Six Day bing issue

[taxman]

I had this same prob---years ago on my 72 6 day---check the crank seals. Its odd that it ran and stopped. Just my opinion---take it what its worth.

Jim

[Big Mac]

If it suddenly changed after running good, seems it could only be a change due to carb clog or air leak. Running better on choke sounds like lean due to same. With carb checked and clean, and able to hold up the pilot and see light through it, very well may have had an ignition seal go out or leak develop in intake tract or base gasket?

If you can get it running roughly with choke on, you can spray WD40 or carb cleaner through the spray straw around the carb front/intake manifold, at base of cylinder and in around behind flywheel with mag cover off. If it's sucking air, you should hear the revs rise noticeable as it burns the spray. Best way I know to find an air leak.

This is a Bing with the plunger type choke (mini-slide within the slide) operated by cable to handle on the bars? A friend many years ago--no names here--with the same Bing pulled his hair out due to blubbering/smoking and only getting his Penton to run with the choke "on". We pulled the slide and air filter searching for the new problem...only to discover he'd forgotten that choke "on" is cable loosened, handle opened, and choke "off" is cable stretched, handle bound down. Worked fine when he regained his mental aptitude on the subject. Hope you've got THIS checklist item cleared.

[Paul Danik]

Brian,

    Having put a few miles on a couple of Bing equipped Pentons in my day, and having never "worn out" my carb, I question your statement below.

Thanks,
Paul

The one big difference is with a Mikuni your bike will run the same way every time you start it and it wont wear out in a few months of use.

[Scott Summey]

Mac,

Gave it a shot with the WD40, pulled the re-cleaned the carb jets, reset the bowl re-sealed the choke plunger, and took a video which i'll work on posting the link for you guys to view.

Here's where we're at now.

Starts right up with the choke on settles into idle again with the choke on, release the choke and it acts fuel starved, revs momentarily and then dies. Pull the choke back on before it dies and it settles back into idle (choke on). Let it die pull in the choke and give it a kick no throttle and it starts right up settles into fair idle.

Again these are new Jets, needle, Slide, float needle and seat. So pretty much most everything that you can replace short of a new carb.

72 Six Day
Jax, FL

[454MRW]

Do you have a handlebar mounted choke lever? You mention that you "pull the choke back on before it dies and it settles back into idle". If it has a handlebar lever, pulling the cable tight turns the choke off and letting the cable slack, lets the choke slide down into the carb throat, turning the choke on. It sounds like you have the idle under control. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[Paul Danik]

Scott,

   Are you sure that the flow from the tank to the carb is totally unrestricted? Have you inspected the wire mesh filter inside the tank on the upper part of the petcock? When the engine is running try tickling the carb and see if that makes any change in how it responds, what I am looking at is eliminating the idea that there is fuel starvation to the carb.

Hope this helps.
Paul

[OUCWBOY]

quote:Originally posted by Paul Danik

Brian,

    Having put a few miles on a couple of Bing equipped Pentons in my day, and having never "worn out" my carb, I question your statement below.

Thanks,
Paul

The one big difference is with a Mikuni your bike will run the same way every time you start it and it wont wear out in a few months of use.

I'm with you on this Paul. NEVER had any problems with Bing carbs. I did replace the carb on my 1972 Jackpiner which came with an Amal.

Donny Smith
Paragould, AR

[Kip Kern]

Does the bike have the old style choke mounted on the side of the carb body and is controlled by a trigger type choke lever?  If so, check the seat of the choke as most fell apart and stopped functioning properly.  Check ignition/coil grounding too so as to be safe.  Had to chime in[]  Bing is still the best in my eyes, have never had a problem with them for 40 years and are very easy to rebuild.

[Scott Summey]

Paul, Good flow from the tank to the carb. Reset float bowl and checked to see if fuel had good flow with bowl off which it did (opened and closed correctly) tickling while running did not change how it responded. bowl is getting fuel.

Mike/Kip,

Carb is 27mm with lever on the handlebar that operates the choke by cable. reset to have no slack in the cable so that when pulled to the bar it raises plunger in carb. Seat was re-sealed with high temp fuel resistant silicone (learned that on the forums). Slide is traveling down to the bottom of carb but idle adjustment does not affect idle with choke off.

I did lower needle to 3rd and 2nd position which at this point keeps me running with throttle 1/4 -1/3 open but will not idle (bogs down and stalls out). Screwing the idle screw in does nothing till just about all the way in then just pegs the engine as if the throttle we're wide open. Air screw has been adjusted in the range of 1 1/2 to 2 1/2.

So for the day I'm done I've hit my frustration level. The best part of this whole process has been all of your suggestions and interaction. This is exactly why I joined POG. Thanks

Scott
Jacksonville, Florida

72 Six Day
Jax, FL

[Steve Minor]

Sure everything was reassenbled properly? I had a carb problem once that turned out to be my fault totally. I had installed the needle and clip inside the plastic retainer cup rather than under the cup. Thought I'd never get it straight...turned out to be my carelessness....
Just a thought.

Steve Minor
Wilmington, NC