that just saved me a bunch of time.

What is the ring gap spec for a stock pistion / rings? Anyone know?

Thanks to everyone for helping and/or offering to help.

Wayne

 

[sprtnwd4yamaha]

what is the link to lakercr rebuild post? i think i might need it.

 

[TT]

http://www.ty4stroke.com/viewtopic.php?t=32636

 

[stoutner]

Well, got it all back together and running yesterday. Took a while to prime the oil pump and then I got it fired up. Ran crisp for about 1 minute but wouldnt idle. Couldn't figure out what was hapening then...the bad news.

I was revving it to about 3500 rpm and it all of the sudden it went CLUNK!

We went Nascar style to pull the engine back out in about 90 minutes start to finish. Pulled it all apart and of course started on the lower end. Everything on the lower end looked great, nothing out of place no metal flakes etc.

Pulled off the head and found all three intake valves bent on the same #2 cylinder that was originally bad. I just have to assume that all of that debris from the piston and ring must have bent up those valves. I made the mistake of not pulling them out and checking them before I put everything back together. I wish I had! Anyway, gonna order new valves, and guides and try again.

Anyone have an Apex Head assy they want to part ways with cheap ?

 

[wantboost]

THAT SUCKS,90 min thats making some time.hope you have better luck this time around