Timing advance question

Dieselchanic

Dieselchanic

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When I bought my 81 xs650 the guy told me it had a blown head gasket. I didn't argue and didn't even check it out that close because I knew with the parts on the bike it was worth what I was giving for it. So I started checking it out a bit. Pulled the plugs and kicked it over, hot spark. Ok good. I choke it and kick it over for a bit, no love but it's making a whooshing sound as it rolls over. I deduce thus us coming from the crankcase breather (it's wide open). Well that's normal ish. As I continue to kick it I realize this beast is a bastard to kick. It wore me completely out. So it's got a blown gasket but still enough compression to kick like a mule? I gave it some ether and kicked it. It hit and almost threw me... It hits hard. But it hits right before it should cuz it kicks back. Every time. I've read that a stuck timing advance will cause a hard starting issue so I peeked at that. This is what I found:

sugymese.jpg


That's something jammed in there to hold the weights out... Umm??? It's also all rusty in there.

So I'm thinking that even if the gaskets blown if it's got enough juice to crackle and pop on ether it should try to run a little? It doesn't. It just kicks back.

So what do you guys think my problem is? Blown head gasket? It funky timing?
 
Well, first thing is first, take out the advance weights, springs, and rod. Clean excessively, re grease and reassemble. With the advance all jimmied up like that there is no way it will run correctly. Use the forum search function to find threads about each step, then do them in this order.

1. Fix the advance unit.
2. Set the cam chain
3. Adjust the valves
4. Check and set the timing
5. Kick the sucker
 
Funky timing. Part of the static ignition timing procedure is to jam the flyweights open so you can statically set/check the advanced timing. Looks like someone forgot and left those in there. Just remove them (after you've confirmed the advanced timing), and check for advancer freeplay...
 
Yes, your timing is jammed in the full advance position. That's for running at 3K plus RPMs. That's why it's kicking back and won't start. As an aside, an '81 shouldn't have an ATU or points. Someone's been (parts) swapping things around. Your pic is too blurry to tell but the ATU could be out of time with the points cam as well. It's possible to assemble the advance rod with the locating pins for the ATU's little disc and the points cam off by 180°. That throws the timing off by 180°.
 
>Should have mentioned. This thing has Pamco ignition. Not sure if the advance is still in use?

The original Pamco ignitions use the mechanical advance, there's a newer one that doesn't. Most likely you have an older one.
 
Ok. I've been reading and it looks like the mechanical advance on my bike is still functional, or should be. It's a long ways from functional in its current state.. So that's next on the list, to rebuild the advance unit.
 
Best to remove the advance rod and check everything out.

I was wondering what was going on. An 81 motor didn't have points or mechanical advance.

Some one has found and old unit, (rust), and installed it with the pamco. Things to look out for is cracked cam. MikesXS sells bushings that are to big for the cam and some people have forced them in place and cracked the cam ends.

I would dissemble and check everything out, lube and reinstall. Check the weight spring tension as well. Or just throw away the mechanical advance and buy a Pamco E-Advance, just make sure you have the right pick up is for an E-Advance.
 
Well I pulled that wadding mess out of the weights and the little nubs that go into the shaft are gone!! Plus being all rusty, and as Gary mentioned vacuum lines off.... No wonder it didn't run for the dude.
 
650Skull said:
Best to remove the advance rod and check everything out.

I was wondering what was going on. An 81 motor didn't have points or mechanical advance.

Some one has found and old unit, (rust), and installed it with the pamco. Things to look out for is cracked cam. MikesXS sells bushings that are to big for the cam and some people have forced them in place and cracked the cam ends.

I would dissemble and check everything out, lube and reinstall. Check the weight spring tension as well. Or just throw away the mechanical advance and buy a Pamco E-Advance, just make sure you have the right pick up is for an E-Advance.
Click to expand...

Just for clarification. The E-Advancer will work with either the new design sensor or the original design PAMCO. For those of you who have the original PAMCO with the mechanical advancer, this allows you to replace the mechanical advancer without having to buy the complete new system. However, if you have one of the early PAMCO's with the 90 degree rotor, that does have to be replaced with a 60 degree rotor, also available separately.

www.yamahaxs650.com
 
pamcopete said:
Just for clarification. The E-Advancer will work with either the new design sensor or the original design PAMCO. For those of you who have the original PAMCO with the mechanical advancer, this allows you to replace the mechanical advancer without having to buy the complete new system. However, if you have one of the early PAMCO's with the 90 degree rotor, that does have to be replaced with a 60 degree rotor, also available separately.

www.yamahaxs650.com
Click to expand...

That's why i mentioned the Rotor, (pick up), because i got caught out on the 60 and 90 Degree rotor differences

I was following your E-Advance thread and when they first come out i bought one. Didn't know the rotor was changed and when buying from your site didn't notice the statement about the change. Ended up with an E-Advance and still can't use it.
 
Dieselchanic said:
Well a new auto advance setup is $69, versus the E-Advance for $95. Kind of a no brainier. I think I'll need the other rotor too though.
Click to expand...

If you are talking about Mikes ATU I would suggest looking at some of the problems people on here have had with his ATU's, in particular the springs being sub-par and weak and the main ATU plate breaking, before ordering one of those. Your $26 savings may end up costing you more than that in the long run. You may be able to find some of the OEM fly weights from a forum member or on e-bay.
 
pamcopete said:
650Skull,

www.mikesxs.com sells the 60 deg. rotor separately. Part #14-0703.
Click to expand...


Pamcopete,

Yes and he charges $37.00 freight on top of the rotor price, $35.00. I also need to change out the failed copper cap for the newer type and i don't see the new cap as a stand alone part.

Considering selling the E-Advance and getting my money back and buying the better kit with all the parts in one go. Cheaper in the long run unless i can get all the parts i need from you.
 
ippytattoo said:
If you are talking about Mikes ATU I would suggest looking at some of the problems people on here have had with his ATU's, in particular the springs being sub-par and weak and the main ATU plate breaking, before ordering one of those. Your $26 savings may end up costing you more than that in the long run. You may be able to find some of the OEM fly weights from a forum member or on e-bay.
Click to expand...


No man, you read me wrong. The $26 extra for the E-Advance is well worth it IMO.
 
Dieselchanic,

Chances are you already have the 60 degree rotor. The 90 degree rotor hasn't been shipped for about three years. Here is a pic of the two:

6090.jpg
 

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