Boat Motor

[EEngel]

Hey Guys,



I have a quick question on a long post. Just looking for some new ideas.



I have a 87 starcraft with a OMC Cobra 120hp. It's a chevy 2. 5 liter (153 I think).



Last year it ran great. I winterized it and left her sit with a completely empty tank of gas and empty carb (ran it till she died).



I pulled it out this year and it revs up to 2200 rpm great, then bogs out and dies.



I replaced the fuel pump, all the fuel lines, fuel filter, plugs, wires, cap, rotor, carb filter, and the water seperator.



It still dies at 22-2300 rpm.



Guy here at work said it's the timing. How could it change just sitting over winter??????



Any other ideas?

 

[big barney]

Try this website. http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi

 

[bighammer]

The first thought that came to me was a stuck float in the carb. I have an old Farmall that I used to shut off the fuel line and let it run til it quit. If I re-started it after a long time, (month or more) I'd get it to start but then it would run so slobery rich it had no power and quit. But then it wouldn't start because it was flooded.



The timing is easy to check, but I wouldn't figure it had changed over the winter. Any hints on if it's flooding or leaning out?

 

[EEngel]

Link

big barney,



Thanks for the link.

 

[EEngel]

Lean / Rich

bighammer,



I'm really not sure what the heck it is doing.



Today I checked the floats, replaced the points, and replaced the coil. Still the same problem.



I finally got ****** and brought it to a repair shop a few miles away.



He can have the headache.



Thanx for the tip on the carb, I will remeber that next spring.

 

[crabman]

BOAT=BRING OUT ANOTHER THOUSAND

crabman

 

[EEngel]

$$$$$

Crabman,



I couldn't agree more. Seems like all the seasonal toys are just plain expensive. Not only the purchase but the seasonal maintainance.



Sleds, ya nice on those rare years that the snow has been good enough, bikes, nice for those 3 months of road construction here.



Now the ram, all year round she's good. No oh-craps when you go to start her.

 

[Plazman]

Ok guys, I had a 120hp OMC 18ft Reinell, with the same problem. It would do the same thing after sitting around for a while in the summer. did most of what you have done, but after spending lotsa $ ,guess what!! try checking the gas tank VENT, I had those nasty wasps pokin' mud in the vent. Take a good look at the whole vent system also, sometimes the vent line can collaps, it will run good for awhile then fall flat, on hot days it may run great as long as there is pressure in the fuel tank.

One last thing to check might be the pickup screen in the tank, some boats have them and some don't, varnish can accumilate there when you run the tank dry, leave some gas in it with Stabil, or some other such product, to keep the fuel fresh over time.

good luck!







" A BOAT MAKES A HOLE IN THE WATER IN WHICH TO THROUGH MONEY IN"

 

[EEngel]

Boat sucks

Plazman,



I replaced the screen in the pick-up, ran all new fuel lines, and tried to run it with the gas cap open.



Still didn't run after 2000 rpm or so. Finally got sick of listening to the wife bi***, so I brought it in.



Guess we will see how much damage to the wallet and pride is done.



Thanx for the help.

 

[mainer]

Put mystery oil in every tankful.

 

[EEngel]

mystery oil

What the heck is mystery oil???

 

[EEngel]

Update

Boat repair shop called. He claims the carb is screwed and it needs a rebuild.



Only problem is that he can't seem to get a bowl, jet and the rebuild kit. Claims $350 for a remanufactued carb.



This is just a common Rodchester 2 barrel carb off a chevy motor.



Anybody have a good link to used or rebuilt carbs?

 

[Plazman]

I would question the need for a new or rebuilt carb, unless there is mechanical damage or severe wear on the one you have, I have seen this before, repair shops want the easy way out in hopes they hit it right, but chances are it won't fix it.

A 2 barrel Rochester is one of the easiest carbs to rebuild, you can do it your self. Just what is the shop saying that is screwed, ask for details before springing for a $350. 00 carb, I have seen many "rebuilt carbs" that are worse than the original.

