Dirty Carbs, I think!

[EJ3]

I just bought this boat and have been working on it. It sat for a while, a few months at best, but I don't know exactly how long.

1977 55hp Johnson

Here's my problem...

It's not hard to start, but it does take a long time to idle on it's own without the warmup lever engaged. Once I get going, idle speed, it wants to stall, and after a few seconds, it does! I tried just throwing it into a faster rpm right off the bat, but the stalling happens even faster. I can, however, bump the choke and it keeps it running. The gas is old, but no more than 4 months.

I think it is a dirty carb problem due to the length of time it sat and the above mentioned characteristics, but wanted to consult the experts!

I know I am not supposed to , but I reved it up on the hose ONCE and very quick&short, and there was a hesitation before going to higher rpm's.

Input anyone! Thanks

 

[Silvertip]

Re: Dirty Carbs, I think!

Step 1: Add some fresh gas to the old stuff. You have no idea if the old fuel was stabilized before storage. Better yet, dump the old stuff into your car, truck, tractor, weed whacker, lawn mower or whatever and use fresh fuel. If bumping the choke helps keep it going you have a fuel delivery problem that may be dirty carbs, bad fuel pump, air leaks in fuel lines, etc. Do the cheap stuff first and make sure you have a good set of plugs and that you have a good fat spark on all cylinders. Carb adjustments need to be made with the engine in the lake.

 

[HighTrim]

Re: Dirty Carbs, I think!

Carb probably does need a bath and rebuild. Run seafoam or BRP Carbon Guard in your fuel from now on, premixed with your oil. If it sits for a bit between uses, Stabil should also be added, but get rid of that old fuel. Will pumping the primer bulb cause it to pick up, may also be fuel pump issues.

Me and Silvertip type in unison

 

[EJ3]

Re: Dirty Carbs, I think!

Carb probably does need a bath and rebuild. Run seafoam or BRP Carbon Guard in your fuel from now on, premixed with your oil. If it sits for a bit between uses, Stabil should also be added, but get rid of that old fuel. Will pumping the primer bulb cause it to pick up, may also be fuel pump issues.

Me and Silvertip type in unison

I don't know if pumping the bulb does anything, but it stays tight. I will definetly be replacing the tank, primer bulb, and line since I already have a new one that I don't use. The fuel line that is on it now is not flexable at all, it is supposed to be but so old it would probably crack instead of bending!!! I plan on using SeaFoam as an additive once I get the carbs cleaned, I heard it is wonderfull stuff. I will get rid old fuel!!! How would I identify a bad fuel pump?

 

[tashasdaddy]

Re: Dirty Carbs, I think!

you have probably picked up carp out of the old hose, going into the carb. remove the cover on the fuel pump. center screw, the black plate comes off. careful of the gasket. there is a filter screen underneath, inspect and cleam.

 

[HighTrim]

Re: Dirty Carbs, I think!

I would start with a carb rebuild. It is something that should always be done on a new motor to you anyways, or ABOUT every 3 years. Pumping the primer bulb is a method of sorts to test the fuel pump, what you are doing is acting like the fuel pump, so if it picks up, it could be fuel pump related, like a leaky diaphragm. Dont forget to listen to Silvertips advice about the spark test, make sure you are getting a good jump on all cylinders, and also do a compression test, just for future troubleshooting, so you have a benchmark, and clean out all debris from the pump filter.

 

[EJ3]

Re: Dirty Carbs, I think!

Can carbs be cleaned without messing with the adjustment screws?

I think I have seen carb kit's. What are they? Is it a kit, like a water pump kit, that has replacement parts for the ones that wear out? And is there anything that needs replacing, routine things not broken things, when cleaning carbs?

 

[HighTrim]

Re: Dirty Carbs, I think!

This is the kit that you will need.

http://www.iboats.com/mall/partfind...gd_poid=109332&gd_row=55&**********=144940393


You might also want to look into getting yourself a manual, it will pay for itself many times over. This tutorial may also help for the carb rebuild for your first time. Good luck.

"http://www.meegsonline.com/tmd/TMDsVideoChronicle2.wmv"

 

[EJ3]

Re: Dirty Carbs, I think!

HTrim:

Thank you for the link to the tutorial, it helped! I do have a manual, a Seloc, but I am not as happy as I could be with it, but it did its job. When I took the jets out they were all junked up with a med/dark tan in color...... stuff (I don't know what is was) The float bowl had this same "stuff" in it, but clean now. I didn't use any sovlents, just used a rag wrapped around a flathead. Should I have used a solvent? I did it pretty clean though. The jets I made sure were extra clean.

TDaddy:

I checked the screen inside the fuel pump and there was some small debris in there. But I don't understand how the pump works. I don't see any moving parts or anything that would drive a moving part.


Now that I have cleaned the carbs, would it be benificial to run a full strenght dose of Seafoam throught it or would it be pointless?

 

[clemsonfor]

Re: Dirty Carbs, I think!

i would have at least used spray carb cleaner! the pump works on a vacume from the bottom cyl, behind it is a port/hole(pulseport) that goes to the crakcase and when the pistons move and create a vacume it sucks a rubber piece inside the pump back and forth (a diaphram pump like on weedeaters, saws etc.) this pulls and pushes gas into the carbs! a very simple explination but after taking one apart and looking you should totally understand.

-Nate