1989 GT200 Compression?

[CajunCopper]

Can't find a straight answer. I have a 1989 GT200 model#J200STLCEB. Just has Timer base replaced and compression check done. Mechanic said it was tired and don't expect it to run perfect, which I'm OK with (It is 18 years old). I've searched past posts and google but get different answers and don't find it in my shop manual. My compression is 76, 74, 76, 79, 78 and 80. Have read that the GT's had lower compression and this is find and have read it is too low. I understand being within 5% is good and it is. I know compression gauges vary.

What should compression be? (for it's age)

Any ideas to keep it running smooth for a few more years.

Thanks a bunch,

[TexasHawkeye]

I don't know if this will help but it is for comparision. My 1990 200 HP XP Evinrude, Model # E200STLESE, S/N G02519201 had following compression on 8/2/07: PT = 85 , PM = 82, PB = 80, ST = 80, SM = 83, SB = 85. It is not as strong as it use to be getting out of the hole -- but it still runs OK.

[CajunCopper]

Thanks, I'm hoping the old girl has some years in her. Anybody else got some information?

[Bassmeister]

Those #'s aren't bad for that old girls age, she's just tired. Still got some good running in her, but you might want to consider a refresh soon or an upgrade. JMHO

[DoferGofer]

Have you ever de-carbed this engine, if not I would try that and see if the compression comes up any.



Regards,

[ChampioNman]

It is a low compression motor. Your numbers are fine for the age. You have to decide if you want to spend the $$ to refresh your old gal. On the cheap side, your looking at about $1,600.00-$2K depending on once the head is off an torn down. Block work, and hopefully pistons arent ovaled.
Do a gradual seafoam or ring free treatment via the tank. If you haven't done a engine tuner treatment in many years then the shock of breaking away carbon deposits could lead to more problems then you want.
Although we are big advocates of normal maintenance if the motor has been neglected (not by you) a sudden shock to the iternals can cause issues, so I recommend a gradual approach like eating Oatmeal everyday for 30 days .

[sc419795]

Championman - interesting point on the gradual use of seafoam. Wondering if that is why I blew my head. Compression was checked in July on #3 at 130. Engine still running rough. Added a can of seafoam to a full tank of gas. Still running rough. Same problem as before. Took it to a new mechanic and he showed me where I blew a piston on #3 and compression dropped to 90.

Do you think that the sudden surge of seafoam could have caused a chunk of carbon to move through the system and damage the piston ring?

I know at this point is all speculation - still trying to figure out if I was sold a lemon in July.

In any event - after much thinking I did decide to rebuild the head and replace the VRO. Figured while I am putting $ into a 15 year old engine, keeping my fingers crossed the lower unit and other items not being replaced will hold it together for a couple of years until I upgrade the whole rig.

[CajunCopper]

I've been running Seafoam in it since I've had her, (four years). I have decarbed it once with SeaCreep Spray and it has been winterized every year, (Iowa, we have to do that). In spring I'll decarb and keep running my seafoam, SOUND GOOD?


Thanks for all the great info. Keep it coming if more.

[DoferGofer]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CajunCopper &raquo;</TD></TR><TR><TD CLASS="quote">I've been running Seafoam in it since I've had her, (four years). I have decarbed it once with SeaCreep Spray and it has been winterized every year, (Iowa, we have to do that). In spring I'll decarb and keep running my seafoam, SOUND GOOD?


Thanks for all the great info. Keep it coming if more.
</TD></TR></TABLE>
Sounds good to me. Have you ever tried another compression gauge, just for ha ha ha's? As the pro's have stated, your engine is a little low but not all that bad considering it's age.
I am going to run mine until she don't want to tote the mail anymore then, I am going to hand carry the power head down to South Carolina and personally deliver it to the ChampioNman for a complete overhaul.



Regards,

[ChampioNman]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sc419795 &raquo;</TD></TR><TR><TD CLASS="quote">Do you think that the sudden surge of seafoam could have caused a chunk of carbon to move through the system and damage the piston ring?</TD></TR></TABLE>

Seafoam is good stuff but not that good compared to BRP engine tuner. With BRP tuner you can only let it sit in the motor overnight and not to exceed 16 hours, if you do then metal migration can occur.