Anyone know anything about marine mechanics?

[Cody Gruchow]

I have a few questions for anyone who knows about outboards

[HD]

I've repaired my share of boat motors, but Dew should be able to help you.

What questions do you have?

[dew2]

I have a few questions for anyone who knows about outboards

What are your questions Cody.

[Cody Gruchow]

I have a 1984 Yamaha eln 40 horse tiller. I bought the engine as a project to help learn how to rebuild them. I rebuilt the entire powerhead one new piston all new piston rings, honed the cylinders. There was no scorching in the cylinders luckily. So I got it all done and put oil in cylinders and turned the flywheel to lube up the cylinder walls. Then I checked spark and that's strong. Engine fired right up. I haven't done a compression test yet. But I'm having some issues that I've run into a dead end on.

1. Exhaust was spitting white smoke and its oil injection so I know that's not right, put my hand behind it and smelled it off my fingers and it smelled like pure gasoline. So that means the oil pump isn't working correct? I mixed some gas 50-1 mixture of Yamalube an seemed to slightly fix the problem.
2. Cooling line works every other time. Spits water at a good stream and its hot, then I turn off motor and run again very shortly and then it doesn't spit anything at all. New impeller needed?
3. And the biggest issue. I put the engine into gear and run it(when the impeller is spitting water of course) I turn the throttle 1/4 ways and it accelerates then I turn it more and it won't accelerate anymore or even try to, engine doesn't spit or act likes its dying at all, it just won't give anymore power. This is my biggest problem I would like to figure out but I can't find nothing about it in the manual.
Thanks

[dew2]

Troubleshoot one thing at a time.
 Power loss is first.Put a timing light on each plug wire,while its running,Look at the light and see if all cylinders are fireing. Gas out the exhaust leads me to believe they arent. Then mark all 3 flywheel timing marks one white one black and one plain to differentiate each and see how close timing is, It is a 3 cyl right? That or any 2-3-4 cylinder can start and run on one cylinder.
 If no spark on any hole look to the CDI,Rectifier or stator for shorts or poor contact. Google CDI UMMM I'll just put the site up so you can OHM out CDI,Rectifier and stator to see if any are shot.
 You should have replaced the impeller when rebuilding it is easy,
 White smoke?? Seafoam burns white smoke and some other additives.DONT USE ANY till the rings are seated and the over oiling is good for the first few hours on a newly reringed engine.
 Check that and next the oiler keep the mixed fuel in the tank till all is resolved.

 Yamaha is page 97-101>>>>http://issuu.com/cdielectronics/docs/troubleshootingguide?mode=embed&layout=http%3A%2F%2Fskin.issuu.com%2Fv%2Fcolor%2Flayout.xml&backgroundColor=000000&showFlipBtn=true


 What was originally the problem with the motor before you bought it?

[Cody Gruchow]

Well I did buy a whole new water pump kit for it but they sent me the wrong one an are being a pain in the rear about returning it. It will be the last time I deal with them. The cdi was replaced by the guy I bought it from a couple months before I bought it. I did add a small amount of sea foam to the gas. Maybe two cap fulls worth. I pull the plug wires one at a time as its running and the top 2 you can hear a difference but when I pull #3 there's no difference in the running. Pulled all plugs to look at them and 1 and 2 are dark and smell right an #3 doesn't seem nearly as dirty/dark as the other two. I checked rings before even initially starting it up to make sure they seated right and they were And had a spring to it when pushing them down with a small flathead and releasing them. That's what the book said to do.

[dew2]

 Take a ignition coil off #1 or #2 and  stick it on 3 with #3 on the one that you took off 1 or 2.See if 3 fires.If it does and the other cylinder isnt fireing you have a bad coil.
 Got to get all 3 fireing then move on. Timing light is so helpful!
 Myself I never replace whole water pump unless I see its defective,Just a impeller.
 Right now compression should be checked also,It will change once rings are seated,IT also will read high with lots of oil in the cylinders>>BUT see if they are all within 10% or less of eachother 10% MAX for now.Like I said after running a few hours it will change abd be more accurate

[dew2]

 Cody who are you buying parts from? The water pump especially. They do send out what you order??How was that mistake made? The main question is who did you buy from?