New carb or rebuild

[redneck joe]

For those of you following the drama, I've had some isssues with the quality of the work from a shop I've been using for a few years. Back on the water thanks to a new guy and no issues for the three days we've been out save one small issue.


Had running issues after shutting down when hot. After a complete cool down all is ok. Last shop took it in and changed coil and about everything that could be a problem. I think i had a thread on here about it. The week they told me they rebuilt the carb it ran great for the couple weeks left in the season. Fast forward to June ish and the coupler gave the ghost and found my new mechanic. All good on the extensive repairs he completed however the 'carb' issues are starting up again this weekend. Not as bad as before but the same issue.


So can a carb be rebuit well enough for a few months or can a few months of sitting on a half assed rebuld restart the issue or .....


My ask..... spend a hundred on a rebuild and hope it is the issue or spend a few hundred on a new carb and hope... I'm leaning to new....

 

[Baylinerchuck]

I ordered a remanufactured one from National Carburetor for my 4.3L. Most of the items I would want to replace in this 4 bbl quadra-jet don't come in the standard kit such as power jet, primary and secondary needles, and main jets. Also in order to clear one of the primary circuits, I would need to drill a plug. The reman carb comes with a decent guarantee, and is just over $200.00. A no brainer in my book.

 

[stonyloam]

If you compare a boat carb to an auto carb, for ware and tear, the boat carb should last just about forever. Think about it, in the first 10,000 miles a auto carb sees more throttle changes than you would see in a boats lifetime. Problem is a boat carb sits idle for six months or more every year and that is not good. A proper cleaning and rebuild should bring it back to near new condition.

 

[redneck joe]

Having almost no knowledge of carbs, would floats be something that would get done in a rebuild and or would that be a part that would go bad on a 40 year old boat of unknown, but probable light use over those years?

 

[stonyloam]

The floats themselves should be OK, unless they develop a leak. The needle and seat (valve that the float controls) are usually replaced, along with the accelerator pump and gaskets. Mostly it is just making sure everything is clean and all of the passages are open and the float is set correctly. The Mercruiser manual has a very detailed step by step rebuild procedure. Besides anyone with "redneck" in his name ought to be able to rebuild a carb

 

[boatman37]

rebuilding a carb really is pretty simple but if you are going to pay somebody $200 to rebuild it for you then i would just buy a reman'd one. i always replace the float when doing them. its only a $5 part, why not? and a boat carb is even easier without having to deal with the fast idle cam, etc.
the biggest thing is making sure it is clean.

 

[Rick Stephens]

My only issue with buying a reman is it can be calibrated to a different engine configuration than yours. Having your carb rebuilt means you get what came out, back in. Same applies to a new carb, has to be calibrated to your engine.

 

[putback]

Boatman gave you the best carb advice you'll ever get, CLEAN. You can change every part and gasket in your carb and waste your $$$$. It needs to be disassembled stripped and every circuit cleared. Over the years they clog up. Best thing I've found to do the job today is Sea Foam, EPA nixed most we used back in the day.Soak the striped air horn, bowl assembly and throttle plate in a pan of seafoam, blow through every circuit with compressed air. If you use things like tooth picks or wire brushes in the corners and crannies beware of pieces left behind. Mikes carburetor has complete kits and videos online that make it simple. You"ll do a better job that the previous shop because you take the time when its yours. Useful tool, cheap fold up torch tip cleaner set to get in the small spots.

 

[Pete104]

Mikes carburetor has complete kits and videos online that make it simple.

Who's Mike?

 

[Scott06]

Google Mikes Carburater shop...mike is the owner sells kits and rebuilds carbs.

 

[redneck joe]

Poking around the net on this and went to suggested miles carb shop, found a mention of a thermostat in the carb. Found a Rochester manual and in reading thru it there is mention of a 'hot idle compensator'. Is this the same thing?

Reason I ask is if it is failing, the description of issues in the manual is 99.9% the issue I am experiencing which is runs fine from cold to warm to up on plane and running hotter for (so far) up to two hours. Come off plane and idle into cove / marina and sputters and stalls out. Only gets better when engine is almost completely cooled off. Can't get bast the bad idle to get back up on plane.

Only difference between this time and last year when I paid to have a rebuild is it takes less time to cool off as it is running cooler with the new Alpha stuff on and installed properly. (pretty sure I have the t-stat out as i'm only hitting 110 -120 degrees). It did work fine the couple times I had it out last year.


So question is this - would that be a part of a rebuild kit? I have searched a few and does not appear to be an included part.

 

[NHGuy]

If your carb is clogged up in one year you could easily have dirt and crud in your fuel system. So clean that while doing the carburetor.

