Wont power up on trailer

Older 70HP Johnson 3 cylinder. Cranks and idles great, runs down the river very nicely and top end speed is good 40mph. Back the trailer into the water and the slightest resistance on the trailer it bogs down and shuts off. It has always done this. I mean it has no power and stalls out easily when you try to drive the bow up on even a little grass creek bank, the trailer or anything like that. It drives me crazy, as this motor seems to run good and have plenty of power in the water. What do you think?

Rick

I feel your pain Rick. Got a 84 70 hp Rude with the same problem. Today it started to stall when put in reverse or forward. Had to just give it the gas. Several times crusing at a fast idle I would have to pump the throttle to get it going. Sure hope somebody can help us out.

I may of just found the problem but wont know until I stick it in the water tomorrow. I just noticed that when you give it throttle, there is additional linkage that moves the plate under the flywheel (timing advance I am sure), well a zip tie from another wire was catching that plate and it was missing its WOT “stop” by a full inch or better. I am saying the timing advance plate was not going its full distance. I redid it and now when I push the throttle down that timing advance plate travels a full 1 or 2 inches further, Do you think that could be it? Where are you Chris V?

Rick

I also heard it sneeze twice before shutting down. I know that usually means a carb is too lean, but there is no air/fuel adjustment scre on these carbs, just a high speed and a low speed jet i believe. How would I make it a little less lean?

Rick

ECU,

I had similar issues with my 130 Johnson and it turned out that the idle orifice passages needed to be cleaned out on the carbs. If you haven’t had the carbs rebuilt in a long time, that’s most likely your problem. Easy to rebuild the carbs with the kits if you’ve got a service manual and a little time.

if its not getting WOT timing advance, it would have a hard time making low end power. my guess is, when you plane off, its slow to get there.
sneezing does usually indicate running lean

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The timing base was definitely missing the WOT rubber stop by 2 inches. It is slow to plane and I was blaming it on the prop. Can’t wait to test it tomorrow. I think i fixed it but we will see.

Rick

This one will plane but is starting to take a double stab from a running start or from neutral to wide open and it is hold on here we go. Just going fro neutral to reverse and give a little gas or to forward with a little gas it is stalling out. Is there such a thing as too long of cables? These are longer than what the manual says the measurement ought to be.

FIXED
Never had so much power and jumps up and runs like a scalded dog.
My timing base was not traveling full distance. Pretty cool as I learned something else and it is always rewarding to trouble shoot and fix your own. Not too likely with the newer computerized motors but these older ones are still pretty simple.

Rick

quote:
Originally posted by ECU1984

FIXED
Never had so much power and jumps up and runs like a scalded dog.
My timing base was not traveling full distance. Pretty cool as I learned something else and it is always rewarding to trouble shoot and fix your own. Not too likely with the newer computerized motors but these older ones are still pretty simple.

Rick


Congrats, now you can celebrate with a new cast net, spinning combo and a few tanks of gas!