55mm TB install, HELP

[speedyman]

I took it apart and it appears that everything lined up. The dots on the cams and the gears looked to be where they should be. Damn, I'm stumped.

[hrdtail78]

Have you taken the tops off the rocker boxes?

[speedyman]

Have you taken the tops off the rocker boxes?

   Yes, all appears OK there. Pushed down hard on the lifters and none collapse. This is driving me nuts.

[FSG]

Have you got the PR's mixed for that cylinder, Intake is silver, Exhaust is black?

[speedyman]

Have you got the PR's mixed for that cylinder, Intake is silver, Exhaust is black?

Never thought about that possible mistake. I took out the pushrods earlier today and can't remember exactly which way they were.  Would the intake valve never close all the way if it were driven by the longer exhaust pushrod. That could be the problem. Is there anything else that would cause "0" compression on one cylinder. It ran great with the TW555s. All I did was install the  TW777s and 55mm Throttle Body.

[autoworker]

Have you got the PR's mixed for that cylinder, Intake is silver, Exhaust is black?

There you go.I've heard a few stories about this happening.

[FSG]

Yes that Exh PR is .125" longer and is guaranteed to hold the Intake Valve open all the time.

Easy and quick to lift the Exh PR Cover to take a look, if it's black you OK, silver you have them wrong.

[WideWildGlide]

  please let us know, as we all are learning from one another

[speedyman]

I've got to put it back together after work today and see how it pumps. I'm thinking that this had to be mistake I made. I sure hope this is the problem, I can't think of what else it could be. Thanks again for all the help! Will keep you guys updated.

[BVHOG]

"I'm thinking the bike would not run at all if the cams were installed incorrectly. It seems kinda  idiot proof with the key way on the cam gear and the alignment flat on the crankshaft."

Nothing is idiot proof. I've seen em run one tooth off cam-cam and one tooth off crank to cam. Trust me, it happens.

More often than it should, the one's I have seen seem to always have the front advanced a tooth.
But for the original poster, you really are setting your expectations high to think that you can put in a canned map and have a good running motorcycle, it very seldom happens. I hope the pushrods are your problem as the only other explanation is either the heads have been machined too far and the pushrod may be too long on one cylinder or you dinged a valve

[speedyman]

I reinstalled the cams with everything lined properly. Then reinstalled pushrods and rocker plate on the rear cylinder. Turned the rear wheel around and around. No compression at all. WTF? Taking the heads off next. I guess I have a bent valve? This is a PIA!

[hrdtail78]

Can you perform a leak down?

[BVHOG]

I reinstalled the cams with everything lined properly. Then reinstalled pushrods and rocker plate on the rear cylinder. Turned the rear wheel around and around. No compression at all. WTF? Taking the heads off next. I guess I have a bent valve? This is a PIA!

Try rotating it with the pushrods out and the head still on, you will hear very shortly if it is getting by a bent valve and can hear which one it is

[q1svt]

Can you perform a leak down?

And it would be faster and easier than pulling the PR's

[speedyman]

I reinstalled the cams with everything lined properly. Then reinstalled pushrods and rocker plate on the rear cylinder. Turned the rear wheel around and around. No compression at all. WTF? Taking the heads off next. I guess I have a bent valve? This is a PIA!

Try rotating it with the pushrods out and the head still on, you will hear very shortly if it is getting by a bent valve and can hear which one it is

Just did that with the pushrods removed from both cylinders. The front pushes air out the spark plug hole great as it should. The rear pushes no air out the spark plug hole. Looking at the intake valve thru the port(heads were ported last year and 1.94" intakes installed then) appears intact and seated normally. It must be either the exhaust valve or a hole in the piston. Will get the head off tomorrow.

I don't know about the leak down test. I have a compression tester. The cylinder does not seem to hold any pressure at all. Will know more tomorrow when I get the head off.

[BVHOG]

I reinstalled the cams with everything lined properly. Then reinstalled pushrods and rocker plate on the rear cylinder. Turned the rear wheel around and around. No compression at all. WTF? Taking the heads off next. I guess I have a bent valve? This is a PIA!

Try rotating it with the pushrods out and the head still on, you will hear very shortly if it is getting by a bent valve and can hear which one it is

Just did that with the pushrods removed from both cylinders. The front pushes air out the spark plug hole great as it should. The rear pushes no air out the spark plug hole. Looking at the intake valve thru the port(heads were ported last year and 1.94" intakes installed then) appears intact and seated normally. It must be either the exhaust valve or a hole in the piston. Will get the head off tomorrow.

I don't know about the leak down test. I have a compression tester. The cylinder does not seem to hold any pressure at all. Will know more tomorrow when I get the head off.

Put your plug back in and try to turn it again by hand rotating the rear wheel. Then listen to where the air is coming out. Chances are even looking in the port you won't see a slightly tweaked valve

[hrdtail78]

A leak down is a regulator that allows you to put 100psi into the cylinder through the plug hole.  With the second gauge you can see how much psi it is holding.  In your case it would be helpful. You can hear where the air is escaping from.  Rings, intake or exhaust.  Bob is saying to do the same, but use the pressure in the cylinders.  If you don't have one and plan on removing heads anyway.  Doesn't matter.  So you went from Wood's 555 to 777?  Shaved heads, 1.94 valve, and contact.

There are just as good and cheaper ones out there.

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=650761&group_ID=675553&store=snapon-store&dir=catalog

[speedyman]

A leak down is a regulator that allows you to put 100psi into the cylinder through the plug hole.  With the second gauge you can see how much psi it is holding.  In your case it would be helpful. You can hear where the air is escaping from.  Rings, intake or exhaust.  Bob is saying to do the same, but use the pressure in the cylinders.  If you don't have one and plan on removing heads anyway.  Doesn't matter.  So you went from Wood's 555 to 777?  Shaved heads, 1.94 valve, and contact.

There are just as good and cheaper ones out there.

http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=650761&group_ID=675553&store=snapon-store&dir=catalog

The heads were done last year when I installed the TW555s. The only thing I did this time around was the TW777s and a 55mm TB.

[FSG]

So were the PRs in the right way?

[laserp]

Did you have the lifters on the cam base circles when you chriscross tightened the rocker plates? Then, waited for them to bleed down before rotating the other cam set to their base circle? If not, you may have tweaked a valve during install.

[speedyman]

I'm not sure if I had the pushrods in correctly or not.

I did not wait for the rear lifters to bleed down. I torqued the rear rocker plate and then rotated the motor to do the front.

[Powerglides]

Oops. Bent valve(s) appear likely.

[speedyman]

Oops. Bent valve(s) appear likely.

That is the problem-bent exhaust valve. There was valve to valve contact. There is about a .020 gap on the exhaust valve seat in the center of combustion chamber. Still not sure if I had the pushrods reversed or if I had a pushrod not seated in its respective cup. I talked it over with Scott at Hillside Cycle. Head is being UPS'd to them for repair.

[attachment removed after 60 days by system]

[speedyman]

Oops. Bent valve(s) appear likely.

I do remember when I had the rear cylinder rocker plate torqued down and immediately turned the rear wheel to get on base circles for the front cylinder I had a good amout of resistance at one point. Maybe that was the point where the valves contacted each other. It looked as if the larger intake valve won the battle.

[joe_lyons]

Sorry to hear about that man. Hope you get everything fixed and get her all put back together soon.