Gas in oil again

You need to add a $4 lawn mower shut off valve.  Unless you sit in car with key on listening to radio it sounds like carb float valves are sticking open.  Carbs will need to cleaned.  I'm always quick to point to gunk build up in ethanol gas as cause.  Did you have ethanol gas?  Was it treated with stabilizer for ethanol gas?  Good thing you don't have an ignition source (gas hot water heater) in garage.  

Wolfgang

I use standard 87 octane gas.  I did put some staybill in tank before storing it. 

Do you know if your electric pump has a check valve in it? Sounds like your siphoning fuel.

Mike

I don't know if it has a check value.   I will have to take a closers look at it.  The pump is up front behind the fuel tank.  I can see it through the wheel wells.  I think I need to take the carbs out clean them and adjust the floats.

The fuel level in the tank is higher than the float-bowls, most likely. If those dual 34s are Kadrons, they have notoriously bad needle-and-seat valves (float valves). If they aren't, my money is still on the float valves. A check-valve wouldn't help it if it were siphoning (but it's not).

Good luck. 

I agree with Stan. I had a similar issue last winter with my Speedster. I had it parked with the front end slightly higher than the rear in my driveway and gas was pooled on the ground. I ended up rebuilding the top end of my Webers. I believe a float bowl needle valve got stuck open or did not seat right in the 3/4 carb and gravity did the rest. I had lots of fuel in my oil. After the new needle install I flushed the oil 3-4 times. I now I try never park it with the gas tank higher than the motor.  

I like the idea of a shutoff valve on the fuel line below the tank for storage but maybe a brass one rather than plastic.

Stan

The carbs are 34 weber.  I agree that the problems is with the carbs. I will take them off this week and take closers look.

Thanks guys

put a switch on the fuel pump, so you can run all the gas out of the carbs. bill

buckwheat posted:

put a switch on the fuel pump, so you can run all the gas out of the carbs. bill

 

That won't keep them from refilling if the fuel level is higher than the floats.

It's not ethanol, It's not the fuel pump (although a non-siphoning pump would be nice, but probably a lot louder - they're usually solenoid pumps) and you don't need a check valve or an extra fuel shut-off, although Al Gallo installed a Marine fuel shut-off under his tank to make it easier to change the fuel filter.

I totally agree with the Pilot Valve camp - The problem is probably a carb pilot/float valve stuck open, or it may be a leaking accelerator pump gasket or pump check valve that drains the bowl.  Either way, the fuel gets out of the carbs and drains down into the cylinders and then, well.....You've seen the result.

Get a pair of rebuild kits for your carbs from CB Performance

 http://www.cbperformance.com/R...ccessories-s/167.htm

Most, if not all, of these kits come with new pilot valves so replace old with new and that should cure the pilot valve problem.  It takes another five minutes each to replace the accelerator pump stuff while doing the rebuild, so go further than just rebuilding the top end of the carbs and do the whole Monty - What the heck.....You've got them out anyway and there'll never be an easier time to do it.  Make sure you blast out the passages, especially the accelerator pump ports and passages with a good carb cleaner, like Gumout, and the check ball, too.

Make sure you re-set the float level after replacing the pilot valves - no new batch of valves/seats is ever precisely the same as your wicked old ones in there now.

I agree it's the float check valves BUT they just don't go bad that quickly.  Something is causing them to stick.  Regular 87 octane gas is 10-15% ethanol in US.  Ethanol absorbs 50% more water than non-ethanol gas.  It has advertised shelf life of 90 days but in a vented system like on VW gas tanks it can go bad within 30 days (since the vent lets in even more moisture). Further, it eats rubber/plastics/alumium, gas tank linings, rust/varnish/dirt in fuel system - that gunk then flows thru lines and clogs jets and float valves.  Good justification for a filter under gas tank and second one over transaxle.  Regular Sta-Bil is not enough - you need one specifically for ethanol gas.  Stabil 360, Lucas and SeaFoam make them.  If you have small garden gas motor or marine outboards ethanol is a real killer - all engine manf say run engine dry of gas before putting it up for the winter. Fortunately, non-ethanol is obtainable around FL coast - at maybe 50 cents more per gallon - even 91 octane.

Gasoline (non-ethanol) has 117600 BTU per gallon, ethanol 67000 BTU per gallon (diesel fuel produces 128,450 BTU per gallon). Ethanol creates 34 percent less energy - so E10 means 10% less MPG! That's 3 miles per gallon less.

Good article aimed at antique British cars-

http://www.mossmotors.com/Site...s/Pages/ethanol.html

SEMA has also made ethanol in gasoline one of its legislative priorities, opposing the pending rollout of E15 fuel. For more information on that effort, visit SEMASAN.com.

https://blog.hemmings.com/inde...s-on-collector-cars/