Carb: rebuild or just clean the crap out of it?

[mary]

Hi all,

My initial excitement of finally completing enough repairs to get our boat operational was quickly interrupted by the carb acting up. I was fairly certain that it had some crud in it and after looking inside, I can hardly believe the thing ran at all!

Ken suggested on the phone that I "spray the living bejeezus out of it" which I have done, followed by soaking in gas overnight and am about to continue spraying (can't call Ken to ask about rebuilding since its the weekend ).

I got a rebuild kit since it includes the gaskets, but is it good enough to just clean, replace gaskets and be on my way? It worked well besides the clogging and I'm intimidated by all the tiny adjustments required when removing and replacing things.

Anyone have pro tips about how to remove/replace the float to replace the gasket? Looks pretty straightforward, just remove the pin?

THANKS!

[Marty Levenson]

Go for it!

"Anyone have pro tips about how to remove/replace the float to replace the gasket? Looks pretty straightforward, just remove the pin?"

Yes - remove the pin - it is very easy to do. Slightly awkward getting the float through the gasket while dis- or re-assembly. Just be gentle.

Compressed air after soaking helps a lot. If no compressor you can buy a spray can of air. I like to soak, poke with various wires, soak again, then use air. Eye protection!

[lat 64]

Mary,

Yes, Don't be intimidated. Put it all on the kitchen table with an open time frame and go though it slowly with some Bach cello music on the hifi.

Do push a small wire through the passages that are the ports for idle circuits and such. A soft wire like copper is better to not scratch things up.
Blow air through these passages too. Not high-pressure, just puffs.

Use a flat surface like kitchen counter to candle it. That is; set the flat gasket surface against the counter and lay your eye close to see if much light cones through. Then make it flat if ness.

Marty is right, float adjust is easy. 99.9% of all carbs use a setting that just requires putting the float level with(parralel to) the gasket parting line of the top/bottom halves of the carb.
A carb float does the same job as a toilet tank fill valve. I hope that image helps

If it's the old-style, then the main jet needs adjusting after installation but you can do that too.

Cheers,


Russ

[ndutton]

12 bucks and change and you can download an MMI how-to carburetor video.

[Al Schober]

The filters are supposed to keep crud out of the carb. 'Supposed to' is the key - the carb is at the end of the fuel system, and guess where stuff ends up.
Learning to clean a carb is not hard - cleaning out just the main jet and the float valve will get it running. May not idle well, but it will get you home. A quick and dirty cleaning can easily be done on board.
A flooding carb means the needle valve isn't closing. A carb that needs full choke to run means the main jet is clogged. Main jet can often be cleared just by removing the plug and running a wire through it. With an adjustable main jet, you can often clear it just by running the jet closed/open full/closed/open. During the first closing, count the turns - final opening to be the same.
Nothing beats having a spare carb sealed in a plastic bag ready to go. Swap them out then take the dirty carb home for a good rebuild on the workbench. Using studs and nuts makes the carbs much easier to change than the usual bolts.

[JOHN COOKSON]

Try following the exploded parts diagram as you take the carb apart.

TRUE GRIT

[Chris Simenstad]

Give the whole fuel system attention!

Having just gone through an episode of bad gas/crud in the carb, do yourself the favor of siphoning some gas off the bottom of your tank, and look at it closely. Is there water or gunk? If so, cleaning the carburetor won't be enough, as it will just clog up again with the crap from the tank.

It will be 100% worth your time and piece of mind to just empty the tank, and start with fresh gas treated with Marine Sta-bil. I siphoned my tank from the vent tube port, which is on the starboard side, so I heeled the boat to get as much gas as I could.

Be sure to swap out old fuel lines, empty the sediment bowl if you have a mechanical fuel pump, and change your water separating filter and polishing filter (or add them if you do not have them).

in the end I bought a new carburetor so I could rebuild the old one at my leisure, and then have a spare. With the new one and fresh, clean gas, my engine has never started so easily and run so well.

[mary]

Thanks, everyone.

We bought this boat about a year and a half ago and emptied the old fuel then.

[alcodiesel]

Bach cello music on the hifi.

Ahh Russ, I concur with the Bach. It's "hifi" that got me. Thanks for the blast from the past.

[lat 64]

Bach cello music on the hifi.

Ahh Russ, I concur with the Bach. It's "hifi" that got me. Thanks for the blast from the past.

Bach and Hendricks, John and James, timeless; but technology, not so much IMHO. I have so much vinyl I could open a store but the old turntable is rather slow these days.
The sampling rate for cds(cd "quality") is is tolerable; but OMG, MP3? May as well get out my Kenner Close-n-Play from kindergarten.

[sallyjane823]

Mary - Did you end up rebuilding the carb or just clean it?

[Marineee]

Were you able to rebuild the carb? any updates?

[mary]

Mary - Did you end up rebuilding the carb or just clean it?

Were you able to rebuild the carb? any updates?

@sallyjane823 and @marineee : sorry I missed these posts. I pulled the carb apart, cleaned with carb cleaner and compressed air, replaced the gaskets and re-installed it. Now the RPM is running insanely high, so I wouldn't say I fixed it! Will post more in my more recent thread when I get it sorted. Back to work until next weekend, so I'll work on it then.

[sastanley]

@sallyjane823 and @marineee : sorry I missed these posts. I pulled the carb apart, cleaned with carb cleaner and compressed air, replaced the gaskets and re-installed it. Now the RPM is running insanely high, so I wouldn't say I fixed it! Will post more in my more recent thread when I get it sorted. Back to work until next weekend, so I'll work on it then.

Uh oh...might be an air leak..don't worry we'll help you get it sorted!!

[MLW]

Pitting

May have nothing to do with OP or it may so YMMV. Mine wasn't running when I bought it and I planned on rebuilding carb. After rebuilding motor and taking down carb, castings were pitted really bad around throttle plate. I foolishly put it back together and couldn't get a low speed idle. Bought a new carb and money well spent. Moral is, inspect casting and make sure you can blow through passages before buying rebuild kit.