Evinrude

[Kriegs]

Good friend just dropped of an evinrude 18hp.... Not sure what it is. Looks just like my qd-19 other then the power head. So he said the motor was working fine going full speed. Got to fishing spot. Fished for awhile. Fired motor up. Put it in F the boat would only go 4mph. Stopped the engine nothing in the prop. Start it up put on R only went about 1mph. Did it a few times nothing changed. Card works good because in N he can run it and super high rmps. But not F or R. Dropped lower unit and gear case. Gears are great shape. And the only thing I can see that's worn is the lowest part of the drive shaft with the part that goes into the gears.... To me it should work. Plugs wires good. Condensers good points/ coils are new. Getting spark. It's like it's not shifting all the way. Plz help. I told he should rebuild the lower unit. Oil mixing with water a good amount of it. That was after he drained it looking for metal. Then put new oil in.
Hope this all makes sense thanks!!

 

[Kriegs]

Model number is 15028 03295.

 

[jimmbo]

I doubt the gear case has anything to do with this engines trouble. There is no such thing as "not shifting all the way". It either is in gear or not. "super high revs" in neutral have been the death blow to many an engine. Before he started gutting the engine, did he check to see if the throttle linkage was complete and the carb was fully opening when the throttle was fully advanced? Gas in tank? Fuel line kinked? How old was the gas? Was a compression test done? What condition were the spark plugs. wet, carboned up, was the gap correct?

 

[Kriegs]

Well the crab must have been working fine. If it was working an hour before. Linkage looked fine to me from hat I saw. Good gas full tank... Made sure. I did the compression test. Spot on 100psi top and bottom. The plus both where wet. Both caboned up don't think that would be an issue. Just because the motor ran good rpms started great idled great. Works great. Just wont go full speed or even half speedGap was good.

 

[Kriegs]

What about the main gear under the power head... Maybe slipping. Or missing teeth?

 

[jimmbo]

Carbs plug up, one minute they are fine, the next, a piece of dirt, a glob of gum/varnish plugs a jet/airbleed/ passage. Did you operate the throttle to see if the spark was advancing and that the carb was indeed opening? An engine that can't run through it's entire speed range, is not working good, let alone great

 

[F_R]

Let's start over. Exactly what happens when you put it in gear and give it the gas. Does it continue to run, but slow RPMs? Or does it run crazy wild (in gear) but not go anywhere. From what you said so far, it sounds as though the first scenario is what is happening. If that is true, find out why it is running on one cylinder. Have you checked the compression? Have you checked the spark? Possibly getting water into one of the cylinders? Or could be as simple as a bad spark plug.

But if the second scenario applies, running crazy wild in gear, but not going anywhere, you have a spun propeller hub.

 

[Kriegs]

When I put it in gear the RPMs stay low and the motor runs fine. It will go in just at the low RPMs maybe 5mph in Forward. The when I accelerate it seems to not grab or something because it just doesn't go anywhere after a certain RPM. I can give it gas and run the RPMS high no problem as well. From what I can tell Motor runs fine no matter how much gas I give it. I have checked spark plugs good. Compression both cylinders good right at 100 psi for both.
He sent be this. In a text. Maybe this will help

 

[Kriegs]

I don't really deal any sort of crazy vibration or know could kicking when I am in gear at all. All that happens is I accelerate and after certain speed or pressure I loose all thrust on on the motor and have no idea why because seems to run good, gears look, prop looks good, compression holds, and RPM's seem to hit there high level they need to.

 

[Kriegs]

Yes, will only hit a certain point then stop. The prop will stop spinning as well unless I lower my RPMs back down as well

 

[racerone]

Why not try another prop ?

 

[Chinewalker]

Sounds like a spun hub on the propeller. Easy to check - use a Sharpie and mark the prop nut and propeller in a line. Then run the motor. If the marks no longer line up, hub is spun.

 

[Kriegs]

Ened up being g a spun prop. But I rebuilt the lower unit too