Also I don't think the "bowl" is replaceable on a rochester, so that statement would lead me to suspiction, it's part of the entire casting!! All of the important components are however replaceable, needle and seat, float, gaskets, jets and such.

I would try and do it yourself first, just get a rebuild kit from a dealer, (maybe a diiferant one than you are using now) and just do it, get a buddy to help, if your uncomfotable with a carb repairs, read the instructions carefully and follow the procedure thru.

I spent a couple weeks at our local GM training center, getting certified on Rochesters, they are a very good carb and will last for many, many years. Of couse that was years ago!!! but things haven't changed that much.

Some questions i would like to ask is does the engine starve for fuel went not loaded? i. e. out of the water, does it just stall out or does it give up eradically,suggesting an ignition problem. When you approach the point where it begins to give up, does it surge?

I would check the fuel delivery at the carb too,to see if the fuel pump and all associated lines are working, check for volume as well as pressure when idleing. attach a fuel ine ,and route it out of the boat before doing this tho so as not to start a fire, and keep an extiguisher handy just in case, course that would solve all the problems, wouldn't it?

Let us know what you find!!!

 

[Texas Diesel]

Clean the main jet, it's gummed up. Forget the replacement just dissamble and clean it.

 

[TGreschuk]

Originally posted by EEngel

Boat repair shop called. He claims the carb is screwed and it needs a rebuild.



Only problem is that he can't seem to get a bowl, jet and the rebuild kit. Claims $350 for a remanufactued carb.



This is just a common Rodchester 2 barrel carb off a chevy motor.



Anybody have a good link to used or rebuilt carbs?

He probably can't rebuild it, and is looking for the easy way out in ordering a remanufactured carburetor (probably one that has been on a shelf for 3 years, all dried out, and will leak like a sieve when he puts it on) Contact a local carburetor rebuilder shop (automotive) and they will probably overhaul the one you have and make it work like a dream for $50 plus the kit.

Trent

 

[EEngel]

Boat update

Well, I got angry and took the boat back.



Went to a local repair shop and had him take a look. He said there was water in the carb over the winter and it had coroded the heck out of the accelerator pump, float, and power piston. I got the part numbers from him (hey they do exist, contrary to the other clown's comments). I called and they nolonger make the rebuild kit and they don't sell the power piston seperatly.



Well, I went on the net to a rochester race carb company and he had both. I probably paid a bit more for the parts, but the frustration is over.



It was $38 for the rebuild kit and $25 for the power piston. I grabbed an ultra-sonic cleaner from work today, so I will clean all the crap off the bowl and let the local guy rebuild the carb for $65.



So, I have $128 in it instead of $350 for the remanufactured carb.



Thanks for all the help guys. Next boat will have a diesel... ...

 

[mainer]

Marvel Mystery Oil - it comes in a red can. Get it at any auto parts store or Wal-Mart. It's been around for several generations at least. When I winterize a boat motor, outboard or inboard, the last thing I do is squirt Mystery Oil into the carbs until the engine stalls or almost stalls. DO IT! Also, a tablespoon of the stuff per gallon of gas or diesel will keep things going well. Don't worry if your engine is 2 cycle or 4, just use this stuff. If you can afford to, put it in your crankcase too.

 

[EEngel]

Oil

Mainer,



Thanx for the info. I will get some and give it a try. I will definitly be flooding the carb out this year.

 

[EEngel]

It's back with more problems

Well, the carb sits on the rebuild table.



The Power Valve is toast.



I have called about 30 places now and nobody can get me a part.



HELP!!!!!!!!!!!



It's a 1986 chevy 2. 5 liter (120hp by OMC corba).



Rochester 2 barrel carb. Here are some pics of the power valve.



Where can I get one!!!!!!!!!!

 

[EEngel]

another pic

With scale in CM.