Evinrude V4 hop up

[Hemi4Me]

Hey yall,

Hi, new to the site, been here many of time looking but never posted. Just picked up a motor for my little Checkmate, for the best price- free! I got a 1979 Evinrude 85hp V4, that I got just for removing and disposing of a boat out of the neighbor's yard. I have hardly no money in this engine, just my time and the price of a few tune up parts, and it sounds good for sitting for 8 years. Anyways, my little checkie is rated for 100hp, and I'd like to get some more from this engine. Done a little of reading, and it seems that I can bolt on some parts from a 140hp v4 for easy horsepower, how much hp can I get and what can I do with just bolt on parts for this engine?

[Riverman]

Bolt-ons will make a little bit of difference, but power will surely be limited with the 85 hp block - the ports are much smaller and the port timing is quite a bit milder.

Bolt-ons for that engine are limited to larger carbs from a 115 or 140, and some tighter heads. The 140 exhaust can be added but you will need to find some exhaust filler blocks (NLA) and have someone mill out a slot in the back of the block.

You'd be better off sprucing up that motor, selling it then look for a 140. It will be cheaper in the long run.

[hsbob]

thats about right as far as best $$$ for hp. i moded the 115 and got good results. but if you have to port which is required it will cost.

what year checkmate do you have. does it still fall of the pad when you make a corner with a skiier??

[Hemi4Me]

Cool, thanks for the input. Should I shave the heads, or find some to bolt on? I think I've think I got a blown donor engine. I just gotta check the yard. The boat is a 75 V-mate 1. I've never run it before, came without an engine, it originally had a fifty Merc on it. I figure that I'd start with this, and see how it runs, never had a checkmate before. Looks like fun, wanna get it in the water for summer.

[chynewalkr]

if you can get all the 140 or 115 parts for cheap or free then it would be worth trying out. dont bother porting it, and dont cut the heads, look for production heads.

there is plenty of threads on hopping up v4s, do a search on crossflow or v4.

work on your setup too, i gained more mpg from setup more than engine mods. use the search function to find others with similar checkmates and ask them about their engine height, props, jackplate ect.....

[EMDSAPMGR]

For bolt on hp, the older 140 carbs are a good idea. The 95-96 Crossflow 115 carbs will work just as well and they already have the fuel primer system on them. Anyway, make sure they are the 1 5/16" bore. I'd also look for some 79 140 heads (322864, 865)-preferable to milling. A set 4 of intake filler blocks, 322865 (NLA)-there are many still around. I like the composite reeds for idling and midrange. If you want to get into machining, you can tear down the engine and square off the ports. If you really want the bubble back exhaust, the 392000 exhaust filler block kit is probably still available and may be adaptable to your block. You would need to buy both the inner and outer exhaust manifolds. I doubt that adding the bubble back exhaust work will buy you much since your block doesn't have the 140 porting. Overfueling: If you just add the carbs, you may find that the stock 1 5/16" carb mains may overfuel and they may need to be rejetted. If you also add the heads, I'd run the stock 1 5/16" jets.