I have an 89 GT175, and according to the boats former owner, has been built, stock I am sure. No VRO.
What can I do to perk it up? Any idea what I should be turning it, its on an 18 foot basshawk boat.
I have not been able to find much on the specs of the motor. Seems to me it should push my boat into the low 70's. Am I missing something?
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96 Javelin 379SE 96 Johnson 150 (J150ELEDB)
Mods: FS carbs, Ficht reed cages, boyesen reeds and
Baker Hot Heads.
Welcome to the BBC.
We will be glad to help with any problems you have but, we don't do any Hop Up here...Sorry.
OK, how about some help with general specifications.
Is this a looper or crosscharged engine?
What are the recommended WOT rpm's. In other words, what is the range? I would be inclined to turn it to about 6k, or so.
Does it have a rev limiter, that will kinda tell me how high I can turn it?
Any problem area's or trouble spots I should pay particular attention to?
Any spark plugs this kind of engine seems to like? Not like?
Thanks
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96 Javelin 379SE 96 Johnson 150 (J150ELEDB)
Mods: FS carbs, Ficht reed cages, boyesen reeds and
Baker Hot Heads.
Welcome Lockjaw,
To answer some of your questions, it is a crossflow.
WOT RPM's 5750.
Yes it has a rev limiter in the power pack.
Displacement is 160.3 cu. in.
Bore 3.625"
Stroke 2.588"
Keep it decarbed and run Ql77jc4 Champions in it.
Mix it at a 50:1 ratio
CM
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96 Javelin 379SE 96 Johnson 150 (J150ELEDB)
Mods: FS carbs, Ficht reed cages, boyesen reeds and
Baker Hot Heads.
If you are still interested in "souping it up" a set of high compression heads, advance the timing, and have it ported will you give you the biggest bang for your buck.
Burning the candle at both ends.
I have to ask, is the no hop up thing in the rules, or just an OMC thing?
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96 Javelin 379SE 96 Johnson 150 (J150ELEDB)
Mods: FS carbs, Ficht reed cages, boyesen reeds and
Baker Hot Heads.
Its a JohnRude board thing, if you would like to Hop Up your motor you will kill the reliability and we are not about that here, we try to help with problems on stock motors.
I apoligize for the post Rusty, thought it was just an OMC thing.
Burning the candle at both ends.
Well I don't want to kill reliability, its more like bolt on stuff like I did with my Tundra. YOu know, cat back exhaust, K&N FIPK, synthetic lubes, and those Bosch plus 4 platinums.
You know what I mean, those little things. I don't want to be stranded on the lake, but I woud also enjoy spanking someone with a larger engine, and having them scratch their head, and go, whats up with that?
You should see the look on those little ricer boys when I get ahold of their honda's with my ZX. Now that is a Mastercard moment.
HAHA
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96 Javelin 379SE 96 Johnson 150 (J150ELEDB)
Mods: FS carbs, Ficht reed cages, boyesen reeds and
Baker Hot Heads.
What do you mean we don't hop up around here? Dang, I'm on the wrong board
First, anything you do to hop up a motor DOES SHORTEN IT'S LIFE. That said there are a few things that can be done to your 175 without hurting it too bad.
You need to find a set of heads from an 83-85 2.6XP or 2.6GT. These will give you a marked improvement over the low compression heads you have now. YOU WILL NEED TO RUN 93 OCTANE AND SOME BOOSTER. The factory says 89 octane for these heads but that was for fuel with lead in it. 93 only!
You will have to re-jet your carbs also.
Remove your airbox, small gain but easy to do. Again re-jet your carbs.
Niether of these mods will increase your rpm range so you can stick with the limited powerpacks.
The flywheel on your motor is what is going to limit you from doing any mods that raise the rpm, it is just to heavy and it will break off at the crankshaft if you spin it much past 6400 rpm.
Your 175 is basically a detuned 235, It has the same heads but the porting is lower on the 175 (good torque!!!) Same carbs too. The flywheel also robs about 7hp. You could change the flywheel but you would need to change a bunch of electronics also and if you aren't going to port it then it isn't worth it.
Add Boysen reeds to the intake. They make a difference on these old motors. You can also add a set of intake stuffers from a 235 or 2.6GT/XP while you have the intake off. I don't think the 175's had them.
These mods should give you about 200+ hp at the prop.
One last thought, stay away from racing lower unit lubes unless you are going to race. They are too thin for everyday use. Also use synthetic oil only. The new Evinrude XD100 is a great oil and will reduce carbon which these old crossflows like to collect.
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