150 Crossflow Exhaust Cover Water Leak

[skimmabird]

A couple months ago I noticed small leak around a couple of the starboard exhaust cover bolts. It drips about 2 drops every 3 seconds idling at the dock, and drips about every second on muffs. The leak hasn't gotten any worse. Should I assume on doing just the outer gasket? Do I need to do the inner gasket also? Also the bolts look like they're 1/4-20 and some are in bad shape, should I expect some to snap pretty easily? Any reason I couldn't put a mapp gas torch to some? Any help is appreciated.

Thanks

 

[Bob_VT]

Re: 150 Crossflow Exhaust Cover Water Leak

Be very very careful using mapp gas or any torch since aluminum melts at around 1200 and mapp can get up to 5000 degrees.

My suggestion is buy the head gaskets and the water jacket gaskets. Remove the heads if you are concerned the bolts might break and soak the entire head in oil or brake fluid for 24+ hours then remove the jacket bolts. If you should shear a bolt it will be easier to remove the broken bolt with the head off anyway.

If you want to use heat...... I would stick with propane (which still gets too hot) and use it very carefully.

Those bolts are all stainless steel too.

 

[skimmabird]

Re: 150 Crossflow Exhaust Cover Water Leak

The motor just had recent head gaskets and diverters. You can sneak the exhaust cover off with the heads on, assuming I do not have to futz with to many snapped bolts though right?

 

[emdsapmgr]

Re: 150 Crossflow Exhaust Cover Water Leak

Those exhaust cover bolts can loosen with age. They are installed with not much torque. (5-7 ft lbs.) Hopefully they will come off without breaking. You'll want to replace both cover gaskets. Should not be a difficult task on that flatback model. On that engine, both gaskets (inner/outer) are the same part number. Good thing to retorque those bolts after the engine has gone through 2-3 heat/cool cycles. You'll want to use a typical gasket sealer on the gaskets. Once the covers are removed you can visually inspect to see if any water was getting into the exhaust chest area.