Carb help

[tkilvinger]

I recently "refreshed" my carb with a rebuild kit( 2 BBl rochester I believe on an OMC 2.3L), and I thought I had everything back in working order, when I try to control the throttle to make sure the linkages are all back together correctly, the main butterfly valve won't open fully. At a full throttle opening(with the boat not running) the valve opens only 1/4 of the way...I remember this fully opening before...for some reason I remember there being a spring on the linkage (where the two brass rods connect) but I cannot find it anywhere. Does anyone have a picture or can direct me to a picture of their carb so I can compare? Thanks

 

[Haut Medoc]

Re: Carb help

Welcome to iboats......
I can't help you, but I'm sure someone can...
If you could post the year & possibly a pic, it would be helpful.....​

 

[tkilvinger]

Re: Carb help

Thanks, I'll get a picture of it when I get home. I hope it is something simple that I am missing.

Secondary to this...We've owned the boat for 3 years, only run it a handful of times. It is a 1985 Renken OMC 2.3L Cobra The boat ran pretty well the first year, got on plane easily, no problems really...Last year we took it out one day and it worked fine out of the harbor, got out into the bay and started to get on plane then all of a sudden it seemed as if it lost power, boat will idle along fine and will drive with maybe 1/8 power...so we had to limp back to the dock. Anytime I tried to get it on plane, it would buck (almost as if it was fuel starved) but then go back down and idle fine. I have checked the fuel pump, check valve on the tank, changed plugs and just recently rebuilt the carb. I want to get the carb rebuild issue buttoned up first before I start it up and start to troubleshoot the electrical.

 

[Bondo]

Re: Carb help

(almost as if it was fuel starved)

Ayuh,........

I Think that's the Issue Too.......

 

[tkilvinger]

Re: Carb help

Here are some pictures guys, best I can do for now, pictures are of the backside of the carb (2 bbl. rochester) looking at the linkages, one is with the throttle open all the way (valve only open a 1/4) Does anything look wrong??

Full throttle

 

[Buttanic]

Re: Carb help

I may be wrong but I think you are confusing the main trottle butterflys with the choke plate. This is a choke adjustment problem not throttle linkage problen

 

[tkilvinger]

Re: Carb help

Sorry, had the wrong verbage then...either way, should that choke plate be nearly vertical on full throttle? Wouldn't this still be linkage related? I never adjusted the choke, just replaced the gaskets and internal workings of the carb.....(i.e. float, filter........)

 

[Coors]

Re: Carb help

Why are hose clamps on the linkage?

 

[delsol]

Re: Carb help

i had the same boat 18' from hell. i had the same problem as you ran great then stady slow. i thought carb. f/p filters. it was a bad tank of gas. not saying its not the carb. but the tank was in the back and easy to clean. hope your stringers are good as mine i replaced. but i got alot of ocean time off west palm beach fla . catch fish and having fun. just my 2 cents.
bob

 

[tkilvinger]

Re: Carb help

Beats the hell out of me, that's the way we got the boat....for free by the way. If I loosen the hose clamps, the linkages at the end of the rod loosen away from the threads and fall of the linkage. Probably not the correct rod ends I would suspect. The seemed to be plastic not metal. I never adjusted them when I took the carb apart. Does anyone have any idea, or at the very least can point me in the direction of a blown up schematic or something that I could check against? I'll even settle for a picture of a 2 bbl carb just like it!

Edit:

I just received a PM form Bluto stating :"The valve on top is your choke. It opens with engine temperature NOT engine speed" So should I assume I actually have everything hooked up correctly and that the choke valve won't open until the motor is actually running??

 

[Limited-Time]

Re: Carb help

The choke should "pull off" as the engine comes up to operating temp. This can be verified by running the engine on the trailer with the muffs connected.

 

[bjcsc]

Re: Carb help

If you hold the choke open, (engine OFF), and cycle the linkage you should be able to see the throttle opening full when you look into the carb. When you start your engine, your choke should open fully (nearly straight vertical) within a few minutes, actually way before you get to operating temp. If it does not, it needs to be adjusted so it does.

 

[Gary H NC]

Re: Carb help

Do like the guys tell ya,hold the choke open and look down the carb.the lower plates should be vertical at full throttle.Thats a hot air activated choke,it will stay shut like that untill the metal tube warms up..

 

[tkilvinger]

Re: Carb help

Thanks for all the help guys...I'm going to give it a try this weekend...hopefully the carb rebuild solved the original problem.

 

[tkilvinger]

Re: Carb help

So to give an update. I was able to get the boat started and the boat will idle now. But if I try to give it more than a 1/4 throttle or if it is given throttle to fast...it starts to choke out and wants to die. If pushed all the way to full throttle, the boat sputters at no more than a rough 2k RPM. Can someone verify that I at least have the sparkplugs correct....

I tried removing one by one while the boat was running at a little above idle, this had no effect. Is this still a fuel problem? The sparkplugs, wires, cap and rotor are all new. Would a bad fuel filter (water/fuel seperator) cause this problem? As far as I can tell the fuel pump (mechanical) is working quite well. Any ideas?

 

[Wotknot]

Re: Carb help

So to give an update. I was able to get the boat started and the boat will idle now. But if I try to give it more than a 1/4 throttle or if it is given throttle to fast...it starts to choke out and wants to die. If pushed all the way to full throttle, the boat sputters at no more than a rough 2k RPM. Can someone verify that I at least have the sparkplugs correct....

I tried removing one by one while the boat was running at a little above idle, this had no effect. Is this still a fuel problem? The sparkplugs, wires, cap and rotor are all new. Would a bad fuel filter (water/fuel seperator) cause this problem? As far as I can tell the fuel pump (mechanical) is working quite well. Any ideas?

You betcha it will. Dump the contents of the separator into a clear container and look for water/trash. By you asking, I assume it needs replacing anyhow.

 

[tkilvinger]

Re: Carb help

It's basically the last thing I have yet to replace. So I'm really hoping that it is the problem...after that I am stumped. Anyone know if this is a "common" filter I can take to the local shop or soemthing that needs to be ordered. I guess it is true what they say about boats...giant fiberglass holes in the water that you throw money into!

 

[Haut Medoc]

Re: Carb help

Any West Marine should have it......
The water separater is the first thing that you should replace when you suspect a fuel problem.......
​

 

[tkilvinger]

Re: Carb help

Well I took the filter out, and it was "saturated" but there was no garbage or build up that fell out of it....I'll replace it anyway, but it doesn't look bad really.

 

[marunr]

Re: Carb help

Have you done a complete tune up? I had the same problem with the same engine 2 years ago and spent several weekends working on the carb, because I had just done a complete tune up for "summerization", only to find out I had been given a defective condenser. I replaced that and it ran fine. It acted exactly like it was flooding out...even had black somke coming out. If you have a manual there should be a troubleshooting section for the points and condenser.