Hey guys I'm working on a 08 night train. We built a FM 107 for it a few months ago. The bike runs amazing but after 1300 miles we're seeing seepage from both cylinder bases. I know this is a common problem but this is the first time I've experienced this on an engine I built. Anyway my point of this post is do any of you guys have any advice on what I can do to avoid this in the future? I've ordered a new gasket set and will start tear down on this one tomorrow probably. FM mentioned using hylomar on the base. Anyone tried this before? I'm not sure I understand exactly what he meant so curious if anyone's tried this or if you guys have any other fixes. Thanks for any advice you guys can give.

 

We generally use a very light film of Hylomar on the cylinder base along with an OEM Harley O-ring. Please give us a call back and I can get you with Keith and he can explain everything. We can also get you setup with the necessary gaskets and O-rings.

 

I have used Three Bond 1194 to seal the cylinder/case joint in cases that were bored for larger pistons where the o-ring groove removed and no base gaskets with no leaks.

 

I think it was Bob that I talked to. He was very helpful and even gave me the hylomar part number you guys use. I also ordered the gasket set during the same phone call. Everything he said made sense until we hung up and about 5 minutes later my mind said "wait a minute" lol. I think I got it though. Just need to see it in front of me again and I'm sure it'll all make sense. Thanks

 

ide really check cylinder base/case for any abnormalities.no reason a TC should leak or need any sealant

 

I agree, if the mating surfaces are free of imperfections, heads are torqued properly and the studs aren't pulled there should be no need for anything other than the stock "o" ring. Inspect well

 

Will do guys thanks. The bike only has around 13000 miles on it. No leaks before the build and we're using the IC cylinders on it. Hopefully if we made a mistake somewhere or if there's an imperfection we'll find it. What also made me wonder is it didn't come from any one area. It seems to be seeping pretty evenly around both bases

 

When you get it apart give us a call, we certainly want to assist in determining what may have caused the leak.

 

Thanks I will. Just curious if you know what the final torque should be for head bolts? We followed the book to the letter and the last torque sequence goes 15-17ft/lbs then an additional 90*. I just checked the torque and they're at about 40-45ft/lbs before the bolt starts to move.

 

Absolutely.
Not a normal occurance, and that ancient Rolls-Royce engine sealer is not the cure.
The cylinder bases may not be perpendicular to the bore, or as Kirby has mentioned, some other oddity or flaw.
Scott