Compression on 93 Evinrude?

[NTMID8]

Hey guys my engine was compression tested at its serviced (1993 60hp 2strk) with a reading of 145psi on all three cylinders. Stupid question but what is the norm for these engines?

To clarify i have no issues with the engine just would like to know what the factory spec is.

Cheers

[Spaniard_King]

IMO your mechanic needs a new comp gauge:P

I could never get one of those 60's to go over 120psi

[FNQCairns]

Gary the smaller engines where a bit higher than the larger engines from memory, still 140+ is getting up there especially on today's crap fuels. Regardless I wouldn't be worried about that reading in any way as being low, lots of hours left no matter how you cut it.

Possibly he reached for the tester he uses for potential sales, lucky he didn't grab the one he used to asses trade ins:)

[NTMID8]

lol, i guess it was in his interest to suggest that it was broken if he wanted more money.........

I would be very interested to find the OEM specs for the engine as the guy i bought it from suggested it only had around 100 - 150hrs, the mechanic i took it to suggested it looked as if it was closer to the 100hr mark given the even compression, next to no smoke and something about a snake bore inspection???

[Spaniard_King]

Possibly he reached for the tester he uses for potential sales, lucky he didn't grab the one he used to asses trade ins:)

Thats more to the point!!!!!

Huey must have done his fair share of these?? I wonder if he will add his $0.02 worth:o

[finga]

something about a snake bore inspection???
It's just a scope they shove in where the spark plug normally lives to have a bit of a gander at the bores to see if there are any scores or marks.
They look like this.
http://www.aunet.com.au/video_borescope_camera.htm

That price isn't too bad either I have to say :D

The main thing about the compression readings is that they are all the same.
If they varied more then 5 psi then I'd want to know more.

The reading sounds high though.

[Spaniard_King]

Why didnt ya put that borescope link up yesterday.. been lookin for a good one of those for a while now :P

[finga]

Why didnt ya put that borescope link up yesterday.. been lookin for a good one of those for a while now :P
Did you get one??
There are better prices about for the same thinga-me-jig.
http://cgi.ebay.com.au/Car-Inspection-Video-BORESCOPE-Flexible-Snake-Camera-/270583974125?cmd=ViewItem&pt=AU_Hand_Tools&hash=item3f000fc8ed

http://www.dealextreme.com/details.dx/sku.32414

And sorry :-?

What else are you wanting?? I might have one in the shed.

[Spaniard_King]

Not yet but that last link has definately got me interested. The Minister for finance might just pass a request for that one :)

[finga]

There also USB ones about that plug into the laptop if you use one (laptop that is) all the time.
Like this but there's tons of them available
http://cgi.ebay.com.au/USB-FLEXIBLE-SNAKE-CAMERA-SCOPE-BORESCOPE-INSPECTION-/220627126232?cmd=ViewItem&pt=LH_DefaultDomain_15&hash=item335e66c7d8

[Steeler]

Why didnt ya put that borescope link up yesterday.. been lookin for a good one of those for a while now :P

Garry

My Tohi dealer buddy purchased one about a month ago from snap on tools which also had the capability to record so he could down load it onto his PC and then view it again.

I was talking to him last Monday and he said its been great to show customers when they return from having there motor health checked any internal wear and tear from his computer.

Steeler

[Spaniard_King]

Yeh ... definately on my list of kit to buy.. thinking that laptop one would be good.. should be able to record it .. then I could email it to clients :)

[Huey]

Thats more to the point!!!!!

Huey must have done his fair share of these?? I wonder if he will add his $0.02 worth:o

What is problem mate? We use an expenisve Snap-on compression gauge and if I am trading an engine I will also do a leak down test too because as i am sure you are aware a compression test is one test but leak down can show hidden results that a compression test can not. As for your reading yes I agree it is a touch high but as long as they are even than that is the main thing.

You have a problem with me Garry?

Cheers,

Huey.

