1980 85 HP evinrude are these the correct carbs?

[SparkieBoat]

I know that I have been wearing the forum out lately, but I did some horse trading and just now kinda figured out what I got. Apparently the previous owner had a 1984 140HP johunson, something must have went bad inside the block, I have not checked it out yet but he put a 1980 85HP powerhead onto the 140 midsection. It also appears as though he may have swapped the parts from the 140 like the flywheel, stator, starter ect. onto the 85hp head. I am wondering if he swapped the carbs and if so how would 140 carbs run on an 85hp and how can I tell which carbs I have? thanks a lot.

 

[racerone]

Is there a size on the bottom front of the carburetors ?

 

[Chinewalker]

Yep, on the front of each carb should be a measurement number. That is the venturi bore size. 140 would have 1-5/16". 85 would likely have 1-1/8", maybe 1-3/16".

 

[emdsapmgr]

The size of the carb throat is the number cast into the front flange of each carb. Such as 1 3/8". If I were wishing, I'd hope that the other guy transferred these items from the 140 to my 85: Carbs (only if they are 1 5/16"), heads, rubber intake filler blocks. All will bolt on. All will add hp. If the 140 carbs are the 1 3/8" size I would not use them-just too much air/fuel for that block. Electronics are basically the same. There will be some carb variation in these early years. The 79/earlier carbs had actual choke butterflys, the 1980/later carbs did not have them. (they had the fuel primer system) While the carbs will interchange, you'll have to adapt for the variations in the choke systems if you want it to start when cold.

 

[SparkieBoat]

Thanks a lot guys. that is some very valuable info. Would putting the bubble back exhaust housing from the 140 onto my 85 HP motor help it out? also would the intake from the 140 be helpful to that 85 with the 1 3/16 carbs?
checked out my carbs, 1 3/16 and it was hard to read, I thought it was 3/8 at first, had to get a magnifying glass. with 56C main jets. butterfly choke.

 

[emdsapmgr]

The carbs you have on it are typical for an 85/90 hp engine. Late in the 1980 production year, the 85 carbs came with 58c main jets on 1 3/16" carbs. Look for a set of 1 5/16" carbs. Used on the 140 and later 115 blocks. The intake manifold is the same part number between an 85 hp and 140 in 1979. Swapping it will gain you nothing. To install the bubble back exhaust, you'll have to transfer the exhaust filler blocks, then have the exhaust machined flat to accept the exhaust manifolds. That means a complete teardown and some expense. A lot of work for a few hp. Don't forget that the intake and exhaust ports on that block are small. Consider widening those ports to get the block to breathe more like a 115 block. That means a complete teardown for sure. The rubber intake filler blocks will buy you 3-5 hp.

 

[SparkieBoat]

thanks a lot.. I do not want to do a teardown for sure. So I will leave it like it is, i am going to be selling it anyway. I did find a guy about 3 hours from me that has an early 80s 140 in good shape for $800. once I sell this motor I may go buy that one if it is still available.