1983 150hp Evinrude Rebuild or buy ?

[iwombat]

Re: 1983 150hp Evinrude Rebuild or buy ?

Agreed - that's a dead-ringer for a cylinder with a water intrusion issue.

 

[wilde1j]

Re: 1983 150hp Evinrude Rebuild or buy ?

What's a good shop manual for this motor I heard seloc was not a good book

Clymer is even worse. Get the OEM book

 

[sea1tech101]

Re: 1983 150hp Evinrude Rebuild or buy ?

Ok guys I'm thinking of changing the heads to get my compression upto 120psi along with changing the pistons and some other stuff. Here's my problem how can I find whats interchangeable and specs on the heads so I know what head to go to. I have seen some heads on ebay but I dont know whats the lastest year model I can go to and whats the biggest hp head I can put on (ex.175/185/225). thanks

 

[iwombat]

Re: 1983 150hp Evinrude Rebuild or buy ?

It would probably be cheaper to just have those heads decked. Any good machine shop can do that for you. Someone else will need to chime in to give you specifications on how much to shave off though.

 

[sea1tech101]

Re: 1983 150hp Evinrude Rebuild or buy ?

So I was wondering do we have an evinrude specialist on the boards. One that can tell me the specs of the heads that I have and the 185 and 200 heads. So I can determine how much to deck the heads that I have.

 

[emdsapmgr]

Re: 1983 150hp Evinrude Rebuild or buy ?

You may not find much compression improvement from working the bathtub heads you have on the engine currently. Try to find some high compression small bore 1978/79 235 heads. Part numbers 323872/873. Then it's just a bolt-on situation. Keep in mind with the higher compression, you will need some bigger bore carbs and jets to keep these heads cool. There is no need to change the pistons. Watch out for later 235 heads-the bore size changed and so did the part numbers.

 

[joe agey]

Re: 1983 150hp Evinrude Rebuild or buy ?

Hi I am working on the same motor. I need to know if anyone know what the exhaust cover bolts are to be torque to on the xp 150. And do I need to use gasket sealer on the exaust gaskets.
Joe

 

[richock]

Re: 1983 150hp Evinrude Rebuild or buy ?

all plugs were out. I tired decarbing it haven't rechecked the compression yet. but i took for a spin and no change 40mph at 4800rpm. can head be pulled without removing whole power head.

What's the WOT RPM supposed to be on that motor/ in that boat? 4800 sounds low maybe getting a prop to pull you rpm's up might give that old motor more speed.

 

[wilde1j]

Re: 1983 150hp Evinrude Rebuild or buy ?

That motor when running right and propped correctly should turn 5800 @ WOT.

 

[emdsapmgr]

Re: 1983 150hp Evinrude Rebuild or buy ?

You have original factory heads on that engine. 328324/325. They are low compression bathtub heads-large chambers. No matter how much you deck them you won't get much compression. You need to swap them out for a set of high compression early 235 small bore heads from 1978 to 1979. 323872/873. Those stock heads will get you up to around 120 lbs on a healthy powerhead. You'll need to feed them premium gas only and will probably need to swap out your stock carbs for some big bore carbs. Your small bore carbs on that 150 won't feed the powerhead the air/fuel it needs to make the hp you need. Having said all of that, any increase in hp on this powerhead will be moderate and won't get you anywhere the speed you are looking for. You will need to be tinkering with your engine setup and prop combinations also.

 

[joe agey]

Re: 1983 150hp Evinrude Rebuild or buy ?

ON the evinrude 150 the compression on that motor is around 90 to 100 psi I was check the compression on my engine and I thought the compression was low to but i found out that on that engine if the compression is about 10 percent of each other that the compression is ok . and on that motor there are six check valve behind the carbs. one of them could be stuck.
Joe

 

[tosoutherncars]

Re: 1983 150hp Evinrude Rebuild or buy ?

So, to recap; figure where the water is coming from, early 235 heads, bigger carbs, full tune-up, then prop for 5800 at WOT... What about an overbore? If you're rebuilding anyway, and keeping it for the long haul... I still see +.060 kits listed.

I dunno, if you're really not going to be happy with much less than 200HP, it seems to me it might be easier to do the HG, sell it on and buy a bigger engine. (Of course, that's exactly the kind of rational decision that I can never seem to make in real life...)

 

[Faztbullet]

Re: 1983 150hp Evinrude Rebuild or buy ?

I still see +.060 kits listed.

Oversize boring does not add hp to a 2 stroke ..

 

[tosoutherncars]

Re: 1983 150hp Evinrude Rebuild or buy ?

Oversize boring does not add hp to a 2 stroke ..

Well no... Greater displacement would give him more tq, allowing him to run more prop and getting him closer to the speeds he's looking for.

All of which kinda misses my point; that selling his existing engine and buying a bigger one would possibly be cheaper in the long run, and definitely a huge gain in time spent and headaches avoided. I guess it's a matter of choosing between wrenching or boating... (Not to say it's always an easy choice! I'm rebuilding a '65 for my kicker; but the $ equation is a bit different. $400 in purchase price and parts will get me an almost-new engine; a comparable 'late model' engine in my area would be $1000+... And I've got lots of time btwn now and next spring!)