Apex leakdown help PLEASE!!!

[SRXSRULE]

Ok, just doing some routine mait on my 06 Apex with 7,000 miles on it.

Leakdown test was 2%, 4%, 2%, AND 30%. Big problem for sure. I removed the exhaust and throttle bodies. Its leaking out the intake valves. It appears to be all out of one valve. The sled has been sitting since last winter. Looking from the intake side of the head the intake runner all looks clean, No signs of any burn marks around the valve seat.

So my options are a burnt valve/seat, Bent valve, or carbon stuck on the seat/valve. The intake runners are spotless but the piston tops and spark plugs do have a fair amount of carbon on them.

I thought I could remove the valve cover while doing the leakdown test and try and tap on the head of that lifter valve but its very tight to try and get anything down in there.

Before I pull the enigne I think I will spray the valve down with some good top end cleaner, let it sit for a while and then try to blow that out with a blow gun.

Any advise or "been there, done that" would be much appreciated! Thanks Eric

 

[summitboy]

If your valves are closed for sure 100% during the test then you can try your idea. If it doesnt work then just pull the head and inspect. Not to hard to do especially if you have the valve cover off already. Are you sure the motor isnt turning a little when you add the air to the cyl ? I had to hold mine on one of the cyl test because the pressure actually would turn the engine a little. Might just need to clean a seat up im guessing. Let us know what you find.

 

[SRXSRULE]

Ive retested that clyinder several times. No the piston is not moving and I can see the cam lobe is not close to trying to open the valve.

I sprayed lube down on top of the valve head and there is only one intake valve leaking. I poured a little top end cleaner down on the valves then turned it over several times and now its soaking.

After doing some searching over on TY I found some post about guys have rust issues on intake valves after sitting over the summer. My sled has sat for over 8 months now but my shop is heated/cooled year round.

If this dont work I will pull the head. Any tips for the timing chain/tensioner/alignment marks. Thanks Eric

 

[geno]

dirty valve

I have seen that before. In my case it was a little carbon/debris on the seat and face of the valve. And like mentioned, it was from that valve open, during the summer.

A little engine top end cleaner, or maybe some seafoam, should clean it right up. Get the engine hot and use it for a few hours.

I wouldn't take it apart, unless it was like that after a tank of gas, or got worse.

 

[gunnerthesnowman]

I have seen that before. In my case it was a little carbon/debris on the seat and face of the valve. And like mentioned, it was from that valve open, during the summer.

A little engine top end cleaner, or maybe some seafoam, should clean it right up. Get the engine hot and use it for a few hours.

I wouldn't take it apart, unless it was like that after a tank of gas, or got worse.

Happens a lot after sitting for awhile , should burn out once you get it under some boost , just warming it up ( no boost ) is not enough .

 

[philsummers21]

another old school thing that works well to clean up engines is add a little bit of ATF to the fuel. Don't take much.

 

[SRXSRULE]

UPDATE: Its Fixed!

Sled is not in running condition so i could not run the engine. With throttle bodies removed I preheated the head and valves, then poured some warmed up yamaha ring free down on the valves and rotated engine a few times then poured more ring free on the valve head. Let set for 90 minutes. Open valve, blow off with compressed air, crank engine.

Re-test leakdown= 2%

Thanks for the info. Eric

 

[thinksnow]

Is there someplace to read up on how to do this test? I have never done one before and maybe I should.

On startup, my '06 smokes fairly bad. After it warms up it is OK.