PS-8 minutes latter. I just walked out to a HH 445C that has an ET (i am sure you will now what that year model that is Garry) model 70HP Johnson on it, that we sold new all those years ago and doing a compression test on this engine - no.1 was 137. No.2 was 134 and no.3 was 130PSI on our Snap-On compression gauge. Now if I was going to trade this engine I would also do again warm and a leak down test and also water test to make sure I can resell with confidence like we have done since 1964.

[Spaniard_King]

No Huey,

Just new would have done a few of these and would make good reference to the actual readings. :)

[Huey]

All good then my end mate and as you see from my "PS" in the above post all gauges will read different and as for the orginal poster if that engine, being a 1993 model, has the original cylinder head gasket i would suggest, as preventative maintainance, to replace the gasket and when doing it you can see the condition of the bores and also any signs of corrosion. To do this would be under $200 and worth it.

Cheers,

Huey.

[FNQCairns]

lol, i guess it was in his interest to suggest that it was broken if he wanted more money.........

I would be very interested to find the OEM specs for the engine as the guy i bought it from suggested it only had around 100 - 150hrs, the mechanic i took it to suggested it looked as if it was closer to the 100hr mark given the even compression, next to no smoke and something about a snake bore inspection???

There is none for compression readings that I have seen, it's done through general knowledge based on history. Anyway OMC never did have this as a solid spec i am sure, even on new engines it can vary but still be fully serviceable, imagine the new owner concerns if a manufacturer did list it's expected compression reading.

I just then googled and found everything from 110 to 130psi, this fits the general historic model of outboard engines, yours where all even and high which meets the most important pass criteria for this type of test...assuming all pots degrade due to normal wear and tear only, it still has 3000+hours of good serviceable life ahead.....it will not get there because the owner will kill a 2 stroke far earlier 99% of the time....I would be thrilled to buy an engine of that age with that reading and if it looks near brand new too! tickled is the word.

[Steeler]

3000 + hrs,only from those beautiful black ones;):P.


Sorry could not help myself,been very quite lately no Fisher threads,no Toyo v Nissan v Disco.No 2 stroke v 4 stroke.

At this rate Mod5 will be able to take a WELL DESERVED holiday;).

Steeler

[FNQCairns]

3000 + hrs,only from those beautiful black ones;):P.


Sorry could not help myself,been very quite lately no Fisher threads,no Toyo v Nissan v Disco.No 2 stroke v 4 stroke.

Steeler


Given the circumstance you noted...no need to apologise;D

[NTMID8]

All good then my end mate and as you see from my "PS" in the above post all gauges will read different and as for the orginal poster if that engine, being a 1993 model, has the original cylinder head gasket i would suggest, as preventative maintainance, to replace the gasket and when doing it you can see the condition of the bores and also any signs of corrosion. To do this would be under $200 and worth it.

Cheers,

Huey.


So your suggesting replacing the gasket just incase? This wouldnt be seen as possibly creating a problem?

Engine looks to be in very good order, like i said though i have no issues with it just thought id see. I used to be a motor mechanic and car manufacturers would list a "norm compression ratio" but could not find the specs on outboards but now i know they dont list them ;D

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[Hornet Rider]

So your suggesting replacing the gasket just incase? This wouldnt be seen as possibly creating a problem?

Engine looks to be in very good order, like i said though i have no issues with it just thought id see. I used to be a motor mechanic and car manufacturers would list a "norm compression ratio" but could not find the specs on outboards but now i know they dont list them ;D

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The expense of replacing the gasket might be a useful investment for peace of mind. I picked up a 98 Johno 70 2st with 370 hours on it about 18 mth ago from an old bloke near coffs who had it from original, with service dockets. Beautifully kept outboard although he didn't ever cover it in the back yard & there was UV damage to the paint & decals. My mech did the service & suggested if I intended to keep it why not replace the head gasket, new head bolts & give the power head a slight shave if needed. Did all that & had a good look inside at the same time - no probs. I try to get out to deep tempest, hutchies, wide caloundra & don't mind pushing the weather a bit. On balance, I shouldn't suffer a head gasket blow out coming home, latter than I should be, in uncomfortable weather in the dark. Replacing your 93 gasket is good advice, but you'd have to decide on when, where & how hard you're going to work your motor.

cheers, HR