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outboard stuck in slow gear

A

Azza

New member
hey guys, im just wondering what ive done to my motor. its a 2 stroke 40hp mariner 676b 1981. as the motor is old it has troube going slow enough to troll. so we put 2 buckets on ropes to slow the pace down. long story short the motor didnt like it in the long run and now when in gear it wont go full speed, wont even go half.

neutral revs normal, it can go in reverse but i think it doesnt reverse as fast as it used to.

to me it looks like i buggered the gearbox but i dont know much about outboards yet and hopeing there may be a simpler/ smaller problem.

so to be clear i can rev it hard in neutral but in gear it only revs about a quater thus the boat speed is minimal.

thanks for any help in advance.
 
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Revving in nuetral means nothing.-------Towing the buckets did no harm.-----Do a compression check on it .-----------Then check and see if you have spark at each plug that will jump a gap of 3/8" with a snap you can hear.
 
Sparkplugs will -" foul "------in a cylinder that is not producing any heat , this can be due to poor compression.Also fuel problems such as a broken / chipped reed valve, or flooding carburetors etc etc.
 
i was aware that u can fowl the plugs but i didnt know u could do it beyond repair. i put the old ones in and it should be ok now, one plug had no spark and the other only a weak one. thanks for the input guys it was very helpful, time for an electric trolling motor i think.

on a completely different topic, when i bought the motor the 'oil seal housing' at the bottom of the engine on the crank was corroded. it was impossible to find a replacement so i ended up buying a dressed engine block from a 1997 (i think) yamaha. they have the same design and it would fit but the mechanics couldnt be bothered re wiring one of the parts (harness i think). the boat was giving them headaches and i also wanted it back asap.

so i ended up with the same old block but with a few new parts on it like the starter motor from the yam. my question is would it be worth my while payin them a couple of hours to intall the newer yamaha engine or would i not notice much difference? its pretty much the same engine but probably has more compression (they said my current one has a reasonable ammount), and dual carbys. would the power difference be noticeable or should i just keep it for when this old one has had enough?
 
Who knows? I swaped my '78 powerhead for a '86 that had "good compression". It turns out, it had a bearing going out and it threw a rod shortly after the swap.
As long as you still have compression' you're good. I would save it until you need it.
 
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