boat motors...

[imma honky]

Anyone know anything about em? A website I can find some tech? I got a friend who aquired a 50's Yellow Jacket (real nice condition) but we can't get the motor to do it's job. We had it idling today, but when we dropped it in the water, it took off, then died. Now we can't get anything out of it. It's an old 50HP Evinrude (?) or something. Old motor, plus it sat for two years. It has all new fluids and new plugs. Two stroke.

 

[CaptTrev]

hey

ive done some tinkerin with outboards (i have a few myself, and have worked on friends' motors....but mostly newer stuff--70's-present)

but if you can give me a much more in depth description of whats going on and what u have done so far, i may be of more help.


you say u had it idling.....what did u do to get it running?
i assume u had it running in a bucket of water, or with the hose attached to the "ear muffs"?

i dont know that motor specifically, but im sure back then you mixed the oil and gas together. did u mix it the correct ratio?--too much oil would foul out the plugs quick.
not enough (not in such a short time) wouldnt lubricate the piston enough and cause it to cease up.

if it ran out of the water ok, but then didnt run well in the water it coul dbe a bad/plugged up exhaust

carb. might have sucked up some crap when u had it running on land, and then by then time u got it in the water it plugged itself up. (the new, fresh gas might have cleaned out some old crap that was stuck in there)

check carb, drain carb, check plugs for oil/fuel smell/deposits

give me much more info and ill see if i can help

CaptTrev

 

[imma honky]

Yeah we ran it with muffs on. When he first got it, it wouldn't hold idle at all (turned out a plug was bad) so two new ones in, it idled like a champ. We did get a new can of gas in, but im not sure of the mixture (I didn't personally do it, or see the ratio). It ran on the water for maybe a minute or less, then cut off. Then it would crank, cut off, crank, cut off. Had to be paddled back to the trailer. I'm not at his house, so I can't say too much more off hand right now. But he told me after I left, he tried to crank it and nothing happened (im guessing it tries but wont turn). The boat itself is from the 50's (I think a 53) but it originally had an inboard. His dad scrapped the inboard for the out. It was running fine up until two years ago, since then it sat until now. I think the motor is a 70's year, since that would have been about the right year his dad bought it (he passed away in OCT, so...). That's all I can recall off hand right now.

 

[CaptTrev]

well.....

now i'm leaning toward either too much oil in the mix=fouling out plugs

check the plug wires--make sure they all have good contacts
check spark on both of them--look for a good hot spark
if the wires are original--they could be going bad

and again--check the carb., sump, and clean if necessary

this is one of things i wish i could be there to see/hear/smell etc....to see if i could tell more by whats going on.....

keep me posted

CaptTrev

 

[imma honky]

well.....


if the wires are original--they could be going bad



CaptTrev

Is there a way to replace these since they are perminent? THey are original.

 

[CaptTrev]

before you think about replacing the wires...check for a good strong spark

check all wire contacts

 

[01XJLIMITED]

On an old outboard I had, there was a hose that ran from the block to the outer case. This hose was about 4 inches long, about 1.25 id, and was connected with washing machine hose clamps. The function of the hose was to carry the cooling water from the head to the outlet. The engine would idle fine, but when I pushed it, it would stall. The problem was that this hose had a crack in it that caused the carbuerators to choke on the combination of gasses and steam. Replaced the hose, and the problem disappeared. It sounds like a simple job, but it took a long time. There was almost no space to get my hands in there, and there was only about 1 inch of space between the two fixed connecting points. Getting a 4 inch piece of reinforced 1.25 marine exhaust hose into that space took the better part of a couple hours.

 

[Matthew Currie]

Another thing to look at is the fuel pump if it isn't a pressurized tank setup (shouldn't be if the motor is from the 70's). The fuel pumps usually run off of crankcase pressure pulsation, and their diaphragms can go bad. When this happens it will often start and idle but not pump enough to run past idle.

In addition to 01xjlimited's observations, it may not stay running long if the water pump goes bad. When it starts running check if there's water coming back out with the exhaust.

 

[tugalo]

My early Chrysler had a thermal shut-off. It would idle fine, but would cut off when the head overheated. Turned out that dirt-dauber wasps had built a mud nest in the cooling passages, and blocked the flow of cooling water.
Happens when motors are stored in sheds or barns for a while........

 

[imma honky]

Thats for all the input guys, but he scrapped the idea of fixing the boat up to put a v8 in his rx7 (can only manage one project at a time!) I will save all this info for him when he does finally decide to fix it up.
Thanks!