350 mercrusier....260 - HP/ Exhaust riser gasket question?

[81 Checkmate]

1986 - Serial # B427596...350/260HP

I am fixing my thru hull exhaust mess..... with my fabricated switchable..... I had to add a 1" spacer between the riser and manifold to get a better angle and straighter shot out the back + get a better fit to my Y pipe.

I have 2 gasket sets.

1- with sloted holes on 4 sides
1- with sloted holes on two sides and 2 restrictor holes on the other sides

My plan is to put the 4 sloted on the manifold side and the 2 sloted between the riser and spacer with the restricor holes aft and fwd.....slots port and starboard.

Question - am i correct.

 

[81 Checkmate]

Re: 350 mercrusier....260 - HP/ Exhaust riser gasket question?

Any takers on the question?

Go with the 4 sloted gaskets top and bottom.... or the sloted on bottom with the restrictor hole type on the riser only.

 

[NHGuy]

Re: 350 mercrusier....260 - HP/ Exhaust riser gasket question?

Depends on which cooling system you have. Or, if you remember how they came apart, reassemble the 2 slotted gaskets as they were before.

 

[Don S]

Re: 350 mercrusier....260 - HP/ Exhaust riser gasket question?

View attachment 99_10 Exhaust Gaskets.pdf

 

[81 Checkmate]

Re: 350 mercrusier....260 - HP/ Exhaust riser gasket question?

Thanks Don for the bulletin... You must have a seperate server for all that info!

I think i have 4B.......if they are refering to the bypass as being the two hoses at the very top of the thermostat housing above the thermostat going to the elbows? Then thats what i have.

Gaskets with restrictor holes

 

[81 Checkmate]

Re: 350 mercrusier....260 - HP/ Exhaust riser gasket question?

Not to change the subject...but how in the heck do you get the thermostat outa the housing? Its stuck in there.

 

[81 Checkmate]

Re: 350 mercrusier....260 - HP/ Exhaust riser gasket question?

Update......
Got the thermostat out, had to use a big socket and knock it out...New 140 deg installed.

Completed the riser exhaust set - up........Sounds soooooooo....much better.