Spark partial failure at mid to high.. Ive tried it all!!

[barnett468]

goo,not too

[McQuade]

I cleaned the tank professionally at work, new fuel.
As a side note, the other day I was trying the choke, which operates, the engine would work about the same, but quieter as the back fire through the carb wasn't as loud. But it didn't flood out.. It sounds lean, acts lean, but plug says rich. I'll update on timing with it wired.

[McQuade]

Ok got some answers here.
Put a good irridium plug in and tried the timing light.
At idle, F line was slightly left of the notch in the case. As I accelerated it became hard to follow but moved quickly to the right /towards the rear of the bike. I mean barely touching the throttle. I turned the timing lights advance dial and the line goes the opposite way. It seems to fire without incident, no faltering that I noticed. Just the timing quickly jumped out of sight and was sparadic on position. It seems to actually be retarded by a few degrees, yet my pickup coil is turned max counter clockwise..

[McQuade]

Checked idle with my buddies fancy DVOM it was at 926 but it's lowest setting was 2cyl, so I'll wager around 1852 or so. Removed muffler, and the clip on the carb needle is at the top attempting to cute it's rich behaviour. Better but nowhere even close to hauling itself without me on it.

[barnett468]

OK . . if the pick up coil is on the left side of the engine, counter clockwise would be retarded and the F to the left of the mark would be retarded . . I would try wiring the advance closed as I suggested . .

[McQuade]

Whoops neglected to mention I did wire it solid. It would barely climb off idle. No bawls. And I forgot my clocks, I meant all the way clockwise haha. Fully advanced. In which your reply will most likely be "valves are skipped on te chain" to which I come to another digression. My dot won't QUiTE match up. Pretty effin close tho. And I tried numerous times skipping a tooth on the sprocket trying to get it on, but one tooth either way and it's way off. So that being said, I've called a priest to come exorcize whatever resides within this thing. Haha

[barnett468]

Ok . . I am stuck on a tiny fn tablet until to borrow afternoon. So its hard to do this.

please be more accurate and concise in your descriptions . . for example, you have not mentioned if it quit missing during any of this . . obviously if it no longer revs to the rpm at which it was missing before we can't draw any conclusions as to weather to miss is now gone etc.

It sounds like it might be helpful to allow it to advance but only around 1/2 of the current amount . . this would require some type of stop . . at the very least, it sounds like there is not enough tension on the springs but that being said, if it is in fact idling at 1800 the advance would already be advancing some so why would it be slightly retarded at idle?

As far as the can goes I'm not sure what you are talking about so here is some info . . the t on the flywheel should be lined up with the mark . . the one on the can great should be lined up with the mark . . if the chain is stretched, the line on the can gear will be going to the rear of the bike by maybe 5 mm or 3/16 of an inch . . the line should never be towards the front of the bike . . if it has a non stock can, it is possible that the holes in the can are not in the same location as the orig can . . this would cause the can mark to be misaligned .. . I have seen this before with some cams.

Do you know ewhat that can is?

[McQuade]

When I wired it closed, it didn't get high enough rpm to get to the "danger zone" where the issue resides. From what you describe, my chain is indeed stretched. But I've never seen an issue of this severity from that amount. The cam is OEM lobes were pristine when I checked the top end during the head gasket.

As a side note ephiphany ; what would happen if the flywheel spun on the shaft, is this possible, and should I be able to see a key way on the crank? I see one on the flywheel but not on the crank, which seems to defeat the purpose.

[McQuade]

My thinking is the flywheel shifted... As my timings retarded from the get go, how could it backfire through the carb, unless my mechanical valve timing is off from tdc?

[barnett468]

It can also do that if the ignition timing is off or it has a huge can and carb etc.

If you have a burnt/leaking in brake valve it will do it to some degree too.

[McQuade]

It can also do that if the ignition timing is off or it has a huge can and carb etc.

If you have a burnt/leaking in brake valve it will do it to some degree too.

I found a key... Under the flywheel, caught behind it.. Lol

[barnett468]

When I wired it closed, it didn't get high enough rpm to get to the "danger zone" where the issue resides. From what you describe, my chain is indeed stretched. But I've never seen an issue of this severity from that amount. The cam is OEM lobes were pristine when I checked the top end during the head gasket.

As a side note ephiphany ; what would happen if the flywheel spun on the shaft, is this possible, and should I be able to see a key way on the crank? I see one on the flywheel but not on the crank, which seems to defeat the purpose.

You need to actually remove the flywheel to inspect the key . . yes they can and do occasionally spin.

A can that is off by 5 mm or less from the mark in the cam gear will not cause this proble .

r

[McQuade]

In the bottom of the case I found a key.. I will pull the flywheel(I never pulled it)

[barnett468]

In the bottom of the case I found a key.. I will pull the flywheel(I never pulled it)

OK, I didn't see that before you posted . . yeah, thats kinda suspicious, lol.

[McQuade]

Well I have given up. That effin flywheel will NOT come off. I now have play in and out so either it moved or I beat the crank bearings out of it. Either way it will not move any further.