Trouble when giving it the gas!

[medic]

Ok...here goes...sorry in advance for the long post. <br /><br />Bought this boat from my brother-in-law. It has an inboard OMC 2.5 liter. 1982 Model MHP Advantage. Took it out on the water today. Pushed away from the dock. Fired it up and went about my business. Everything working ok at that time. Out on the water for a little while and things start to happen.<br /><br />Sitting out on the lake, I go to start it up. Starts fine. No choke needed. It will idle. Just now paying attention to the fact that idle is at 2000. A little fast. Have not turned it down yet. But that is a minor problem. When I push in the button on the throttle lever to put it into gear, it engages but then I have a rough time increasing the throttle. Most of the time it will just die and I have to repeatly start it again and again. If I am lucky, I can open it wide open and it will start moving then I bring it back to a cruising speed. Was thinking bad gas, since it had been sitting since last summer, but I had just put fresh in it. If I have tried several attempts to start it, I have a hard time getting it to idle...but it will.<br /><br />If I am cruising and I pull the throttle back to neutral, sometimes it will die. Also, when I am cruising and I open up the throttle, everything is ok for just a few seconds then it dies out. Like it is flooded.<br /><br />Any ideas on what is going on here? I am thinking plugs, air filter, maybe plug wires too. <br /><br />Thanks to all,<br />Medic

 

[snapperbait]

Re: Trouble when giving it the gas!

I'd get the idle down to around 750rpm if you can and put a timing light on it to make sure the base timing and advance is correct...<br /><br />I'm thinking carb rebuild because if it sat with gas in the carb since last summer it's probably full of crud... Gas leaves a "varnish" which gunks up the tiny passages in the carb.... <br /><br />And complete tune up being plugs, cap & rotor, points & condinser, PCV valve (if equipped), clean the flame arrestor, and whatever else I'm leaving out cause my brain just pooped out.... <br /><br />Oh Yeah! A service manual would be a wise investment....

 

[medic]

Re: Trouble when giving it the gas!

Good call on the carbs. Same thing happened to a motorcyle I bought. All the trouble was carb. related. Payed for the first one. Done the second myself. How hard is it on a boat?<br /><br />Now if I can just find a manual...

 

[snapperbait]

Re: Trouble when giving it the gas!

Carbs are no prob... Get the complete carb rebuild kit for whatever carb you have and follow the destructions in that all important service manual... Some carb kits come with complete instructions as well...

 

[medic]

Re: Trouble when giving it the gas!

Until I am able to get a manual, would anyone have a copy of those pages or know of a link somewhere for some guidance? The engine itself is a 2.5 L inboard OMC 4 cyclinder.<br /><br />Thanks.

 

[medic]

Re: Trouble when giving it the gas!

Went and looked at some things today and was pleased. The plugs looked to be in new condition. Regapped them anyway. Checked the plug wires and checked the oil. No problems. Points and rotor are new too. I think. Started it up for a few seconds and it idled perfect. Only thing left is the carbs and those floats.<br /><br />Thanks to all.

 

[snapperbait]

Re: Trouble when giving it the gas!

Medic... Just a thought here... Check your local library... They might just have the service manual you need... Might hold ya over for a few days..

 

[medic]

Re: Trouble when giving it the gas!

How often do we forget the 'ole library. Thanks. When I was working of the boat today, I looked on the carb for a name and saw "GM" Does that sound like a marine carb. manufacturer? It also said "2 jet" below it.<br /><br />I also found a couple of omc carbs on ebay. <br />What do I need to know in order for these to fit?

 

[snapperbait]

Re: Trouble when giving it the gas!

Sounds like a General motors 2bbl Rochester, probably a marine version... Very common and EZ to rebuild too...<br /><br />Could probably find instructions on how to rebuild that carb in any book that covers GM vehicles with carburators like 1960's thru 1980's cars and maybe some small trucks...

 

[medic]

Re: Trouble when giving it the gas!

This may sound like a stupid question, but is it acceptable/possible to get a carb. kit for this thing at an auto parts store?

