exhaust and mixing elbows (again)

[KEN MATEJKA]

I have removed my exhaust and mixing elbows on my 2gm20f and have puchased new ones as well as the coupling "nut" as all were severely corroded(mixing elbow in best shape). Has anyone tried some type of exhaust sealant on the threaded parts or is this needed at all. Also, has anyone tried some type of anti-seizing compound to facilitate disassembly as I had to use a pipe wrench and a 6 foot cheater bar to get them apart. The yanmar book mentions nothing of the reassembly and I wonder if any of these compounds would help.  Also, I was able to get basically all of the soot/coke build up out of my old mixer elbow by soaking in a 50:50 mix of muriatic acid and water for 15 minutes. Before this I could not blow through water in nipple. Now the water and exhaust portions are wide open. I am keeping this as an emergency/short term replacement.

 

[Steve Dion]

You should use some never sieze.

Ken:You should use some never sieze on the threads. I think you should be able to get this at any automotive store. They use this stuff on exhaust parts in automobiles whenever that take that stuff apart.I do not know how much help it's going to be when you do it again in 3-5 years, but it cannot hurt.When we took ours apart, we used a torch to heat up the parts. This helped but we still needed a breaker bar. Ours had only been in fresh water and it was very rusted together.

 

[Sam Lust]

Never seizes

Steve's right - He watched the professional he hired to do the exhaust use it.Never seize is graphite in a high temp grease base. I use it on ALL (Count them- ALL) threaded fasteners. Screws into the mast, nuts onto bolts, all hardware on the Yanmar. All threaded surfaces of bronze shaft logs. Before I dropped the engine into the boat I even did the bolts that hold on the gear (transmission) Want to save some aggravation? Coat the threads on spark plugs before running them into your outboard. They won't stick. I even do the bases of some light bulbs.

 

[Ken]

Ceramic

Ceramic coatings will prolong the life of the elbow. It's common in auto racing to coat the exaust system. The elbow cleans up easier and the coating prevents build up. It runs around $100 for an elbow this size. Heard this trick from a power boater. Kept his system clean for over 10 years.