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KSIS
11-18-2009, 01:16 PM
I have a set of rebuilt HU's on my 1300 Spit. They run good but everyone in a while the floats will stick and fuel will pour from the wep holes.
A little tap with the screw driver and she is good to go. What do I need to adjust or check to stop this from happening. I am afraid they will stick one day and I wont catch it till its too late.

TR3driver
11-18-2009, 01:57 PM
The most common cause of that is crud in the fuel, perhaps from a hose somewhere that is deteriorating inside and shedding bits into the fuel. The bits get caught in the valve and keep it from closing all the way.

Replacing all the soft lines on my TR3A made the problem disappear.

tomgt6
11-18-2009, 02:04 PM
I had some of that issue and it was because the float was bent up a bit, to much play and then later it was because it had a small leak. I like tr3driver suggestion as well. It could also be a small burr on the needle that is catching.

KSIS
11-18-2009, 02:37 PM
The carbs were professionally rebuilt by a MK2 racer. I will look into replacing fuel line and move the filter ahead of it all. Thanks for the advice.

poolboy
11-18-2009, 04:09 PM
As long as you are replacing the fuel lines, you may want to consider using the bit more expensive "fuel injection lines".
The fuel injection line at NAPA specifies that it's alcohol resistant, whereas the regular fuel line from the same source made no such claim.
I remember our first bout with gasahol back in the 70's contributed to a lot of fuel line deterioation.

KSIS
11-24-2009, 12:51 PM
So I replaced the fuel lines, put an in line filter right before the fuel pump, cleaned out the bowls with carb cleaner and started it up. Was good for a few days but the rear bowl started over flowing on the way to work today. I gave it a few taps and no luck loosening it. I took my chances and drove the rest of the way.
Any other suggestions?

tomgt6
11-24-2009, 01:03 PM
I was having issues with the back bowl overflowing and found that my fuel pump was putting out 7-9 psi and it should be 1-3 psi. Changed out the pump with a new one and that fixed my issue. But I also cleaned all the edges of the float needle to make sure they didn't have any small burrs on them.

But check your fuel line pressure.

ekamm
11-24-2009, 04:53 PM
Make sure that the float isn't leaking. Remove and shake it to see if there's any gas in it. I just replaced one of mine.

DrEntropy
11-24-2009, 05:11 PM
A whack with a "blunt instrument" wouldn't fix a leaking float as described earlier but since that didn't work this time it wouldn't be outside the realm of possibility.

This sounds like a case of either the pump pressure bein' too high or effects of junk or ethanol schmaze on the needle/bore. First step in either case is to pull the things down and inspect and clean the float needle valves... And if you find Gross(e) jets in there, I'd be sayin': "Ah-HAH!!"

Pay attention to the aforementioned problems with ethanol "enhanced" fuel. The stuff will cause all manner of buggery. From decomposing fuel lines to causing a build-up of deposits at the jet and float needles. Not much short of disassembly and THOROUGH cleaning of components mechanically will remove it. #000 steel wool and conscientous cleaning of any errant 'swarf' is about the only way.

dklawson
11-24-2009, 10:33 PM
Dr. I'm not questioning your personal experiences with ethanol rich fuels, but I do wish to mention that recent studies at Kettering University (sponsored by Hagerty and reported in their quarterly newsletter) found that the effect of ethanol on fuel systems is slow and not too severe. Their tests did include SU fuel system parts. However, I doubt their tests included well aged, old formulation rubber parts as may be found on many of our cars.

TR3driver
11-24-2009, 11:03 PM
Studies like that can be tricky things. Perhaps the problem is not just ethanol, but the interaction between ethanol and other chemicals in the fuel (which may vary between various parts of the country and even different seasons in the same area). Or possibly it has nothing to do with the ethanol, and the culprit is some other chemical they are adding at the same time.

And while I would agree with the "not too severe" label (other than dissolving fuel pump diaphragms); I have seen a distinct increase in the number of problems with "stuck" floats & clogged jets since CA switched from MTBE to ethanol a little over 5 years ago. When my lawnmower was "put away wet", I literally had to disassemble the carb and chip the deposits out to get it to run again.

Got_All_4
11-24-2009, 11:23 PM
I wouldn't be afraid of gross jets if they are installed. They fixed my problem in my TR3 when I was only getting 1 year out of the float jets replacements and this happened twice. The rear carb was the problem the 2nd time and discovered that there is a problem with the red rubber tipped jets which that carb had. Seems they don't hold up to the fuel blends. The front one has a black tipped jet and has been in there for 2 years + now and they are much better with the fuel blends but are not available any more.

I replaced the rear float with a Gross Jet to the dismay of 50% of who responded to my question whether to install them. I took the advice of one of the posters that told me to soak the Gross Jets in carb cleaner and blow it out with air. When i did that there was lots of fine brass filings in the bottom of the cup they were soaked in. It's been over a year now and no problems. If you directly install the Gross jets out of the bag without cleaning them the brass filings you'll have problems because the filings stick to the coasmaline there shipped in and that causes the floats to leak. I have a cleaned spare in the glove box for when that front one goes bad. Don't forget to properly set the gap for the float. That's critical!

dklawson
11-25-2009, 08:17 AM
gross jets... I have a cleaned spare in the glove box for when that front one goes bad.

I'm sure I was one of the naysayers speaking against Gross Jets. I'm glad you have had luck with yours. I did not, not with either set I tried on two cars. You say you've washed out the Cosmoline and have a "cleaned" one in the glove box ready for use. If you haven't already done this, I hope you'll take the time to dip the jet in something like gear oil and then place it inside a Zip-Lock bag or two. That Cosmoline you washed away was probably there to prevent the Gross Jet ball from corroding in storage. When not in use and without the Cosmoline, it's just a matter of time before the ball will start developing rust.