As the story goes. Rebuilt carb 27.5mm W/new jets and needle (from bing), set air and idle, starts first/second kick idles fine. Runs down the street well, and has been working just fine for the past 2 months.
Today on the maiden voyage to the trails wouldn't kick start acted like it was flooded (bump started) rode down the dirt road and back to truck (stalled) wont restart (bumped again) rode fine, again no idle. Re-set air and idle screw and is now stuck on a high idle and will not come down no matter where the idle screw is set. While running engine is strong through all the gears. Checked air/gas and spark.
Before I tear blindly into the carb for the millionth time, I would solicit suggestions. Thanks
Scott
Jacksonville, Florida
72 Six Day
Jax, FL
Scott,
When you open and close the throttle, can you hear the slide hitting the bottom of the carb? If not, make sure the slide is not stuck and if it is not, adjust the cable till you can hear the slide coming in contact with the bottom of the carb when you release it.
Kevin.
Kevin J. Donovan
Foster, Rhode Island
72 Jack Piner (My Ride)
72 Six Day (Wifes Ride)
73 Yamaha AT3
71 Suzuki TS125 (Project)
Air leak??? Crank seal???
Thanks Kevin, I was thinking that the slide was the possible culprit, although it is amazing that it was great for so long and it just sticks all of a sudden. I'll check it out and see. Thanks for the quick response.
Scott
72 Six Day
Jax, FL
I have found out the hard way the ethanol in the fuel will clog pilot jets if bike allowed to sit for a while. Sounds to me that this might be what is going on with your bike. Fix is to clean it out and start using a ethanol treatment in your fuel. Don't need but a bit but sure protects those jets. Good luck.
Thanks socalmx, Just finished a good carb clean including cleaning the jets and polishing the slide also changed the plug with no change in the result. Also disconnected the kill switch, just because. I'm wanting to think that it might be fuel starved with a sticking needle valve/float. Has anyone experienced this?
Scott
72 Six Day
Jax, FL
I hope you are not running Gasohol (E10) in this bike. Ethanol will eat the fiberglas tank and you can get rosin and trash into your carb and petcocks. Run lower octane race gas or non ethanol gas or a least AvGas (not the best choice but better than E10).
Had same symptoms at least 2-3 times. Plugged pilot jet. New ones work best but careful cleaning with fine wire or welding tip cleaning tool works. I'd start there.
Dwight/Mac,
I've been running normal pump gas (93 octane) and draining the tank after use/re-build sessions. I do have two non ethanol options in my area, one being 89 octane and the other 100 octane. What are you guys running (ethanol/non ethanol)?? I have been using the same mix in my 03 yz125 with no issues so far. I'll re-check the pilot jet this weekend, it appears to be clean but I did not pass anything through to push out any unseen debris. I'll do that this week.
Thanks again with all the suggestions, for the brief moments that it was running yesterday it ran like a scalded dog. To say that I was amazed is an understatement and i'm excited to get this bike out.
Scott
72 Six Day
Jax, FL
Still working on the same issue on 125 Six Day and looking for new suggestions. Currently bike will start and run as long as I have the choke on but will not idle or run with the choke lever disengaged. New parts as follows,
Bing 27mm carb
Jets (all) 35/140/2.73
needle (set at 2nd position)
slide
float needle and seat
All the jets are clean and free from obstruction, float needle works as it should with fuel going to the carb and enricher working properly. Float is not cracked or leaking. I may clean out and reseal bottom of choke plunger next since I am running out of things to try short of a new carb which should not be needed.
The frustration lies in the bike was running well and all of a sudden developed this problem. Ant suggestions.
72 Six Day
Jax, FL
Pilot pass way plugged.
I've encountered a similar fault with my Jackpiner. Scrapping the Amal I went to a 30mm Bing. Had it running well with a slide that was not cut for the choke. Didn't start the best and had to dribble some gas in the plug hole but once warm it was fine with no choke cable connected. Installed a different slide which looked a little more worn with the cutout and choke assembly installed and it will only now run with the choke on. It could have been the cold day and it will be a while before I can get back out outdoors. I suspect in my case the slide is the first thing to investigate further.
Dale Fisher
POG Memberships
74 Berkshire 100
70 Six-Days 125
73 Jackpiner 175
Buy a 26/28mm Mikuni and forget about it.
Brian
Gary/Dale/Brian,
Thanks for the quick replies. I've blown out the pilot jet and pass with the compressor, i'll see if I can't pull it apart again today to further clean the pilot pass.
I'm not going to give up on this carb just yet although I have been looking at and reading all the old posts on Mikuni vs Bing and as well as I can tell most members feel the Bing produces slightly more bottom power.
I also have been using basic 93 octane unleaded in the bike with a 40-1 mix. I do have a station locally that sells 89 grade with no ethanol.
72 Six Day
Jax, FL
People say the Bing makes more power, but you will never feel the difference IMO. If anything the Mikuni will have better low/mid response and a bit less top end. 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. You can mount a 26mm Mikuni without doing any kind of irreversible mods to your bike, so if you ever want to go back to 100% original its as simple as putting the Bing back on. If you want to actually RIDE your bike, do yourself a favor and buy a Mikuni, you wont regret it.
Brian
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
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. :D
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.
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
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
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
Quotequote: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
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[:p] Bing is still the best in my eyes, have never had a problem with them for 40 years and are very easy to rebuild.:D
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
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