i am a new member that is in need of some advice. i have a head gasket leak on my 1998 ultra classic 1340 efi i am on a very tight budget with the wife (it took me 23 years to get this bike) i have had it only 2 months and it needs work already. she is not a happy camper. i am waiting on a stator at the moment and figured while it was somewhat apart i might as well fix the head gasket leak (getting oil on the fins). the hd stealer has a gasket set for $94 he recommended i get the set because it includes the base gasket o-ring? he said if i am taking off the heads it will release the pressure off the o-ring and if it is not replaced i may have a leak problem there. which means the jugs have to come off! i have never known a motor to be put back together using the same pistons and rings! he says it shouldnt be a problem. is he correct? has anyone done this without "rebuilding the motor"

 

Yep....PLENTY of times. I have had some EVO's apart with 50K on them and found the cross-hatch not even worn out of the cylinders. Of course...look at them good while you're in there. If you have to have them bored....that is going to be costly. Takes a special jig-fixture to have it done right. If it's running fine now and there is no evidence of high oil consupmtion or smoke....you may be just fine. Be sure to go ahead and replace the base gaskets like the dealer said. You're that far down in there....go ahead and do that.

Sounds like you need a break.

 

I think I would go the extra mile.You don't say how many miles are on the bike but being a 1998 it may be time to think of a couple of other things.Things like freshening up the cylinder heads,new rings,or even boring the cylinders.Theres no use in pulling all down just to do it again a short time later.I know what its like to be on a tight budget,I think most Harley guys have had to decide weather to buy parts or eat,I have.Like 1550VT said sometimes you pull a EVO down and they don't need much,but sometimes they do.

 

If you are careful, you can pull the heads and leave the cylniders alone and just replace the head gasket and the o-ring at the oil return passages. I am not an Evo guy but IIRC, those cylinder sit on a base gasket, not an o-ring. Be careful removing the heads and do not disturb the cylinder to case connection. Once the heads have been removed, get some copper tubing or some other small diameter piping to use as a spacer between the cylinder surface and the head bolts and screw on the head bolts on tight enough to keep the cylinder in place until you reinstall the heads.

You can purchase a pair of .030" Cometic MLS head gaskets for about $40; don't know what the o-rings cost but they are cheap. Clean up the heads as best you can and reinstall, again, carefully and retorque per the service manual. You didn't say how many miles on the clock but, being a 19989 model probably quite a few. No guarantees that the base gasket won't leak in the future but I have done this with TCs that do use an o-ring and not experienced leaks.

Of course the best way to get at this problem is to pull the heads and cylinders, check piston to cylinder clearance to see if in spec and if so, hone cylinder to break the glaze, install new rings, new Cometic MLS base gasket ($25/pair), new rings for stock bore size, new .030" Cometic MLS head gasket and ride on. If finances won't allow that, you go nothing to lose by trying the first/cheapest way out except the time a do over would take. You can resuse the Cometic gaskets, they are MLS (mulit layered steel) and don't compress much.

Or you could split the difference and pull heads and cylinders and forego honing cylinders and new rings and just replace both head/base gaskets. Just keep everything really clean during tear down and reassembly. This would depend entirely on what you see when you look at the condition of the cylinders.

BTW the .030" head gasket is a little thinner that the stock and will boost compression a point or two and tighten up squish for more efficient combuation. Good luck.

 

thanks guys. the motor has 55,000 miles. i know its a lot. but it runs great! no smoke or high oil consumption. if it were not for the leak i wouldnt even consider doing anything.

 

You sure it's not leaking at tha rocker box? I would check the compression before I pulled the heads. 55,000 is not a lot for a evo. That would not be uncommon for for that motor to leak there.

 

A good suggestion and worth cleaning up the top end and really looking closely for the leak.

Compression check is another good idea as well as a leak down test. The compression test will tell you the general condition of the cylinders/pistons and a leak down test should confirm if the head gasket really is leaking.

I should have metioned those in my first post; my bad.

 

its definatly the cylander head. occasionally i can feel a puff of air coming from the side of the cylander when first starting the bike.

 

Well, at least you have options and know what to do.

 

If that thing is leaking and you feel a puff coming from there I still wonder if its not the rocker box gasket. Could be internal case pressure.
You blow a head gasket enough to feel the blow its going to eat a hole out of that area pretty quick. We're talking 1400 degrees and a lot of pressure.