What size exhaust risers

[dgopetactical]

88 mercruiser 5.7 alpha 1 sn#b740551

I want to put new exhaust manifolds and risers on in a few weeks when my boating season is over. I am priceing out the parts and I see 3" or 4" risers does anybody know what I need. I dont want to take things apart now to measure and want to order asap. I know where im buying them from, I just need some info on sizing.

thanks

 

[Don S]

Re: What size exhaust risers

Measure the diameter of the hose coming off your present risers.

 

[Zackman]

Re: What size exhaust risers

The risers go between the manifold and elbows and are not on every engine. The risers are used to ensure the exhaust is high enough to help prevent water inversion. If you have risers, you should have no problem measuring them.

 

[Don S]

Re: What size exhaust risers

The risers go between the manifold and elbows and are not on every engine. The risers are used to ensure the exhaust is high enough to help prevent water inversion. If you have risers, you should have no problem measuring them.

99% of the time, when risers are mentioned, it's the same thing as elbows.
What you are refering to is an extension, and come in heights of 3 and 6 inches.

 

[dgopetactical]

Re: What size exhaust risers

I did mean exhaust elbows. Alot of part sites call them Risers also and that made me little confused. After a little research last night I found out they are 4" elbows. I went to mercury marine and got the part number for the parts from a cross reference of serial # from my engine ( mercury part 3807988A2) I then went to other sites and cross referenced again (since mercury marine did not state what size the were). then I figured out what after market I need. 4" elbows 7 degree.

I will take another look at mine just to make sure things werent changed by another owner. Thanks for your help