92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

[SparkieBoat]

I just purchased the above mentioned motor. the guy I got it from, buys old motors and rebuilds/fixes them and then resales. He supposedly did a complete rebuild on this motor. It has about 1 hour on it now. The compression is

1 102
2 90
3 95
4 89
5 100
6 86

I have read that is is normal to get up to 10 psi difference between the left and right bank, but most motors I have owned all had close to the same compression, I had a 96 60 degree 150 before, it was a GL (intruder) model and had about 110-115 on all. I am just wondering if I could expect the compression to even up some as I get more hours on the motor, or If I should consider pulling the heads and taking a look??? what would you do?

 

[Haffiman]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

I would have asked the guy what he had 'fixed' on the engine.
If a complete re-bore on all 6 and new pistons etc, I would stay away.

 

[bob johnson]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

I would have asked the guy what he had 'fixed' on the engine.
If a complete re-bore on all 6 and new pistons etc, I would stay away.

I wondering what the specific reason you have for saying that?

because you dont want a completely rebuilt motor...or because the numbers vary so much on a fresh rebuild??

bob

 

[j_k_bisson]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

If he rebuilt that (rings and hone job) then there is a high possiblity that there is something wrong there.

Are those numbers from a warmed up, just shut off motor? Or from a cold motor not run in a while?

It would be kind of hard for me to justify buying a motor that needs a rebuild, by those numbers one is required.....

 

[Faztbullet]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

Hey Bob ...See you emptied your pm box, shoot me that list again.
Hey Sparkie from readings it looks like a rering on worn pistons/cylinders...pull the heads ands inspect as this motor has o-rings ...

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

I will pull the heads, the numbers are from a warm block...thanks

 

[Haffiman]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

I wondering what the specific reason you have for saying that?

because you dont want a completely rebuilt motor...or because the numbers vary so much on a fresh rebuild??

bob

Below 95 on that engine on a re-bored and new pistons I would be slightly suspicious. However it may be due to cranking speed and the tester used. Then #3 cylinder looks 'suspicious'. However if just 'de-glazed' and reassembled without too much parts changed, you may be up for a surprise soon, again back to cyl #3.

 

[boobie]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

The numbers vary to much for a "fresh" rebuilt.

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

I had to much trust for this guy, I had dealt with him in the past and thought I could trust him. he does know how to properly rebuild a motor as I know he has done hundreds of them..looks like he screwed me good. he now will not answer my calls. I could drive over to his house but, that would likely result in me taking a ride in the back of a police car, and costing me more money than the motor....so I will just have to swallow this one.

HAPPY ST PATTYS DAY TO ALL...

 

[metriccrescentwrench]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

Dang Sparkie, I wonder if you got screwed by the same guy I bought my engine from. He talks really good talk about being an outboard mechanic, told me all kinds of wonderful stories about the engine I bought, and come to find out it was a total POS. I put well over $1000 into it to get it operational after I thought I had bought an engine that was ready to bolt on and go. I'd post his name all over iboats if I thought I could.

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

from the Savannah GA area metric?? more specifically Wilmington Island, has a little shop in his back yard???

Ok heads are off, it appears my cylinders got a good honing, the number 4 cylinder head had some scars, but all the walls seem ok, no slop in the pistons. looks like cyl # 5 is the lucky one that got a new piston. he had some clear silicone around the head orings, I used the black sealant when I did my other motor. not sure if that could make a difference. my other motor was a GL, had high compression, I was told that it had the 175 heads which would cause higher compression and added about %10 HP.

So would you recommend me getting a set of 175 or GL heads??? or maybe shave these heads .30 or .60. I do not think the scarring on the head would be an issue would it?? well here are some pics..any suggestions welcome. Thanks

 

[metriccrescentwrench]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

from the Savannah GA area metric?? more specifically Wilmington Island, has a little shop in his back yard???

Yup, that would be him.

Once I dug into getting my engine running right it became obvious that someone had cobbled something together just enough to get it to run and sell it.

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

good ole Frank..

 

[Haffiman]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

Is the cyl head with damaged combustion chamber from no 3??

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

nope it was on number 4.

 

[Faztbullet]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

Thats just a "cobbled " together motor and the hone job aint worth a crap,the pistons are used(wont build that much carbon in a hour) and #5 is washed so check float level and jet in that one, the exhaust sides are scuffed which is sometimes a sign of worn piston skirts, the head will be ok as dents will fill in with carbon just make sure no metal is embedded in it, and if you want more compression just plug the idle relief port as that will add 10psi instantly (racer trick). I would check this over good before running again as the rod bolts may not be torqued correctly since piston have been messed with....my $.02 is tear it down and do it right as this one has not....:facepalm:

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

where is the idle relief port? and how should I plug it?? the number 5 looked like it was a new piston. the round circle in the middle is larger than the rest of the pistons, could it be that it is new and not washed??
I have never torn a outboard motor down, but I am willing to give it a go, I am a fast learner. thanks

 

[boobie]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

When you get it tore down be sure to put some micrometers to it to make sure what you got. You guys know any good Hit Men ?? LOL.

 

[SparkieBoat]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

what comes around goes around..he has chosen his life..it is a miserable one..I have more peace and joy in one hour than he has probably had in the last year. I will survive with a smile on my face. thanks for all the help.

 

[boobie]

Re: 92 Johnson 150 ois 60 degree..compresion expectation after rebuild??

Good for you Sparkie. We have those same kind of "Hucksters " down here in SW FL.