may be worse than i thought...

deadchef

deadchef

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ok, went out to reconfirm my timing. at idle it's at full advance. if i give it some throttle it advances further and then starts stumbling like normal. can't retard the pamco anymore.

granted, this thing hasn't run right since i got it but could this be the real reason behind the stumbling?

saw this article from another thread...
http://www.650motorcycles.com/CamTiming.html

it shows a way you can confirm the cam timing by just looking at the pin alignment for the advance mechanism. the article says it should be vertical.

here is where mine is at tdc...
C517F288.jpg


can i assume i'm screwed?
 
its an easy fix!

Im not even sure how people manage that.....hmmm, the marks dont line up where the manual says they are saupposed to...Better peen the cam chain master and put it back together.

The cam can also go in backwards FYI.
 
its an easy fix!

Im not even sure how people manage that.....hmmm, the marks dont line up where the manual says they are saupposed to...Better peen the cam chain master and put it back together.

The cam can also go in backwards FYI.

threaded end on cam should be on the right hand side of the motor as if you were sitting on the bike.
 
well that sure messy's up my day... but somewhat relieved to finally figure out wtf is wrong with this bike.

it's like a really bad prank the po pulled on me. anyways, time to nut up and get it done.


so i think i'm good as far as getting everything out and opened up. just a couple q's for now and probably more when i get down to it.

1. i think i've come across some threads where you can pull the cam without breaking the chain. can i get the cam in the correct position without replacing the chain? i think i can just pull the bearings off one end and remove the cam chain tensioner to give it enough slack to remove the cam?

2. anything i should look for while i have the top cracked open? anything else i should attend to? any gaskets that should be replaced?


thank you all, this site rules!
 
deadchef said:
well that sure messy's up my day... but somewhat relieved to finally figure out wtf is wrong with this bike.

it's like a really bad prank the po pulled on me. anyways, time to nut up and get it done.


so i think i'm good as far as getting everything out and opened up. just a couple q's for now and probably more when i get down to it.

1. i think i've come across some threads where you can pull the cam without breaking the chain. can i get the cam in the correct position without replacing the chain? i think i can just pull the bearings off one end and remove the cam chain tensioner to give it enough slack to remove the cam?

2. anything i should look for while i have the top cracked open? anything else i should attend to? any gaskets that should be replaced?


thank you all, this site rules!
Click to expand...

1. Yes

2. Check out the condition of your front cam chain guide.
 
Patches said:
1. Yes

2. Check out the condition of your front cam chain guide.
Click to expand...

1. Agreed, when I put my engine back together the first time my cam timing looked like yours. I had it fixed in under 2 hours including taking the motor out of the frame and putting it back in. Just bump the cam bearings off and you will be able to pull the cam chain off the sprocket and to the side and then you'll be able to wiggle the cam out.

2. Agreed.
 
ok, here we go...

taking my time, this took less than two hours. homemade snowmobile ski dolly works well for an engine stand.
2A89F408.jpg


were these things painted black from the factory?
62D7498A.jpg


exhaust. should i be concerned about the amount of carbon buildup? anything i should do?
C96F76A9.jpg


here we are at tdc. po was close right? :doh:
617465BC.jpg


this is where i'm at now at tdc. is this close enough? seems just a hair off to the right... :shrug:
2A90725C.jpg
 
coughing skunk said:
1. Agreed, when I put my engine back together the first time my cam timing looked like yours. I had it fixed in under 2 hours including taking the motor out of the frame and putting it back in. Just bump the cam bearings off and you will be able to pull the cam chain off the sprocket and to the side and then you'll be able to wiggle the cam out.

2. Agreed.
Click to expand...

when you had this issue, did the bike run at all for you?
 
mine ended up like that too. runs great, one kick bike.
in the pic its hard to tell, but there should also be a faint line that is parallel to the cam cover seam, on the left.
As far as the po playing a prank on you, look at it this way, the po rebiult it, never got it to run right, and didnt know how easy this fix is, so he sold it to you, the proud owner of a possibly rebiult motor.
 
deadchef said:
another q, do i have to use yamabond or can i use any silicone based gasket sealer for the head cover?
Click to expand...

i use a thin smear of permatex moto seal. If the chain is a bit strecthed that is why your mark probably looks a bit off. I have always done new chains so they are tight and the marks always line up. Put the tensioner on the rear and see how it looks. Make sure your cam is centered on the head where the bearings sit. If its to far to one side the back part of the points covers wont seal up against the head and youl leak oil.
 
Can't tell a thing from that photo. You need to check the position of the notch with the slack out of the front run of the chain, and yes, installing the adjuster will do that for you. Once you have that done, jam-fit a line in the hole in the crankshaft center with whatever you have on hand (wooden barbecue skewer, small wall anchor and screw, etc.) and pull the line up across the camshaft center. The notch needs to be exactly parallel to the line.
 
deadchef said:
when you had this issue, did the bike run at all for you?
Click to expand...

The first time no, but my timing was off a little bit more than yours. The second it did run, but my timing was still off and it pushed all of the power to the upper RPMs. It had extreme difficulty moving from a stand still. The third time it was (and still is) spot on and runs great.

You need to have the cam chain tightened like everyone else has said. My chain is stretched a little bit and my timing alignment looked like yours. Install the chain tensioner and check. I find it easier to look at the pin in the advance rod rather than the mark on the sprocket.

Be wary though, and someone might dispute me on this, when you place the head on and torque it down it will compress the gaskets, etc and bring the cam closer to the crank. This in turn changes the timing adjustment, and it has a more pronounced effect when the timing chain is looser.
 
Last edited:
grizld1 said:
Can't tell a thing from that photo. You need to check the position of the notch with the slack out of the front run of the chain, and yes, installing the adjuster will do that for you. Once you have that done, jam-fit a line in the hole in the crankshaft center with whatever you have on hand (wooden barbecue skewer, small wall anchor and screw, etc.) and pull the line up across the camshaft center. The notch needs to be exactly parallel to the line.
Click to expand...

nice tip. i'll try this when i get home.

thanks!
 
Yeah, it's easy to overtorque those buggers. Shouldn't happen again though. I believe the next time I take a head apart I'm going to leave the banjos and the oil feed line attached and just break it loose down at the crankcase......
 

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