140hp out of a 115 evinrude

[kilburna]

My 140 got stolden(along with my boat & trailer) now I have a 115, I really want the performance My 140 had. I know the carbs & exhaust are differant.I have 140 carbs & am looking for the exhaust manifold.Some people I know guess the intake are the same on both engines,some say the reeds are differant. The intake the carbs came off of is for sale,but do I need it? & do you know where I can but the exhaust manifold?
thanks Kilburn

 

[ezeke]

Re: 140hp out of a 115 evinrude

Depends on the model years. The 1979 140 crossflow is about the same as the 115 crossflow after they re-rated them around 1985.

If you have the flatback exhaust, you would need to modify the block at least some to hold the filler blocks for the bubbleback, unless you leave out the filler blocks. (The flatbacks are not tapped for the screws to hold the filler blocks).

Your best bets for the bubbleback parts are to keep a search on ebay, contact salvage yards, or buy a parts engine.

Getting the bubbleback parts new will cost you.

Switching to the 140 carburetors will probably give you at least the performance difference that you expect, but it will be in the high end.

The 140 intake manifolds usually had the rubber filler blocks.

 

[emdsapmgr]

Re: 140hp out of a 115 evinrude

The exhaust filler block kit to make a bubble back exhaust system is available from Bombardier under part number 392000-about $ 175. Double check the exhaust chest on your 115 to make sure it has the bosses for mounting the filler blocks. The 140 crossflows also had high compression heads. Probably NLA now, so you will have to find a used set. Consider adding a set of composite reeds. They idle well and improve midrange pickup.

 

[kilburna]

Re: 140hp out of a 115 evinrude

Thanks for thr replies, my 115 is a 86 or 87 & the carbs came off a 82. Should I buy the 82 intake or just put the composite reeds on the 115 intake that I have?

 

[ezeke]

Re: 140hp out of a 115 evinrude

The 115 in 1986 and 1987 would have been a bubbleback, and if you look at the throats of the carburetors, I think that you should find them to be the same as the ones on a 140 from 1982. I doubt if that is the correct year.

What are the numbers on the welch plug on your engine block? (Top of starboard cylinder bank)

 

[Faztbullet]

Re: 140hp out of a 115 evinrude

Just a note, if new filler blocks are added they will have to be machined flat with the rear of the block and the block will need exhaust divider cut.

 

[emdsapmgr]

Re: 140hp out of a 115 evinrude

You should be able to use the 115 intake that you have. OMC made all the V4 intakes the same across the hp range.

 

[kilburna]

Re: 140hp out of a 115 evinrude

Thanks guys
I will keep my intake and check on the composite reeds.


Kilburn