'68 F-head stalled

Just like it says - I had it running for about 15 minutes warming up in the driveway (-16 degrees celcius), hopped in and got to the end of the driveway. The motor just stopped - had good oil pressure, engine turned over very well, but no putt-putt or anything - checked for fuel - had about 1/4 tank - added 1.5 gallons. still no-start - used the starter to
get it back into the garage, and let it sit. Charged the battery and came back to it 3 days later - started right up!
Took it for a little cruise around the block - noticed a definate sputter that wasn't there before, and a distinct lack of power at around 2500 + rpm - enough that I put it back in the garage for tonite -

sorry - a little mechanical background - F-head 134, Pertronix conversion, Carter YS carb (Military style), original coil, new wires, cap, rotor and plugs less than 100 miles ago. Was running like a champ a week prior to this.

any ideas?? am I overlooking something obvious? any suggestions are appreciated -

Thanks
Chris

 

When's the last time the carb was rebuilt?

 

SOunds like it may be running rich or you fouled a plug or two while idling in that balmy weather. Check/replace your plugs, make sure choke is open when cable is all the way in. My plow rig did the same thing two years ago when it was idling for a while. New plugs and away we went. ymmv ALso, check your fuel filter.

 

Carb was rebuilt 4 months ago -I put a new float in it too -it's kinda strange -I had no problems when I drove it a week before -

Fuel filter is a good thought........plugs are cheap too....
might as well start there -
Thanks.

 

if the tank is low with gas, and its real cold, it could condensate, causing water to sink to the bottom. try some "fuel dryer" i forget the name.

 

back in yhe early 1980s i had a cj 3b with the f head 4.it dropped down to all most o degrees f.mine did the same as yours.found out the oil bath air filter had got water in it from condensation and was blocking my air flow.disconnected the hose and it ran fine.when it warmed up the ice inside it melted and hooked the air hose back to the carb and it ran fine.i did not drive it every day and evidently the water built up over time and when the temp dropped low enough it froze and blocked the air flow.

 

Hmmm. well, I have removed the oil bath air cleaner and am running a K&N cone style filter on the intake tube. Picked up a rebuilt YS carb on Sunday, gonna swap it on with a new fuel filter, throw a new set of plugs (NGK), cap, rotor, and wire set (MSD 8.8 ). Then I figure I'll finally get around to installing the MSD Digital 6 ignition box and coil I have lying there..... Damn thing better run after this.........

 

Uhh you could have just rebuilt your carb...sounds like what they said or also a piece of crud in the carb.

 

With Christmas and a new baby, lack of garage time is an issue -
I plan to swap the carb, then rebuild the old one this spring/summer, as time allows - right now, I just want the Jeep on (and off) the road -
it was sitting disassembled for 3 years and now I just want to drive it.
If any future modifications are in the works, I want there to be a minimum of down time because I really like driving it around here.

 

When I was in high school, I had a '71 VW Super Beetle, and carb ice was a MAJOR issue with that thing. The intake manifold is a skinny pipe that sits above the engine, and it took forever to heat up. The winters in Butte Montana are pretty brutal, and that thing was the biggest PITA to drive. Just getting it to run was bad enough, but even when it did the "heater" felt like a dying rat coughing on you.

If you plan on running it much at temps that cold, you might want to put some sort of engine heater on it...the faster that head gets warm, the faster the carb warms up. You might even try just using one of those magnetic heaters, and stick it on the cylinder head.

 

I agree with the carb freezing. My CJ7 years ago couldn't stand that temperature without the heat riser working, and the duct in place.

Paul

 

X2 on the VW iceing even in tennessee I finally mounted a sealed beam headlight shining on the base of the carb. with a switch on the dash to heat the carb. kind of a "dutch" heater but it solved the problem.

 

Well, I swapped the carb with a rebuilt unit, put in a new fuel filter, and swapped the plugs - started the Jeep and it will not run unless the choke is at 3/4 or so - sputters and chokes, no power - will not idle... that was at 2 am today, so I just gave up for now. There was no fuel in the fuel line or the old filter when I removed it, leading me to believe the fuel pump may be the cause......maybe running really lean because the pump cannot keep up?

 

Sounds about right to me...check out the fuel pump