Major air leaks

I have an 82 xj and I am having a problem with air leaking into my intakes. What I have done so far is rebuilt my carbs after I boiled and cleaned them, replaced my intakes on all four carbs, checked my valve adjustment and ran a compression test on all cylinders.
Now when I start it it will not idle and I have to have the enrichment (choke) on just so it will run. Runs great on high end but runs like crap on the low end. There is a major increase in RPM when I spray starting fluid on the intakes.
There is one thing that I don't know if I'm doing right and that is when putting on the intakes should I be using a gasket sealant along with a gasket between the cylinders and the intakes?
Also, I have replace the peacock with a standard one.

 

If you're getting big rpm increase when you spray on the manifold boots, that's TELLING you where at some of the leaks are..... If you don't have gaskets or rtv between them and the intake, there's a major leak. If you have cracks all the way through the boots, or big cracks at the opening where the carbs are inserted, there's air leaking there too

 

what kind of xj is it?
what parts did you add when you did the boil and clean?
did you strip the carbs down to individual components?

 

Throttle shaft seals in the carbs are always overlooked and forgotten. Replace them. If you boiled your carbs most likley the seals are shot.
You don't need any extra sealer on the gaskets for the carb boots if they are both new.

 

Normally not, but if the rpms shoot up when he sprays the intake boots, that pretty much tells where the leaking is. Even new boots won't always seal tight enough there.

Changing the petcock won't do this...

Did you sync the carbs yet?

Did you open the enricher and clean that whole circuit?

Sounds like carbs still have clogs OR some jets may have been installing the wrong holes.....

Hafta narrow things down a bit yet...

 

I had an air leak on one carb and when I removed the intake about 1/4 of the gasket was missing. I have no idea how that happened, but I had the same thing happen on my Toyota pickup truck. For my bike I simply made a gasket out of gasket material and it sealed nicely. You didn't say, but is it all of the intakes or just one?

 

My bike is an xj 650. When I cleaned the carbs I broke them down completely before I soaked them overnight in carb cleaner. I replaced everything in the carbs with the exception of the jets. I replace all four intakes using new gaskets and RTV on both sides. Yesterday I broke them down again and cleaned them and did a double check on the jets making sure they were installed right. I also replaced the throttle seals on all of the carbs. Found one of the seals to be in really bad shape. Sync the carbs (the best I could because I cant get it to run under 3000 rpm)
Started it back up and nothing changed, still will not run under 3000 rpm.
It feels like it is running out of gas because it will not accelerate under 3000 rpm but it runs strong over 3000 rpm.
When I had it running yesterday what I didn't do is spray it with starting fluid to check for leaks, but it still ran the same as before.
I checked the diaphragms and didn't see any light coming through them.
Do you think it might be a problem with the diaphragms?
Could it be an electrical problem?
Anybody interested in a parts bike?

/-=\- This is some of my hair that I have already pulled out!

 

First, check for the air leaks--I like to use propane.
From what I am reading the bike will try to run at idle but will die, not that it automatically revs to 3000. If that's the case and you eliminate the possibility of air leaks then I would recheck my bench sync and if that's ok then concentrate on the pilot system. The pilot system is the primary source of fuel at idle and up to approximately 1/4 throttle so if it's blocked the bike won't run unless you supply more fuel by opening the throttle or the enrichment circuit. If you decide to work on the pilot system use a spray can of carb cleaner and make sure you get a strong flow out of the jet and all the small channels. Also, make sure the o-rings, washer, spring are in properly and in good shape.

 

Make certain the throttle shaft linkage and the orientation of the the enrichment circuit spoons above the valves is correct.

Gary H.