minimum compression required 60hp 3cyl

[ejlydic]

Just a quick question. I have a 1986 60hp Evinrude VRO engine. It's in the shop now because of idle problems. The mechanic tells me he's brought the engine back to factory settings and the motor will not idle due to low compression. I'm told that the cylinders register 130, 130, 125 in a compression test. Due to the low cylinder compression the vacuum is not strong enough for proper fuel quanity required to idle properly. I had a 35hp Evinrude that ran fine with similar readings. Are these readings just to low for a 60hp?

Thanks.

Ed

 

[Texasmark]

Re: minimum compression required 60hp 3cyl

Better grab your engine and run. Those are great numbers and are within 5 psig of each other.

Merc doesn't publish actual numbers due to variances in lube on the cylinder walls but any engine that won't run on 130 psig won't run for some other reason. They do however, indicate that the cylinders should be within 15 psig. That's higher than I am used to (10 psig), but that's what the manual says.

I solved idle problems on my Merc with a $6 can of Sea Foam.

Good luck.

Mark

 

[AlanR]

Re: minimum compression required 60hp 3cyl

Like tex said, pick up your motor and run as far away as you can. I had a 1980's Johnson 115 run on 80 psi - 70 psi and she still ran arlight. Did he clean the carb? Id say dirty carb or reed's not sucking gas OR theres a bad gasket some where on the motor thats sucking air in

 

[VADER8674]

Re: minimum compression required 60hp 3cyl

i agree dirty carbs

 

[tashasdaddy]

Re: minimum compression required 60hp 3cyl

run, find another mech. hang out at the ramp, talk to people and see who they use. especially the guys with the older engines.

 

[Theoutdoorsman]

Re: minimum compression required 60hp 3cyl

Better yet.......... Spend your next $100 on an OEM Parts and Service Manual and let the good folks here at iboats assist you with any questions you might have regarding the upkeep of your current outboard. This way, you KNOW what's been done to your engine and won't have to rely on shadey mechanics who suck your wallet dry. You'll get your money back the first time you open the books!!!! Best of luck to ya..................... ALAN

 

[ejlydic]

Re: minimum compression required 60hp 3cyl

Thanks for all the input. The mechanic called on Friday to ask if I wanted him open it up and check the pistons and rings. Sounds like I make the right call by telling him to rebuild the carbs first. Lets see what I hear next week. I may be looking for that service manual and some help for you'all

Ed

 

[Texasmark]

Re: minimum compression required 60hp 3cyl

Hey Alan, what kind of mean machine do you have a picture of there? Looks awsome.

Mark

 

[rodbolt]

Re: minimum compression required 60hp 3cyl

after that your STILL gonna let a shade tree sucker work on it?
makes me wonder who the sucker is.

 

[AlanR]

Re: minimum compression required 60hp 3cyl

O the motor in my avatar is my johnson v8 3.6 gt. Pic was taken before I sold it d

 

[ejlydic]

Re: minimum compression required 60hp 3cyl

after that your STILL gonna let a shade tree sucker work on it?
makes me wonder who the sucker is.

My family has been doing business with this boat shop as long as I can remember. I'll give them the benefit of the doubt. When I'm completly satisfied this particular mechanic is indeed being shady I'll bring it up to the owner and have a discusion!

I came here for input not insuts! Thanks for your constructive criticisms!

 

[DHPMARINE]

Re: minimum compression required 60hp 3cyl

Sorry you feel insulted.I enjoy this forum and all the questions as well as the answers.It also upsets me when someone seems to dust us off as you have.

Your compression readings (130,130,125) are great and have not a thing to do with an idle problem.

You did ask for advice and we rendered it.

DHP

 

[ejlydic]

Re: minimum compression required 60hp 3cyl

I appoligize that my reponse seems to be adress to all. This forum has been suggested by several people as being "THE" place to get advice on outboard maintenance.

It was Rodbolts reply that hit a nerve since this was my first post and I'm known by no one. Perhaps the way I structured my question brought on the reponse. Perhaps I need to be a little more thick skinned.

Ed L.

Ed L.

 

[rodbolt]

Re: minimum compression required 60hp 3cyl

cant help your thin skin, you asked and all I can do is wonder,
I ment no offense but I see shade trees on a daily basis.
but I will stick to my guns, either the info posted is faulty or the tech was/is gonna get a new pair of shoes from your boat.
one day I may write a book about customers, the second time, and shade trees that tear up more than they fix.

wish I had a dollar for every motor I hve tested that was blown up and the customer says no way it was just rebuilt by Rusty Bolt Bob and his can of Krylon. they will spend 100 dollars to have painted junk.
happens all summer long here.

I dont trust poken hope techs.

 

[Theoutdoorsman]

Re: minimum compression required 60hp 3cyl

Hey Texasmark......... Not sure which "Alan" you were referring to, but mine's a 1979 Evinrude 140 and I'm in the process of getting her going again......... Still looking for some answers if anyone can offer some insight. The link to my thread is.........


http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1154309


Sure look forward to picking some of your brains......... d ............ My handle on the board is "Theoutdoorsman". Sorry to tap into your thread. It is kind of rude and I appologize.

 

[AlanR]

Re: minimum compression required 60hp 3cyl

LOL to many Alans d

 

[Texasmark]

Re: minimum compression required 60hp 3cyl

I saw your pic but AlanR's pic got my attention. That sucker must be one fast dude.

What's the pitch on that prop, about 40?

Sad note on racing, saw a film on a hydro trying to break his 200 (I think) mph speed record. Got to going so fast that the boat took off like an airplane, kinda hung there in the air and then flipped over backwards and came crashing down. Needless to say he didn't make it.

Mark