need help with OMC 2.3 liter

[prdmetalworks]

Just purchased my first boat, was going to get a nice one right off the bat & my wife talked me into getting a "good" cheap one first to see if we really liked boating before making a big purchase. Long story short, we ended up getting a 1989 Chapperal 190 with an OMC 2.3 liter Cobra TKO4.
The motor runs great on muffs, but when you dump it in the water, it runs like crap! The first time I tried it out, it would take forever to come up on plane, and you couldn't give her any more than 1/2 throttle, or it would fall on its face. I immediatly took it home, replaced points, condensors, cap, rotor, and completly rebuilt the carb. Once again, ran great on muffs, put it in the water, now its even worse! Can't get it up on plane at all, and can't go past 1/4 throttle, or it starts bogging & stumbling. I'm at a loss! I already have more into this boat than I wanted to invest in a older boat, and dont really want to bring it to the marina & drop even more on it, so is there anything I should be looking at before I try to sell it to get something else?

thanks in advance

EDIT: first test run was with just 2 people, 2nd run was just myself

 

[Gary H NC]

Re: need help with OMC 2.3 liter

Old fuel,dirty fuel filter...Compression test?
How long has it been setting before you bought it?

The next boat make sure its not a OMC or a Merc with the 470 engine!

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

Fuel tank was filled & Stabil added during winterization in Nov 08'. Havn't checked compression, but it does start right up & run great on muffs. Installed new fuel filter while doing points just a couple of days ago.

 

[Gary H NC]

Re: need help with OMC 2.3 liter

I would still check compression,timing and maybe try a portable tank of fresh fuel for a test run..
Fuel pickup could be clogged in the tank or the anti-siphon valve sticking.
Both will create a fuel starvation.

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

I'll give a shot & let you know how it goes.

 

[Gary H NC]

Re: need help with OMC 2.3 liter

Good luck!

 

[sea wolf]

Re: need help with OMC 2.3 liter

Fuel tank was filled & Stabil added during winterization in Nov 08'. Havn't checked compression, but it does start right up & run great on muffs. Installed new fuel filter while doing points just a couple of days ago.

Did you replace both fuel filters?

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

"both" fuel filters? Are you talking about the pickup filter in the tank? I am going to try to run out of a temp. tank in the morning w/ some fresh gas & see how it goes. I let you guys know

 

[sea wolf]

Re: need help with OMC 2.3 liter

"both" fuel filters? Are you talking about the pickup filter in the tank? I am going to try to run out of a temp. tank in the morning w/ some fresh gas & see how it goes. I let you guys know

Sorry. I forgot you had the 2.3. So, my question doesn't apply.

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

I've already mentioned that I am brand new to this, so forgive me if this is a dumb question - is there any way to simulate running the engine under load without actually going to the water everytime I want to test? I was thinking maybe a 55 gal. drum of water

 

[Don S]

Re: need help with OMC 2.3 liter

I've already mentioned that I am brand new to this, so forgive me if this is a dumb question - is there any way to simulate running the engine under load without actually going to the water everytime I want to test? I was thinking maybe a 55 gal. drum of water

Sure, get yourself a marine Dyno. http://www.internationaldyno.com/products.html

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

Just got back from another disappointing test run
I ran it out of a temp. gas can with fresh 93 octane, and it ran the same as the last run, couldn't go past 1/4 throttle, or it would just bog down, finally got pissed off & went from idle to full throttle & it died! Wouldn't start back up & I had the lovely experience of tring to paddle a 3000# boat up river for about 300 yards by myself!
I havn't been able to get ahold of my buddy yet to borrow his compression tester, so thats obviously my next step, but for now, I am going to check for spark & the other easy stuff to try to find out why it left me stranded when it usually runs great at low RPM?
Any other input would be appreciated (besides compression test)
I'm getting ready to bring this this thing back to the guy who sold it to me & park it in his livingroom

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

Just did a compression test, it came out between 113 & 117 across all 4 cylinders. I know that is low, as the manual specs 155 - 165, but is it low enough to be the cause of my problem?

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

Bump - need to know if its time for a rebuild

 

[szuwar]

Re: need help with OMC 2.3 liter

ha its funny , cause i have the same problem , and i just put in a brand new engine , rebuilt head ,block , starter , all except the carb , now its in the marina and mechanic is trying to find a problem. At the same marina, the mechanic had the boat to tune engine change oils and said that boat runs perfect (on muffs) all i need to do is go on the lake ,so i did and 100 feet later i stalled ,the more throttle it starts to choke and dies. Any ideas

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

Sounds the same as mine, except for your compression is probably where it is supposed to be. If you go back through the posts in this thread, you can start eliminating a few possabilities such as fuel starvation, timing ect.
Still waiting to find out if I need to rebuild, hopefully someone chimes in soon, as I want to take the boat out for fathers day.

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

Bump - getting ready to bring it to the marina & have it fixed at $80 an hour!
Could my prob be low compression? Runs great on muffs, barely runs in the water. 113 - 117 across all four cylinders

 

[Shadow66]

Re: need help with OMC 2.3 liter

Man, One cannot underestimate cleaning those damned fuel filters. I was having this issue and did all you have done and way more. Then I found the filter in the carb, another in the fuel pump and the another place to clean in the tank trap and valve as well as the obvious fuel/water separator and WALA! Ran unbeleivable yesterday!

New damn boat.

 

[prdmetalworks]

Re: need help with OMC 2.3 liter

The spin on filter is brand new. Just to rule out any obstructions in the tank, I ran out of a temp tank with fresh fuel, I never thought about the fuel pump filter, I will check that when I get home. At this point, I am suspecting the low compression numbers, just waiting on a confirmation from someone that knows what they are talking about. I have talked to a couple of local marina's, and they all tell me to bring it in, pay us $90 an hour & we will let you know what it is! I am ready to bring it to a marina at this point, but I want to rule out compression first, as I have rebuilt quite a few motors & am more than capable of doing the job if that is what is required. I know that 113 - 117 compression is low, but is it low enough to be causing my problem?
I am going to check the fuel pump sceen & timing when I get home, and if I can rule out compression being the culprit, then it is time for the marina.

 

[Gary H NC]

Re: need help with OMC 2.3 liter

Those compression numbers are low....tired engine,
My first thought would be to remove the head and have a look but i doubt its a head gasket being all 4 cylinders are low.
I would check those other fuel filters just for the heck of it.