Question for the OMC God!!

macojoe · #1 10-10-2006, 09:02 PM

You know that 1988 175hp Evinrude my budy had I was working on, well he wants to repower and has offered me the motor.

The motor runs great now that I have got all the bugs out of it for him!!

He is running it on a 20' Grady walk around.

Now here is the thing, one of the problems we had was that when you got it on the water it would run then start to surg, no gas then have gas and so on, it would start real hard if we shut it down??

This would go on for a bit then she smooth out and be fine the rest of the day!! I mean start like a light switch, and sound great while it moved us 35 mph+

Then one day out with another friend it started again, he had noticed that there was a clamp missing on the fuel line, we replaced and ran great the whole day.

Now when you start her up and take off you get a small and I mean small surge were it wants to take off, this will just be a few times with in let say 1/2 mile then never agaim the whole day.

ReAlly sounds great, and pushes great, just this worries me a bit??

Have you heard of anything like this before?? I can get the motor for $700 maybe a bit less??

what you think?? I will try to get some pic tomorrow

pikfish · #2 10-10-2006, 11:20 PM

It could be many things, The first question that comes to mind would be; Is the fuel bulb equally as firm while it is misbehaving as it normally is? This might answer some questions about fuel delivery.
From there I would ask about the temp. when the problems start? If that had any relationship to the problem?

macojoe · #3 10-10-2006, 11:35 PM

Well the ball stays almost hard, can squeez a little.

Temp is not the problem!! this is when you first start of the day, use to be anytime till we got the clamps on??

Pumps water and the heads are nothing but warm after a 7 mile run.

Thanks!

Skools Out · #4 10-11-2006, 01:24 AM

i know exactly what you've got had the same problem and pulled out lots of hair till i found out i had a bad electronics pack. Motor would run great some days run crappy and loaf the next. hard to start some days and crank on a turn the next. Now as to which one is bad can't help ya there i say buy one pack then try on one bank see if problems goes away if not put the old set on the other side and try again.

macojoe · #5 10-11-2006, 01:57 AM

that is the power pack you are talking about??

I have seen them on ebay for like $50

but the motor sounds real good!! CB has heard it and says the same.

Think its worth $700??

What should the compresion be like in that motor??

Thanks!

Skools Out · #6 10-11-2006, 02:08 AM

factory was around 120 psi and $700 is agreat buy. But just because it sounds good doesn't mean it is running at the best it can. yeah power pack will be the issue. that is a need to fix issue due to it will end up burning a piston or cylinder.

macojoe · #7 10-11-2006, 02:33 AM

If I buy a power pack and thats not it, could it be a bad coil or something like that??

Skools Out · #8 10-11-2006, 02:42 AM

um never seen a coil do that but it's poss.

chumbucket · #9 10-11-2006, 04:09 AM

I dunno. From what I heard, it sounded more like the motor was cutting out momentarily rather than surging. I still think it's a fuel related problem. But, I've been wrong once or twice in the past. Skools is definately more "skooled" than me in this area. That's for sure.
Skools; from what I heard, it seems to cut out momentarily only for a short time after iniatial startup for the day. Once it clears up, it didn't seem to happen again all day. Could a bad diaphragm in the fuel pump cause intermittent problems if it were getting aged a bit. I can imagine that upon startup, the diaphragm may be not so flexible. Then after running a bit more, start working more effectively. Is that even possible? I know I'm probably reaching a bit here. It just didn't seem to be electrical to me.
Like I said; I dunno. ???

It certainly does seem to run like a champ once it clears up though. Sounds good. Plenty of torque. I think it would make a good motor for MJ if he can get it for the $700.

#10 10-11-2006, 07:03 AM

could be lots of things.stator, old fuel hose, reed, ring... does it 'chirp' at idle? have you looked at the magnets? more than likely hte cdbox like like skoolz said. them things are funny. sometime they run fine till they get warm. sometimes its the opposite. sometimes they just screw with ur mind for fun! i wouldnt buy a used one though. or a sierra for that matter. diaphrams are also cheap. but, for 700 bucks its hard to go wrong. good luck.