 

[putback]

You got me swinging, never found a thermostat in a carb that I've seen, but I surely haven't seen em all. You may have an electric heating element on the outside of the carb to hold the choke open. Actually the above description sounds like symptoms of flooding. Especially considering the carb has been apart. Two likely causes. #1, the choke is not fully open at operating temp. You start it cold no problem, Bring the RPM's up to operate and intake vacuum holds the choke open, drop RPM's to near idle when warmed up the choke closes floods & stalls. Engine cools process repeats, the fix, adjust the choke to specs.? Also if your carb has no electric heating element to open the choke it depends on engine temp to do the job, 120 degrees probably is'nt enough. A thermostat will bring the engine temp up to around 150 degrees. You can start it, clip or wire the choke open take it for a test run. That should tell you if the choke is the problem....#2 Float & needle and seat valve. Very common problem for flooding at low RPM. Very common after a rebuild that the float is set to high. It can't completly shut off the incoming gas flow and drizzles gas into the intake causing the symptoms you describe. Float set to high carb floods at low rpm, set to low the engine is starved for fuel at high rpm, Has to be about right. Only way to check that potential is to remove the carb, take off the airhorn {the top} manually raise and lower the float and observe if the needle valve functions properly.Slide out the hinge pin to remove the float, pull out the needle valve, inspect the tip for defects, remove the seat & check for debree or burrs. If good reassemble and set the float to specs. Fact is for less than 50 bucks you'll have a quality kit, specs, the info you need and a device to set the float correctly. And just buy a new float with the kit. Pretty common for a shop in a hurry to reinstall the original float that is fuel soaked & over weight, then to compensate for the "heavy" float they set it a bit high thus causing the symptoms you describe.

 

[redneck joe]

 

[redneck joe]

 

[redneck joe]

 

[redneck joe]

You got me swinging, never found a thermostat in a carb that I've seen, but I surely haven't seen em all. You may have an electric heating element on the outside of the carb to hold the choke open. Actually the above description sounds like symptoms of flooding. Especially considering the carb has been apart. Two likely causes. #1, the choke is not fully open at operating temp. You start it cold no problem, Bring the RPM's up to operate and intake vacuum holds the choke open, drop RPM's to near idle when warmed up the choke closes floods & stalls. Engine cools process repeats, the fix, adjust the choke to specs.? Also if your carb has no electric heating element to open the choke it depends on engine temp to do the job, 120 degrees probably is'nt enough. A thermostat will bring the engine temp up to around 150 degrees. You can start it, clip or wire the choke open take it for a test run. That should tell you if the choke is the problem....#2 Float & needle and seat valve. Very common problem for flooding at low RPM. Very common after a rebuild that the float is set to high. It can't completly shut off the incoming gas flow and drizzles gas into the intake causing the symptoms you describe. Float set to high carb floods at low rpm, set to low the engine is starved for fuel at high rpm, Has to be about right. Only way to check that potential is to remove the carb, take off the airhorn {the top** manually raise and lower the float and observe if the needle valve functions properly.Slide out the hinge pin to remove the float, pull out the needle valve, inspect the tip for defects, remove the seat & check for debree or burrs. If good reassemble and set the float to specs. Fact is for less than 50 bucks you'll have a quality kit, specs, the info you need and a device to set the float correctly. And just buy a new float with the kit. Pretty common for a shop in a hurry to reinstall the original float that is fuel soaked & over weight, then to compensate for the "heavy" float they set it a bit high thus causing the symptoms you describe.

Only has issues at low RPM, zero issue at high until I slow down in fact best top end speed this weekend after the gimble/sterndrive work. I'm going to replicate issue on the water hopefully tomorrow morning and spray carb cleaner in there as it starts to bog at low rpm and see if it is a rich or lean issue.

 

[redneck joe]

Went out for a couple hours yesterday. Ramp parkinglot was empty except one car and this dude was walking around playing guitar and singing. He went out with me. Quite interesting but that story is for another thread



As usual, ran perfect until i came off plane and at hull speed after about 1 to 2 minutes started sputtering then died. I can restart at full throttle and it runs for a bit then same.

 

[redneck joe]

Went out for a couple hours yesterday. Ramp parking lot was empty except one car and this dude was walking around playing guitar and singing. He went out with me. Quite interesting but that story is for another thread



As usual, ran perfect until i came off plane and at hull speed after about 1 to 2 minutes started sputtering then died. I can restart at full throttle and it runs for a bit then same.

I did what my mechanic told me and spayed carb cleaner in and it died.


Hot carb:


http://s1374.photobucket.com/user/j...Uploads/20160908_1541410_zpsca6t0icv.jpg.html

 

[redneck joe]

So i cannot replicate in the driveway and temps are same and warmer and cannot get it to stall out. Thoughts? Going to try to sneak to the lake a couple hours next week.