 

[snapperbait]

Re: Trouble when giving it the gas!

Yes.. The internal parts are the same but the jets and metering rods may be of differnt specs. I dunno... If you can, try NAPA... Not many folks know but NAPA has marine parts too, and some other auto parts store can cross reference marine engine parts.....

 

[medic]

Re: Trouble when giving it the gas!

Snapperbait,<br /><br />The only numbers I found on this carb. are "17059056". Underneath it were 062 9 1".<br />I went by Advance Auto and they typed in the number and got a hit on "GP Sorenson" rebuild kit, but they cannot get it.<br /><br />I have looked and looked on the net and can find nothing. I am pretty sure I got the number right, but am getting no hits. What is the deal?<br /><br />Medic

 

[medic]

Re: Trouble when giving it the gas!

<bump>

 

[rabidfish]

Re: Trouble when giving it the gas!

Somewhere on that engine is a model number. Give that to an OMC dealer. He/she will be able to get you the right kit. Contact me directly if you have no luck.

 

[Bondo]

Re: Trouble when giving it the gas!

MFG.# "17059056". <br />NAPA # 18-7608 Complete Reman Carb.....<br />NAPA # 18-7071 Should be the carb kit for it....

 

[galaxy]

Re: Trouble when giving it the gas!

Medic, Just re-built my Rochester 2-jet carb. Just pay close attention during disassembly to be sure you assemble the same way. You'll also get more gaskets than you'll know what to do with. Just make sure you match them up with the old...assuming the old ones are original. Just clean it out very good with carb cleaner or parts cleaner first and blow compressed air thru all passages. Putting new parts in is a waste of time if you don't clean it spic and span. Good luck.

 

[MrDumb]

Re: Trouble when giving it the gas!

Just a thought you may want to change your fuel filter/seperator?

 

[medic]

Re: Trouble when giving it the gas!

You guys are awesome and worth your weight in gold. This is what the forums are all about. Before I forget, thanks to each one of you for your help. <br /><br />Snapperbait for leading me in the right direction. Rabidfish, for the extra help. Bondo, how did you get those numbers. I could not find them on the web. Even typed in the numbers on napaautoparts web site and no luck. Galaxy, did you have any problems? The only carb I ever had somewhat apart was my motor cycle.<br /><br />Here is what I found today. I went to a local autoparts store and gave the guy the model number off of the carb. He can get the kit for about 16 bucks. Also called the local boat dealer/service center and he used the year, make and liter of the engine to get the kit part number. He has it for 22 and some change. He also said there is no difference in the carb/kit being a marine or auto. Is this so? Autozone can get the kit for almost 20 bucks and they also have a manual for Rochester carbs. 1, 2 and 4 barrel. I looked at it briefly and did not see an exact picture of my carb. But I think it will work anyways. The carb is listed between 1972 and 1986 year models. (got that info from the service center) <br /><br />As soon as I can get the parts, I believe I will tear into it. Can't see paying the service center 50 bucks an hour...yet. lol<br /><br />Thanks again and I'll let you know how it goes. I am sure there will be more questions.<br /><br />Bill<br />(medic)

 

[medic]

Re: Trouble when giving it the gas!

MrDumb,<br /><br />I am a new boater. I understand what the seperator does, but where is it? Is is part of the fuel filter assembly?<br /><br />medic

 

[galaxy]

Re: Trouble when giving it the gas!

I've re-built several auto carb's... it's not that hard. Just take your time. Just take notes of what goes where. The diagrams you will get with the kit is so widespread and sometimes difficult to decipher. All the parts will have a line going to the location inside the carb but there are so many and the printing of these diagrams are not very good quality. I wouldn't use any gasket sealer either. Don't need it. That particular two barrel is pretty simple. You'll get a couple of gaskets for between the top plate and main body. Be sure and use the one that is open where the float is. Or "cut out" I should say. Also be sure and get your float levels correct. You should get a paper guage with the kit. Trust me.... take your time and do it right the first time. Good luck