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Reply With QuoteI think the oil pump is worn down. Not getting enough pressure at low rpm. I mean you HAVE taken everything else apart
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Crappie Wall Hanger II
I've had the water pump apart about a hundred times now it seems. No obstructions in the pump. It pumps good water to the tell-tale. Beyond that who knows but as you can see the passages are clear, the holes to the front and back of the jacket are open.
It has 3 individual carbs. Oil is injected post carb into the reed plate i believe and is "metered" into the cylinder according to rpm by virtue of the gear driven oil pump that increases flow with rpm. I have a low rpm problem only with the alarm.
I am thinking oil system now. Can't be anything else. Water flow is a good a i can make it with all new parts.
Regarding the scoring in top cylinder. You can see it but you can't feel anything. It isn't deep enough to actually feel even if you drag a finger nail across it.
Re motor height, no jack plate only tilt trim. Cav plate is even with our just a hair above bottom of boat. I haven't messed with it since I've owned it. I've owned it about 7 years. Problem first started in around March of 2020. I do tend to have more issues when idling trimmed up though but i typically trim up some when i idle so it may be coincidental.
Crappie Wall Hanger II
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I think the oil pump is worn down. Not getting enough pressure at low rpm. I mean you HAVE taken everything else apart
Crappie Wall Hanger II
Slabmaster
then wouldn't a pretty simple test be to mix a weak solution of 2 cycle gas, and see if it fixes the issue? Say a 50:1 or even 60:1? Give it enough oil in the gas that any other oil mixing in won't foul out the plugsOriginally Posted by Baitwaster
I think the oil pump is worn down. Not getting enough pressure at low rpm. I mean you HAVE taken everything else apart
Crappie Wall Hanger II
I'll pull that whole oil system. I have several portable tanks around here. One has fresh 50:1 mix. I'll purge that oil injection system and give it a good visual exam, replace what might be broke.
Looks like it could only be a ~$165 oil pump or ~$35 drive gear. Much cheaper than a new engine.
Crappie Wall Hanger II
Your service information should have a procedure for checking oil pump output.
For my Suzuki, you essentially use a graduated cylinder with a hose barb on the bottom, and a short hose to the oil pump inlet. You bleed the system, run the engine at a certain RPM for a certain amount of time, and measure how much oil it consumes. It's not really an exact science, and it won't show if the pump is distributing oil evenly, but gives you an idea anyway.
The throttle rod on the oil pump should be adjustable to get the pump output within spec.
Crappie Wall Hanger II
It does. It might be easier for me to just pull the system apart and look for issues though.
Crappie Wall Hanger II
Not oil. Put it all back together and ran it on pre-mix 50:1 in a garbage can. Ran about 5 minutes and the alarm went off. It never registered water pressure on the gauge. The outlet for the water pressure tube is downstream of the thermostat. So either thermostat is not owning (which thermostat is good, I tested it in a small pot on the stove) or in just not making, or losing water pressure.
I'm tapping out and taking it to a mechanic next week. Hopefully all the things i have already done can help speed things up for them.
Crappie Wall Hanger II
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Keep us posted, we're all as curious as you are fed up.
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Jake
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Replaced the impeller yet again since I opened it up to make 100% sure it was in the housing correctly. It was. New one is too.
One thing about this particular housing is the water tube just shoves down into the tapered spot. There is not a real good seal with the grommet design. It doesn't push into the housing the way others do. You can see on the shot of the water tube in the mid leg where the seals and grommet ride up and how far the water tube pushed down into the housing.
