Another #1 cylinder cold thread!

[sparkfly88]

I can't recall, did you try switching the 1 and 4 spark plug wires to see if the problem moves or stays the same?

I tried to, but the idiots that worked on my bike got rid of my nice evenly cut suppression wires, and slapped on some copper core I think. And cut them uneven to the point of I cannot switch the two wires...

[bikerphil]

Ok, are you sure you have spark to that cylinder at all times? You can hook a timing light up to that wire and see if it is firing evenly.

[sparkfly88]

I'm positive I have even and lots of spark.

We timed it a couple weeks ago using cylinder one...

[fredintoon]

I tried to, but the idiots that worked on my bike got rid of my nice evenly cut suppression wires, and slapped on some copper core I think. And cut them uneven to the point of I cannot switch the two wires...

Are the plug wires long enough to swap #1 with #2 & #3 with #4? Do that and then switch the coil feed wires.
If it's an iggy problem #2 should stay cold instead of #1.
To see if it's fuel, feed the non-firing cylinder with gas from a Bernz torch.

[sparkfly88]

Number 1 intake gasket was thin and fuel soaked. So that may have been the problem.

Sealed with a fast bead of RIGHT STUFF.

Now I'm working on doing the same to the other three.

[bikerphil]

Yep, it's a good idea to wipe any excess from the inside with your finger and smooth it out so there won't be a lip in there to impede the air/fuel flow.

[sparkfly88]

Yup, I'm doing that, I remembered reading about it.

[sparkfly88]

All four "gaskets" were soft and falling apart when I removed them from the engine.
I guess I should have listened to the general consensus about the paper gaskets. I just used them because they came in the kit. Figured they were meant to be used.... Guess not.







Also, someone decided to take it upon themselves and mill a little out on my number 4 intake... I wonder why....

[sparkfly88]

Okay. So check this out.

I was messing with all the vac ports while it was running.

Cylinder one, has a distinct push, pull going on.

A jet of air comes out of the port, then gets sucked back in.
So.... One of my valves are stuck open, or closed.... Huh?

[trbig]

Hopefully just needs a valve adjustment. Did you ever get to your friend's place for a compression check? That would have showed up there.

As these engines wear, the distance between the shims and the cams shrinks (The valve head seats deeper into the head, closing the valve to cam distance). Hopefully a valve didn't get burned.

And if a vlave was opened just a tiny bit, the air couldn't readily escape at the higher rpms.. which would have enough compression to fire then. but not lower rpm. Exactly the problem you're describing.

Now... Shim your valves and quit jackin' with your carbs!

[sparkfly88]

I have not.

I was gonna get the compression checked if the intake sealing didn't fix the issue.

Guess I have to either find a way to his place... My jeeps headgasket is blown, and now my bike I'm afraid to ride more.... Lol... Decisions...

[trbig]

Well.. no real need to get a compression check now. As you can see, you have an intake valve not closing for some reason.. either shimming or bent. When you go to do the check, if there's no clearance between the valve and the cam (With the cam lobe pointed away from the bucket) then it'll most likely just need to be shimmed. If the gap measured is something really really large.... bent valve hanging open.

[sparkfly88]

Well, since it's something pretty bad ( to me )
Getting into a DOHC and valve shims...n such ( stuff I've never dealt with )

I wanna make sure I've got my bases covered, so today I spent the rest of the afternoon removing the head offa my jeep.

What I thought was a blown headgasket, was actually 3 bad expansion plugs...

At least I now have an excuse to get the valves done and have the head checked out on it.

[trbig]

It's not as bad as what you're thinking. You'll need to pull the seat/tank, then the valve cover. There's a way to do this so you won't lose your timing or anything. Hardest part will be figuring out which shims you need, since you'll be checking them all while you're there, and getting your valve cover to seal back up completely on installation. I've had the best luck with no gasket there and The Right Stuff gasket maker, but it's still @ a 50/50 chance whether I get it sealed completely with no tiny seeps or not.

If it is a bent valve, it's still fairly easy to pull the head.. so don't even sweat that, but here's to hoping for just needing shims.

[sparkfly88]

Well, I needed something fixed within the week... My jeep is already apart and the parts are waiting for me to install.

The bike would have taken me some time because of ordering or finding shims... Then hoping it's not a bent valve...

I needed a vehicle. ASAP.