No go in drive.

[john8504]

The engine at hand is my 74′ ted Williams 15hp motor. I have battled some demons with this one and had major problems getting it to run this morning. I could get it to idle poorly and then in gear it would not rev very well and just die.

I let it sit for a while because I’m frustrated, 4 hours to be exact. I come back out and start it up on first pull. Idles great! Reverse is great! Forward, no go. Forward has no power and does several seconds after being engaged. Seconds after this video, it died.

What could be going on?

https://youtu.be/Wgg2hHnRkcM

[fisherman6]

It’s tough to tell from the video, but is it running on both cylinders? Also, have you cleaned the carburetor? Just the first things that come to mind. The ignition systems in these motors are kind of delicate and there are not really any available replacements if it fails.
-Ben

OldJohnnyRude on YouTube

[john8504]

Yes carb is clean. Cleaned it several times. It does seem to fire on both cylinders. Good spark on both and 92 compression on both.

[david-bartlett]

Have you had the lower unit apart? Possibly something binding when in forward gear??

[john8504]

Yeah I just did a full service and replaced a bunch of lower unit seals.

This is kinda new symptoms. Before, I couldn’t get it to even run in reverse or forward. Even at idle it was iffy. After the lower unit service, it seemed to get better.

I did put impeller seals in it and I believe I had the impeller on backwards because I had to water coming out of engine. I cleaned out a big nest in lower unit water inlet and in the "pee hole" coming out of the block. Flipping the impeller over, I’m now getting water coming out but I feel that it’s not enough water flow. Might just replace impeller.

[john8504]

David,
The lower gears are all one slide out unit that stay together. The only think that could bind would be the stainless cotter pin that holds the shift rod in place, but I did remedy that problem.

[fisherman6]

How did you measure spark? open air tester set to 1/4"? Spark plugs held against the block and pulled the rope? Are the plugs new? I have had spark plugs fire in open air but not in the cylinder in a compressed fuel-air mixture on more than one occasion.
-Ben

OldJohnnyRude on YouTube

[PugetSoundBoater]

quote Fisherman6:

How did you measure spark? open air tester set to 1/4″? Spark plugs held against the block and pulled the rope? Are the plugs new? I have had spark plugs fire in open air but not in the cylinder in a compressed fuel-air mixture on more than one occasion.
-Ben

On a side note- seems real strange that a spark plug would not fire under compression. Might it be a semi faulty plug? I don’t mean to jack this thread.

"Some people want to know how a watch works, others just want to know what time it is"
Robbie Robertson

[fisherman6]

quote PugetSoundBoater:

quote Fisherman6:

How did you measure spark? open air tester set to 1/4″? Spark plugs held against the block and pulled the rope? Are the plugs new? I have had spark plugs fire in open air but not in the cylinder in a compressed fuel-air mixture on more than one occasion.
-Ben

On a side note- seems real strange that a spark plug would not fire under compression. Might it be a semi faulty plug? I don’t mean to jack this thread.

Either a faulty plug or a fouled plug. Either way I have seen them make a spark in open air, but not make a spark in the cylinder when cranking / running. The resistance is a lot higher across the plug gap in the compressed fuel-air mix. This is why you can see a spark in open air but it sometimes still will not fire in the engine. I use the inline neon spark testers to check them and track down ignition issues to a certain cylinder most often. I have also used a timing light to test them. If the plug doesn’t fire, the inductive pickup won’t fire the Xenon flash. Sometimes the neon testers will still get a dimmer light, but will be considerably brighter on the plug(s) that fire if you use multiple testers at once. I find them handy to track these issues down.
-Ben

OldJohnnyRude on YouTube

[cajuncook1]

quote John8504:

The engine at hand is my 74′ ted Williams 15hp motor. I have battled some demons with this one and had major problems getting it to run this morning. I could get it to idle poorly and then in gear it would not rev very well and just die.

I let it sit for a while because I’m frustrated, 4 hours to be exact. I come back out and start it up on first pull. Idles great! Reverse is great! Forward, no go. Forward has no power and does several seconds after being engaged. Seconds after this video, it died.

What could be going on?

https://youtu.be/Wgg2hHnRkcM

John, I have not worked with your Make and Model motor. It seems it is Eska with Tecumseh 2 stroke powerhead. I was looking for some manuals that might help you out. Maybe you already have manuals but I figured it could not hurt to post them for you. Some have diagnostic and resolution charts.

Even if you have spark on both cylinders, try the drop cylinder test. While the motor is running, disconnect the top spark plug wire from the spark plug. If it dies, then you have spark issues to the bottom cylinder. If it continues running then replace the top spark plug wire back on the top spark plug. Let it run for about 20 seconds then disconnect the bottom spark plug wire from the spark plug. If it dies, then you have spark issues to the top cylinder. This demonstrates that even if you have spark, there may be fault with the coil, condenser or points with the associated cylinder if it can not cause combustion under compression. Please use insulted pliers or heavy insulted gloves to remove the spark plugs wires while running…..zzap gets your attention….lol

As always, check to make sure the fuel cap air tap is opened and not clogged. This will cause fuel delivery issues and poor running.

Cheers,

Cajun

Hope they help you out.

ah817-av520-av600-av750-av817-5-1-meg.pdf

eska 3.0 -.7.5 hp mechanics manual.pdf

eska 3-7.5 old repair manual.pdf

TC, TCH 200 & 300 models..pdf

Tecumseh_2-Cycle_Engines_Service_Information.pdf

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