I'm trying to remove the front cylinder head and it's stuck to the cylinder even with Cometic MLS head gaskets. Any suggestions on how to separate the two? I tried leaving in the head bolts loose and hitting the head with a rubber hammer with no luck. There doesn't appear to be enough room to pull both off together.
No Hammer!
Have someone hold the cylinder to the case. Wiggle the head left to right pulling up. Possibly the dowel pins are in a bind.
Quote from: Ohio HD on June 05, 2022, 04:11:38 PMNo Hammer!
Have someone hold the cylinder to the case. Wiggle the head left to right pulling up. Possibly the dowel pins are in a bind.
We had tried that with no luck.
Quote from: BigT on June 05, 2022, 04:24:05 PMQuote from: Ohio HD on June 05, 2022, 04:11:38 PMNo Hammer!
Have someone hold the cylinder to the case. Wiggle the head left to right pulling up. Possibly the dowel pins are in a bind.
We had tried that with no luck.
Tell us what you tried, and we won't repeat it. :wink:
Reinstall the head bolts and back them off a turn. (The pushrods must still be in place.) Crank the engine over in short quick shots and let the engine compression do the work.
Quote from: kd on June 05, 2022, 04:30:47 PMReinstall the head bolts and back them off a turn. (The pushrods must still be in place.) Crank the engine over in short quick shots and let the engine compression do the work.
Well unfortunately that didn't work. I had to put the rockers back in and reinstall the pushrods. I did manage to make an oily mess as oil was pumping out the oil line that cools the head. I sure hope I don't have to pull the motor to pull the cylinder and head off together.
I had the exact same thing happen...heads stuck to the cylinders with MLS gaskets. I ended up breaking the corner of a fin off one of the heads by using the rubber hammer. Probably why Ohio said don't use a hammer??? I stuck a plastic pry bar in between the fins and patiently worked it apart. But as said, I did not come out of it without a bit of damage.
Just an idea... You can buy some rusty bolt spray at the auto parts store that is a freezing spray along with the penetrating oil that shoots out. Maybe trying some of this freezing might make the two parts release their grip. Sorry I don't have a better suggestion.
Make a jack. A tight fitting metal piece in between the fins that sticks out and make an adapter on the inlet port with a tab. Use a bolt, nut and sleeve to put pressure between the plates. Will take some fabrication but not too bad. I have backup or clamp plates I put between the fins for various machining operations and a copper one for welding. They work fine and spread the load.
Thanks guys for all of the replies. I went at it again today and was able to pry it apart using a tab that jogs out on the head. I did break a fin with a miss swing with the rubber hammer. Hopefully it's not to noticeable once assembled.
I have been trouble shooting an issue with the front cylinder only fouling plugs within a few miles. I couldn't tell if it was oil or fuel fouling. Leak down test showed 2% on rear and 6% front. I changed plugs, wires, tmap sensor with no luck. At a last resort I let the HD dealership troubleshoot it and $1,500 later they couldn't find the problem but did manage to replace perfectly good lifters and pushrods. I pulled the head and found a broken spring on one of the exhaust valves.
Luckily it didn't do any damage beside putting a dent in my wallet!
Hope you saved all the "GOOD" parts you took off chasing your problem. Bob
Quote from: BigT on June 06, 2022, 11:36:05 AMThanks guys for all of the replies. I went at it again today and was able to pry it apart using a tab that jogs out on the head. I did break a fin with a miss swing with the rubber hammer. Hopefully it's not to noticeable once assembled.
Just make sure you never mention it to your friends or anyone who looks at your bike, and if it's like my broken fin, no one will notice.
If it's any consolation thus is more common than many think on the m8
WHAT was holding the head to cylinder, gasket or dowel? Just curious for later :nix: reference.
Quote from: Breeze on June 07, 2022, 03:44:58 AMWHAT was holding the head to cylinder, gasket or dowel? Just curious for later :nix: reference.
It was the coating on the MLS gasket.
Big T, wondering if the gasket maker is aware?
we had one M8 engine that we could not separate the head off the cylinder no matter what we tried. We tried everything we could think of to separate them with no success. We ended up pulling the whole engine and then slid the head and cylinder off as one unit. Once we had the head/cylinder off we tried to separate them again and still could not get them apart. It's like they were welded together. The customer was going with a big bore kit and ended up getting another set of heads to go with his new big bore kit. We even tried to slam the cylinder/head down over a piece of firewood that fit inside the cylinder on the concrete floor to try to separate them...with no luck. The customer said he would use them as a lawn ornament. :nix:
That was the first time in my life that I couldn't get a head to come off of a cylinder.
No Cents, you make me feel REALLY lucky that I was finally able to get my heads off with just a broken fin. WOW!