Johnson 90 HP Exhaust Housing

[cxcantu]

I noticed one of the covers of the lower mount bracket was cracked and when I removed it I found that the Rubber Mount Assembly inside was dried and melted (turned to dust literally). What function does the Rubber Mount serve? And, any recommendations on how to remove the melted dried part from the housing so I can install a replacement?

 

[sutor623]

Re: Johnson 90 HP Exhaust Housing

This seals the exhaust. A leaky exhaust can give you an odd idle, and turn your lower unit black. A scraper and heat will get the old gasket out.

 

[emdsapmgr]

Re: Johnson 90 HP Exhaust Housing

Possible the midsection overheated due to missing exhaust seals in the lower unit, as sutor mentioned. That rubber mount is replaceable. Part # 391709. You can see how the part fits in the midsection on this factory parts website: epc.brp.com. If one is bad, you'll want to check the one on the other side too.