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1990 175 hp evinrude

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kmbvhlowe

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I have a 1990 175 Hp evinrude. I just recently purchased the boat. The previous owner said he hadn't ran it in a couple of years. I have completely drained the tank and replace fuel. I have completely rebuilt the carbs and replaced the spark plugs. This seemed to definitely improve the performance of the engine, but, I still at times have to choke a hot motor or use starter fluid to get the engine to start. It has no problem with firing. In fact usually when it will not start, it will fire once but not start. It has very little power. When not in gear it will crank to 7 or 8k rpms, If in gear and the boat is trimmed out, the best you can get is 3800 and 25 mph. It DRINKS gas. About a gallon per mile travelled. Would the timing be an issue, and if so, how do I check it???
 
Re: 175 hp evinrude

I would first check the compression. By the way, not a good idea to run that engine up to 7 or 8 k with no load. Those crossflows are not easy on gas but a gallon per mile is excessive. What spark plugs are you running?
 
Re: 175 hp evinrude

I am running a new set of NGK's. It had champions on it when I bought it, but was trying hotter plug hoping it would improve performance. On the other note, I purchased a compression test kit today and am planning on testing tomorrow. Where should it be?? Around 100?
 
Re: 175 hp evinrude

Go back to the Champion plugs specified for that engine.

Don't use starter fluid, use pre-mix in a spray bottle. The only source of lube in the engine is the fuel and if you use starter fluid, you're running it (for a short time of course) without any lube.

For your other questions, I'd suggest getting a OEM service manual from ebay or outboardbooks.com and go through the compression, spark and fuel troubleshooting procedures. There's a good section in another boating forum that could also help. http://forums.iboats.com/forumdisplay.php?f=31 Look especially for "Awakening a Sleeping Outboard"

Compression: I've owned two V6's, current a 1990 200 hp. Both had "normal, like new" compression in the 90-100 range, so anything around there or even the high 80's would be expected. The old rule of thumb "above 100" doesn't apply to these engines. You do want them to be even though (generally recommended within 10% high to low). You won't find an actual printed spec for this, but I've never seen an OMC V6 discussed here or anywhere else that wasn't like this.

As for crossflow vs. looper - it probably makes no difference in troubleshooting your issues, but I'm not sure if it's a crossflow as suggested. My 1990 200 hp (also a V6) is a looper, I wonder if they made both crossflow and looper V6's in 1990? Just curious.
 
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Re: 175 hp evinrude

Well, I did compression test today. All cyl right around 100 except for #1 which is only reading 30. Will rings fix and if so, how difficult is it to change them. How much $$$$? roughly.
 
Re: 175 hp evinrude

Sorry to hear that. With pressure that low piston is probably destroyed, and the cylinder wall badly scored. Any type of repair requires the powerhead to be removed, and complete dissasembly. Bad cylinder will need to be either bored or re-sleeved. Most people change all the rings and rod & pin bearings while they are at it. Basic rebuild probably starts in the $2,500 range. "Do-it yourself" rebuild at about half that. If you are mechanically inclined, and know how to remove corroded bolts with a propance torch without wringing them off, you may be able to tackle this yourself. Unfortunately, an engine with a bad piston is probably worth only about $500 as a parts engine anyway, might make a great project.
 
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