jackpiner mikuni switch

[Denis Jeffries]

I would like to trade out the bing on my jackpiner to a 34mm mukini. Would this be to large and what type of problems will I run into.
 Thanks for the help
 DJ

[Dwight Rudder]

The bike came with a 30mm.  I wouldn't go bigger than a 32mm. Many people go with too big a carb and gain top end at the expense of low end.  I suggest keeping your low end torque.
IMO,
Dwight

[Denis Jeffries]

Dwight,

 Thanks for the help. I'll try and find a 30mm or a 32mm. Thanks again
 DJ

[brian kirby]

Dwight is correct, typically you only need to go up 2mm when doing a Mikuni swap and as he said it had a 30mm Bing stock so 32mm is the size you want.

Brian

'73 Berkshire

[VICTOR MONZ]

DJ.

I'll take that "old" Bing off your hands, once you've went Japanese.

E-mail me offline if you want me to dispose of it for you.

Victor

[Denis Jeffries]

quote:Originally posted by brian kirby

Dwight is correct, typically you only need to go up 2mm when doing a Mikuni swap and as he said it had a 30mm Bing stock so 32mm is the size you want.

Brian

'73 Berkshire

[Denis Jeffries]

Brian,

 Thanks for the info. I've found a 30mm and a 32mm.

 DJ

[clayman]

I am having carburetor issues with my 1973 175 Jackpiner. After a thorough cleaning it runs momentarily but then runs out of gas. This is a goofy question: is the handlebar-mounted Magura lever intended to be a choke? It ran great with it in the "open" position but barely runs with it off. Are rebuild kits available for the Bing (Model 84)?

Or, should I avoid all of the headaches and put a 32mm Mikuni on it? If so, I won't be able to mount the carb to the airbox boot, will I? Does anyone have the jetting specs for the Mikuni or an idea if I can get one already set up?

Thanks so much,

Clay

[G Ellis]

Clay the lever on the handle bar is a choke. On position is when the cable has nothing showing. Off position is when the cable slack is taken up. When riding I like to take a piece of tube and tie it to the crossbar in a loop. Hooking it to the choke so it does not slide open. Hope this will help. Gary

[Steve Minor]

Gary is right about the inner tube trick...it works great. Here's another trick....If you come up on a long, high speed section like pavement, apply the choke slowly (while riding) util the motor starts to sputter, then back if off slightly. You may have to fiddle with it some. This will help prevent the piston from seizing. Just remember to reset the lever when you get back into the tight stuff...

Steve Minor
Wilmington, NC

[tomale]

clay, Are you sure that the problem is not petcock? Or maybe the float is sticking closed. but I am also wondering about the condition of carb, when is the last time that the slide or the needle jet/jet needle been replaced. A conversation with Bing Int. recomended to me that the needle jet and jet needle needs to be replaced once a year. and if the slide is worn it needs to be replaced as well...

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)
72'sixday (project bike)

[clayman]

Hi Thom,

I loaded the JP 175 in the Toyota and made a road trip yesterday, meeting Larry Good in Roseburg where he pulled the carb and noticed that the float level was off and a couple other issues, so thanks to LG for diagnosing the Penton. He also hooked up me and our buddy John Raliegh with a lot of good parts....Thanks LG!:)

Hope you are doing well Thom and I'll see you at the next Woodland....please don't forget the sidepanel, I sure need it for the 125 Six-Day project. Have a good weekend.

Clay

[tomale]

glad to hear that you go it worked out... I sent you a note about the sidecover..

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)74'
250 hare scrambler (project bike)
72'sixday (project bike)

[clayman]

Thom,

It looks like I'm back to where I started, though, on the 175.

It fired right up and sat there and idled for 6, maybe 7 minutes and when I went to ride it, I got about 5 feet and it sputtered to a stop and wouldn't start again. I changed the plug several times and gave it a shot of starting fluid, but it's a no-go. Well, maybe LG knows what it is.

Got your email, thanks....see you at Woodland.

Have a great week!

Clay

[gooddirt]

Did you take the bath towel out of the air box?[:0] And take off the SuperTrap end cap and start it ! It needs at least 2 to 3inchs of dics not the 1/4 inch you have:(. The spark I think looked a little weak  but it was raining pretty hard and my glasses fogged .[8D]