Excess Fuel?

[sandiegomike]

Hi, I have rebuilt my late model carbuator and continue to get what seems like excessive fuel coming in and misting up through the spark arrestor. I had another guy work on this a second time and the samething is happening. The engine does start, but "chugs." Advancing the throttle does not increase RPM. Some of the other things we have done: we have checked timing, plug wires 1, 2 4, 3, changed cap, rotor, condenser,points, new plug wires and spark plugs. We have checked compression and it is ok. We believe the issue is the carburator? The electric fuel pump is working. The floats are parallel to the carb as outlined in Moyer's service and overhaul manual. The idle pin was seated and backed out 1.5 turns.

The water pump is working and we are discharging cooling water.

Any thoughts or questions to help guide us?

[JOHN COOKSON]

Yes, It's The Carburetor

Mike
Welcome to the forum.
One scenario is pieces of KRAP in the fuel are blocking the float needle valve and holding it open and flooding the carb. Serial carburetor fixing will get you nothing but more frustrated. You need to supply the carb with pristine clean fuel.
Another possibly is the float needle valve is not sealing the inlet all the way for some reason - maybe wear or corrosion.
To prove or disprove all this clean the carburetor one more time then run off an auxiliary tank with clean fuel and see if the symptoms go away. My guess is there is KRAP in the boat's tank that is getting past the filters. Do you have a polishing filter between the fuel pump & carb? Might be something to consider if you don't.

TRUE GRIT

Edit: I presume the float drop is set correctly?

[Whippet]

Don Video

Dont mean to separate you and $12.50 unnecessarily - but Don video available through online store gives clear and concise info on carb troubleshoot. I know I learned a lot.

[Al Schober]

I went through a period of float valve clogging/staying open caused BY the polishing filter. The internals of the polishing filter were plain steel, and were corroding due to slight moisture in the fuel. And guess where the corrosion products went??
If your polishing filter is more than two years old, replace it. Avoid the months of carb cleaning that I went through.

[sandiegomike]

Thanks all. I am actually using an auxilary tank with brand new fuel as of 2 weeks ago. I also should have mentioned I have 3 fuel filters. The first one is a water separator, the second is the original can style and the third is an inline between the fuel pump and the carb. The fuel system between the tank and the carb are tight as I have a pump ball between the tank and the first filter to prime and pressurize as to check for "non tight" connections. Filters are all new in the last 3 weeks. I quit using the on board tank about 5 years ago because it is full of gunk. This is a 1968 Columbia 27.

[sandiegomike]

John Cookson "Edit: I presume the float drop is set correctly?"

I am not sure what this means. Can you explain a bit. I have not seen float drop anywhere? We do have the float setting parallel to the carb seam - where the halves separate as a reference.

[romantic comedy]

why did you rebuild the carb?
Was the engine running before?
You say that the throttle will not change RPM?
What RPM is it at?
Is the choke closed or open?
How is the compression?

[sandiegomike]

Whippet - thanks, I will order the video for $12.50.

[sandiegomike]

Romantic, thanks for the reply. The engine was running fine in November 2015. I went to start it in March and there was no raw water exhaust, so we did an unclog on the exhaust manifold and then a compression check. We found the exhaust valve stuck open on number 3. We removed the head and unstuck the valve. Replaced the head gasket, exhaust gasket, exhaust manifold gasket. We got the engine running, but not strong...not sure of the RPM but I walk faster. Compression from what I recall is 90-100psi. Choke is working fine. We rebuilt the carb because everything else seemed to be running good - good compression, good fuel, good fuel flow, good spark (tested with a spark tester) , good exhaust water, good spark at points, good timing - just a lot of spitting of fuel up through the spark arrester and seems like excess fuel on the plugs.

[JOHN COOKSON]

John Cookson "Edit: I presume the float drop is set correctly?"
I am not sure what this means. Can you explain a bit. I have not seen float drop anywhere? We do have the float setting parallel to the carb seam - where the halves separate as a reference.

I have it in a PDF file. Lower right.

TRUE GRIT

[sandiegomike]

Issues continue

Hi all, issues continue, but now I think I have the "too much fuel" issue taken care of by adjusting the float drop, but now won't start. I will readjust in the next couple days. I am learning a lot about carburetors based on your help and a good friend of mine. We will also perform another compression test.

John Cookson, where did you get your fuel pressure gauge?

[roadnsky]

...where did you get your fuel pressure gauge?

Quite a few of us use this one...

https://www.amazon.com/Mr-Gasket-1561-Pressure-Gauge/dp/B000BWCFLO/ref=sr_1_3?s=automotive&ie=UTF8&qid=1466950411&sr=1-3&keywords=fuel+pressure+gauge+kit

[JOHN COOKSON]

Since the engine won't start, before pursing the fuel side further, be sure you are getting spark.Here's a simple test. Pull a boot off a spark plug, put a screw driver in it and hold it near the spark plug and see if you can jump an arc to the spark plug while cranking the engine.
I didn't reread the thread: Are you keeping the cooling raw water valve closed when you are cranking the no start engine?

TRUE GRIT

[sandiegomike]

Fuel pressure gauge

Guys,
Thanks for the link to the fuel pressure gauge.
John, yes the raw water is closed during cranking. I will try the arc jumping test, but think I am good. I have a spark tester I have used to confirm spark.

[sandiegomike]

Now no compression

Ok, now we have no compression on 2,3 and 4. The large valve moves on 2 and 3 and on 4 the large valve is not moving. When we originally removed the head 5 weeks ago only the small valve on 3 was stuck, which we thought we cleaned well enough and reinstalled. Number 1 has 95 psi compression. Which all of them had when we reassembled everything 4-5 weeks ago.

Question: Is there something we can do to polish the valve stems and valve guides so they don't stick?

Is this considered carbon build-up?

Is there a round brush or polishing device to use on the valve guide?

The head gaskets are new from 5 weeks ago and also the valve cover plate. Do I need to purchase new gaskets again?

Wisdom and guidance appreciated!