Mikuni carb

[john durrill]

Mickey,
The type 53 stock Bing that came on the Penton would work well.
Its only .5 mm smaller than the 28 mm type 84 and fits. The max size you can go on the standard cylinder would be 28 mm because the intake spigot can only be opened up to 28 with out becoming weakened. Thinning out the spigot to take larger than 28 mm is not a good idea.
 Do you have the stock carb that came on your bike in hand?
New slides are about $20 from one of out parts suppliers.
http://cgi.ebay.com/ebaymotors/BING-NOS-Carb-Slide-Penton-Sachs-Hercules-Tempo-DKW_W0QQitemZ110376231433QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item19b2efa209
 You can get a New 26 mm body from the same supplier ( call Tom at 608-295-3839 )  if yours is damaged beyond repair , use the parts from your carb with a new needle jet and float needle to fix what you have. Forest or JP should be able to ream out the 26 to 27.5 if you ride it and think the 26 is too small.
hope this helps ,
john d.
 

[Gary Roach]

quote:Originally posted by Mickey Sergeant

I just finished a 74 berkshire.I'm having the same problem your experiancing.Replaced needle and jets that someone recomended to me.Helped a little.Wont Idle wants to die.Checked plug shows signs of being rich.One thing I noticed was when checking float level was that float tab would push float needle down.Am I wrong or should floats be resting on float needle without pushing it down?If this is the case could this be my problem?All feedback needed.

When you had the carb apart, do you happen to notice if the rubber seal on the bottom of the choke plunger is either deteriorated or missing?

[joe novak]

Thank you to all those who added interesting information on Sachs carburation; both Bing and Mikuni.  But what about that other carb; Keihin?  How well do they work?  I would like to add that my Bing 53 ran great on my Penton 100, but the Bing 84 (28 mm) ran better.  I also prefer the Bing 84 (28mm) because it has a brass fitting for fuel overflow, like the tickler, which dumps the fuel into a plastic fuel line.   The Bing 53 has an open slot on the side of the carb which the fuel dumps onto the side of the carb.  I do not like any openings which may allow dirt or debris to enter the carb.   Joe

[rob w]

Remember when a 30mm Amal was the hot set up on a Six-Day ?

[Mickey Sergeant]

I have taken all the info in from everyone.Purchased a new 26mm mikuni.Should work well for what I need. Will be here in a few days.Bike is all stock,no modifications.Called bing they have a exact replacement.Well over $300.To much out of the budget for me.Still Need to purchase progressive shocks. Will check out hoses at napa for mounting.Again thanks for all the help,Didn't think that mounting a new carb could be so complicated.

Mickey Sergeant
74 Berkshire

[Mickey Sergeant]

Joe,Thats the first thing I learned.It was missing.Filled up With good silicone level.Made a small improvement.Started a little easier,Still would't idle at all.Decided to just purchase new carb,Rather than keep messing with the old carb. Want to be at the races this month.

[brian kirby]

Just my opinion, but progressive shocks are not worth it. They work very well, I actually prefer the performance of Progressives to Works or Ohlins, but the Progressives are not durable enough. They are 2/3 the cost of Works and not nearly as durable. IF Progressives would not blow seals I would use them, but I think you are throwing money away on them unless you are just going to do mild trail riding.

Brian

'72 Berkshire

[Lloyd Boland]

Brian, I would agree with you, the Progressives work well but I have also blown seals on them.  The last time was about a year ago, one side blew out on a drop off at Glen Helen, caused a huge tank slap and oil everywhere.  I dented the top of a new metal coffin tank on my CZ I just got from CR Products.  (Yes that is right, I dented the top of the steel tank at the top crease when I came down on it.) I now talk 2 octaves higher.  They work well but the seal thing is an issue.

Lloyd

[socalmx]

I strongly suggest going with the Mikuni vs. a Bing. For mounting it, I used clear hose that I purchased at Home Depot (for way less than auto filler spout hose). It worked well in the day and still does today. It gets hard after about a year so you have to change it out from time to time but no problems with deterioration. Regarding the fuel line, I used a very short piece of fuel line from the carb to a hand formed hard line (used brake line) to go under the pipe and upward on the right side of the bike. The fuel tank spigots are connected to it with fuel lines and a "T" fitting. This eliminates the risk of burning the fuel line on the pipe, etc.