I got BB351 kit and tried to install it. All screws been tightened to specs (or nearly). Why nearly - I broke previous head at cam chain duct coz screws broke seats never reaching spec torque. I assume due to the presence of oil. I do have decent torque wrench. I got new head and after installation main screws come at 40nm at moderate speed rotation. Not slow neither fast. After test riding of 1 or 2 km just around the block I discovered that all coolant gone from the radiator to the rear canister and tail of the bike is wet. I assume that it happened due to the leak in the head gasket. It could be due to my overcautiousness torquing the head bolts (under tightened) or something else. Now the question -
should I tighten more the main bolts and see what happens or open the head and inspect it? I inspected gasket before installation and it was fine. Should I change it if there was a leak anyway? I sent email to Bill but he never replied. Probably I must call him and seek advice but I dont have his phone number. Please who installed the kit - share the experience. Thanks!

 

If the head bolts are under torqued, there is insufficient clamping force to correctly crush the head gasket. You'll have to disassemble and install a new gasket. Did you lube the head bolts & washers to help the bolts yield?

 

alex, no disrespect is intended by my statement whatsoever, but based on what I'm hearing in your post here, I'd suggest you seek out a friend/acquaintance who has some good mechanical knowledge to help walk you through this issue or find a trustworthy shop in your area to do the job. If money is no object, then perhaps it won't hurt for this to continue to be a learning experience as you go through the process. But it sounds to me like this may getting very expensive and may continue to get more so as you work on the bike. That's intended only as friendly advice from a fellow dirt biker.

As to the question about retightening your head bolts, klx4me is correct in suggesting that you start over with a new gasket. Plus, it sounds like you had an extreme overheat on startup, and I wouldn't run that engine again without pulling the cylinder too and inspecting the cylinder walls, piston, rings, etc.

 

Thanks for advice! Can I use standard head gasket? Yes I lubed head bolts. No it is not first engine that I am working on. However it is first for me which made of alloy

 

btw TNC I am not offended - you are right. However I will try to fix it by myself.

 

I would think you'd want to order another head gasket from Bill as I understand these are a special order item made just for the 351.

 

Yes, no intention to try to rag on you in your efforts here. No, you can't use a stock gasket because the bore size is very dramatically different between the 250 and 351. That comment is one reason I made those suggestions in my post above. I realize you may have worked on some engines, but you're working with an aftermarket setup where things have been "altered" to a decently large degree. Some of the stock parts just won't work any more. You need to get a new base and head gasket and any other small attendant pieces and pull that cylinder off to clean and inspect everything. Don't just throw a head gasket at it.

 

Thanks guys. Practically you confirmed my thoughts. Do you have web address of Bill shop? I cant find it anymore.

 

Bills bandbcyclerestoration.com click here Home Page

Best of luck with it.