Penton Owners Group

General Discussion => Penton Talk => Topic started by: KJDonovan on January 02, 2012, 04:29:37 PM

Title: Connecting Mikuni Spigot to 125 Head
Post by: KJDonovan on January 02, 2012, 04:29:37 PM
I am setting up a 74 Six Day and it came with a 28MM Mikuni VM spigot that the owner would like to use and I am looking for some kind of rubber boot to connect the 35MM OD spigot on the carb to the 40MM OD spigot on the head.  Can't seem to find anything online or at plumbing supply stores.  Anyone been down this road before and have a solution they can recommend?

Thanks,
Kevin


Kevin J. Donovan
Foster, Rhode Island
72 Jack Piner (My Ride)
72 Six Day (Wifes Ride)
73 Yamaha AT3
71 Suzuki TS125 (Project)
Title: Connecting Mikuni Spigot to 125 Head
Post by: DKWRACER on January 02, 2012, 05:14:49 PM
Kevin, this may work. I think when I had my mod done, my machinist milled down the circumference of the engine manifold, then we went to a local vendor and found a section of rad hose that was a close fit for the two ID's, adios....Tom Brosius
Title: Connecting Mikuni Spigot to 125 Head
Post by: KJDonovan on January 02, 2012, 05:29:07 PM
Tom,

Thanks for the tip, I was hoping to avoid milling down the OD of the spigot on the head in case they ever want to switch back to a Bing, but you did give me an idea.  Tomorrow, I'll head to NAPA and see what they have for radiator hoses that are slightly smaller than the OD of the intake and slightly larger than the OD of the spigot on the carb. With all the small cars these days, maybe I will find something that will work.  I'll let you know what I find.

Thanks,

Kevin

Kevin J. Donovan
Foster, Rhode Island
72 Jack Piner (My Ride)
72 Six Day (Wifes Ride)
73 Yamaha AT3
71 Suzuki TS125 (Project)
Title: Connecting Mikuni Spigot to 125 Head
Post by: Dwight Rudder on January 03, 2012, 03:34:02 AM
Usually with a "B" cylinder you will need to increase the size of the cylinder spingot with a press on sleeve so you can install a 28mm Mikuni VM.
Title: Connecting Mikuni Spigot to 125 Head
Post by: socalmx on January 04, 2012, 05:38:55 PM
I mated a 30mm Mikuni spigot mount carb to a GS 125 cylinder. I used clear tubing from Home Depot that had the correct inner diameter and a couple of hose clamps. This type of tubing was used commonly in the 70's and has not been caused me any problems. When it starts getting yellowed and/or brittle, it's cheap and easy to replace.
Title: Connecting Mikuni Spigot to 125 Head
Post by: KJDonovan on January 06, 2012, 04:56:58 PM
Thanks for all the idea's, here's what I ended up doing.  I couldn't locate a piece of radiator hose that was in between the 35MM spigot in the carb and 40MM spigot on the jug.  So I got a 1-1/4" rubber pipe coupling, which has an ID of 1-1/2" and a short piece of 1-1/4"ID tygon hose.  Cut ¾" of the tygon hose warmed it up a little on top of a lamp and slid it over the spigot on the carb, kind of a bushing to make up the difference between the OD of the carb spigot and the ID of the hose coupling.  The rubber pipe coupling fit perfect over the spigot on the jug, but was a little tight over the tygon bushing on the carb, so after cutting it to length, I warmed it up on the lamp and slid it right on.  Everything looks good and more importantly fits tight, so I won't be sucking air.  Thanks again for the tips!

Kevin

 


Kevin J. Donovan
Foster, Rhode Island
72 Jack Piner (My Ride)
72 Six Day (Wifes Ride)
73 Yamaha AT3
71 Suzuki TS125 (Project)
Title: Connecting Mikuni Spigot to 125 Head
Post by: gooddirt on January 06, 2012, 06:36:35 PM
You could remove the 40mm bushing; as its just glued on the smaller spigot. A run of the early 74's have the B barrel and they stared using the 28mm Bing and had a hose set up .
Title: Connecting Mikuni Spigot to 125 Head
Post by: KJDonovan on January 07, 2012, 06:25:42 AM
I didn't realize that was just glued on there, I will have to take a closer look at it today.  

Thanks,

KD

Kevin J. Donovan
Foster, Rhode Island
72 Jack Piner (My Ride)
72 Six Day (Wifes Ride)
73 Yamaha AT3
71 Suzuki TS125 (Project)