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1978 35 Horse Johnson

Sfeder

New member
This boat motor idles and runs excellent at low speed, when you increase throttle it is acting like it is missing or completely shutting off for a split second causing a vibration/shaking the whole boat. It does this from about 1/3 throttle to wide open throttle. I changed the prop and it is still doing the same thing. HELP It almost feels as if the foot hit something in the water, but it is not that there is not a scratch on the new prop!!
 
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Try the low speed needle adjustment, maybe too rich or too lean. Do you know how to adjust it?

I have not adjusted it before and I would have to look in the book to see how it is supposed to be adjusted. Are you positive that the low speed adjustment would cause that violent of a shake? It feels like it hit an obstruction underwater, and I know there are no obstructions like this in the lake I ran it in this morning. The book says to have the engine warmed up to operating temperature then with the motor cover off put it in forward gear and check with a tachometer and it should be 700-750 rpm, if not shut the engine off for safety reasons and readjust until the correct engine speed is obtained.

I appreciate the information and will try it, this sounds like a silly thing to ask. But how would the idle speed out of adjustment cause the problem I have described? I am new to doing anything to outboards and would like to know the reason behind it. If you could elaborate a bit more I would surely appreciate it. Thanks for answering my post.
 
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Check oil in the lower unit.------------Check shift adjustment.----To me it sounds like it is jumping out of gear.---Possibly a clutch dog forward gear problem.
 
this boat motor idles and runs excellent at low speed, when you increase throttle it is acting like it is missing or completely shutting off for a split second causing a vibration/shaking the whole boat. It does this from about 1/3 throttle to wide open throttle. I changed the prop and it is still doing the same thing. Help it almost feels as if the foot hit something in the water, but it is not that there is not a scratch on the new prop!!

sorry i was referring to how it runs at low speeds and spitting when you increase throttle. As for the whole boat shaking take racers advice..............
 
That is sort of what I was afraid of, it being something that will get expensive. I would rather put new parts in than used just for the sake of dependability. Thank you for your reply racerone!!
 
That is sort of what I was afraid of it being something expensive, I will rather put new parts in for the sake of dependability. I thank you for you reply racerone!
 
Check adjustment of cables first.-------See if it will stay in gear if a helper holds the shift handle in forward ( cable disconnected )--------If thiis has been going on for a while it may be too late already.
 
I will give that a try, I have just recently gotten the boat on a loan to a relative and he never was able to pay me back so I went ahead and titled it and put the stickers on it and this is what is going on with it. I have not a lot of money in the boat but I will see if I might find a lower unit somewhere. He never had any problems with it according to him, but I suspect it is too late for the adjustments. We shall see next chance I get to put it in the water. Thanks for your help!!
 
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