Hi,

I just had a local shop replace my rocker box gaskets. When I picked the bike up, I was told that my head gaskets were leaking and needed to be replaced. to show me, the mechanic sprayed brake cleaner on the area at the head gasket while the motor was running and the motor did sputter, leading me to believe that there was indeed a leak in the head gasket.

The bike runs like a champ. Just took it for a 200 mile ride to Anacortes, WA for the Oyster run the other day. I sprayed a small amount of water on the same area myself and the motor did not change its idle at all.

Is there a best way to check to see if my head gaskets are leaking? compression test?

thanks

andy

 

- when the mechanic sprayed the engine , was the engine up to temp ?

- that's important.

- and imho , if she's running good , leave her well alone.

.

 

Maybe it is an intake leak?

 

Compression test or leak-down test and the recommended way is with engine warm.

From personal experience - what can happen, when spraying any type of fluid around the engine area, is that the mist will often get pulled into the engine thru the air cleaner and cause a sputter.

If a head gasket was leaking so bad as to pull air in, on the intake stroke, you'd hear it LOUD on the compression stroke and doubtful it would even fire at all. And since it's not spitting thru the intake, doubtful the intake gaskets are leaking.

 

Flammable liquid on a running bike? Haven't they heard of compression or leakdown tests? What did the shop voodoo medicine man say about it? LOL If it is running well, leave it alone! A leaking head gasket would be obvious in performance (low compression, high oil usage). Both kits are inexpensive to buy and come with instructions (and in Chapt. #3 of SM) if you want to DIY.

 

lankester,

A compression or leakdown test at the shop then and there would have save you the pain later. A head gasket leak in Evos are not as common as Shovels. A quick spray of WD40 around intake manifold, heads is a quick check to see if you do have a leak, because your engine rpm will go up, but it's not definitive as the two checks mentioned above. Depending on $$, you can run it for a while because you just had the cover gakets replaced. What you will notice is worse gas mileage and some smoking.

If you have a compression test kit. You can do that test easy enough. Remember to have your throttle fully open. Results should be no greater than 15% difference in each cylinder.

BTW, what year, model, mileage, etc...so we can get a better idea.

ltc n

 

Thanks guys!

Unit is a 1998 roadking with evo and EFI. 32,000 miles.

There is no abnormal sounds eminating from the motor and it runs smooth. Some smoke however when I was in a border line-up and she got a little hot.

any idea of what the compression should read with those miles?

thanks again.

 

I've got 43k on mine... I noticed a "puff" when I cracked the throttle. Comming from the right side of the rear jug. Its clearly my head gasket... I got a bit paranoid and asked the guys here and at my Indy... The concensus was ride it and see how it does, along with the leakdown and compression suggestions.. At first, I was all about the later, more technical suggestions. But, after running it for a day or two and cracking the throtte several times when hot, its gone.. I must have just noticed it cold and got paranoid.. I'm gonna ride it till it gets worse..

 

If it's running good, I wouldn't worry about it. Same as base gasket oil leaks, if it's leakin'a bit of which it probably still has the paper gaskets, I wouldn't worry about it until it starts to get bad, then it's time to do something about it, until then ride it or deal with it when the weather is winter.

 

You could check it cold and warm and note the difference. Variation between the cylinders is the important thing to look for.

The "book" says 90 psi is acceptable, but that's weak in my opinion. 145 - 165 is "good to go" on stock compression pistons.

And as mentioned earlier; turning with the starter, both plugs removed and throttle locked in wide open position. Watch the gauge through 5 compression strokes (you'll feel it in the hose/gauge) and note the reading. Variation between the cylinders should not exceed 15%