blown powerhead?

jamesbalog · #1 08-06-2014, 01:18 PM

1990 johnson 175 is the motor, with vro.

Running back in last night she shut down on us. I wasnt driving, sounded like we were at about 3/4 throttle. No vro alarms went off, just shut down out of no where.

Motor would not restart in neutral. If you took it out of gear and gave it 1/4 to half throttle it would fire up but as soon as you would back off the throttle she would stall.

I havent gotten down to run a compression test yet but im guessing we blew some pistons. Does this sound like a good guess?

Besides a compression test is there anything else we should look at?

If it is the pistons there will most likely be a 20 fisherman with a parts motor and trailer for sale dirt cheap in ohio***128557;

bigshrimpin · #2 08-06-2014, 03:00 PM

Do a compression test first . . . and DO NOT start or run the motor until you do.

could be something as simple as a bad fuel pump.

jamesbalog · #3 08-09-2014, 06:50 PM

Compression results

5 cylinders at 90
1 at 60

Time for a new one

phatdaddy · #4 08-09-2014, 08:11 PM

i would at least pull the heads off and look before i pulled the plug on that motor.

jamesbalog · #5 08-09-2014, 08:46 PM

Theres an outboard guy around here that ive heard is very good and very reasonable on price.

Ill be giving him a call monday, atleast see what he has to say

RidgeRunner · #6 08-10-2014, 09:11 AM

Probably went lean and burned a piston. Crap gas and hot weather pre-detonation city.

spoggy · #7 08-12-2014, 12:01 AM

Quote:

Originally Posted by jamesbalog

Theres an outboard guy around here that ive heard is very good and very reasonable on price.

Ill be giving him a call monday, atleast see what he has to say

Sorry for that 60psi cylinder, doesn't sound good. I think you're in my neighborhood, I'm in Carlisle Twp. Who's the outboard guy?

THEFERMANATOR · #8 08-13-2014, 02:34 PM

Quote:

Originally Posted by jamesbalog

Compression results

5 cylinders at 90
1 at 60

Time for a new one

I've seen engines ALOT worse than that run for years. It isn't ideal, but unless that low cylinder has a stuck ring it should still run(just be slightly down on power from the weak cylinder).

jamesbalog · #9 08-14-2014, 03:37 PM

Quote:

Originally Posted by THEFERMANATOR

I've seen engines ALOT worse than that run for years. It isn't ideal, but unless that low cylinder has a stuck ring it should still run(just be slightly down on power from the weak cylinder).

I fired it up, it ran didnt want to start in neutral but would start with a little throttle and would idle back down... it sounded like there was a little bit of rattling going on and i shut her down right away.

anyone have any insight on that?

THEFERMANATOR · #10 08-14-2014, 04:52 PM

Quote:

Originally Posted by jamesbalog

I fired it up, it ran didnt want to start in neutral but would start with a little throttle and would idle back down... it sounded like there was a little bit of rattling going on and i shut her down right away.

anyone have any insight on that?

Rattling is a bad sound to hear in a 2 stroke engine. If it's piston slap, it's to be expected in an engine with slightly lower compression on one cylinder, but it could be worse.