Yoshimura TMJ-MJN24 Carb
- Thread starter HymieP
- Start date
Grant's trail
Member
Hey Jamie, How much are they? I changed from the chinise carb to a mikuni, runs a little better since, also can now get jets for it.
I bought a brand new Holley Street Avenger 4-barrel carburetor with a lifetime warranty for my Rambler for roughly half of that price. Now there is one I have a hard time justifying.
reynolds_brad
Member
I have one on my 95cc motor and i have the MJN-Tm26 on my 115superhead APE. The Yosh carbs are by far the best carbs ive ever worked with. Not much else to say about them other then what i have on planetminis.
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I've yet to test one, however, the design speaks for itself. Adding an extended emulsion tube into the venturi should improve fuel atomization greatly, the #1 problem with running a big carb on these motors. Complete atomization is largely what gives fuel injection an advantage over carburetors. That said, the biggest mistake I see made in the quest for max power is oversizing the carb. Going 2mm smaller than port ID is a good rule of thumb for anything other than all-out racing. You've gotta go a lot smaller than port size before power will be restricted. As I've said about a bazillion times now, the absolute carb size limit is the diameter of the intake port. At this level, tuning becomes difficult - even for the experienced. Beyond that, the port itself becomes a restriction and the carb will never see enough airflow to function correctly. Since Yosh only makes them as small as 24mm, it's a non-issue for most engines. You may be able to "make it work", but it'll be mostly compromises.
Grant's trail
Member
I got it thru tmotorsports on e-bay It was around 30 bucks is it a real mikuni? I don't know it has mikuni cast into it and mikuni jets fit it. its a 26mm on a 160 lifan clone, all though a 24mm would probley work as well. I went up two main jet sizes, Idle jet was fine, clip in center grove. better responce then chinise carb only down side is the mixture adjustment is facing down. a little hard to adjust. I do believe you get what you pay for, and the much more expensive carbs are better units, but this one works better then the one that it came with, and fit my budget. I'll try and post a pic tomorow and maybe somebody can tell which one it is. :39:
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Grant's trail
Member
Surely, you jest!:24: If you cannot tell by looking, consider that wholesale cost on a VM26 is a helluva lot more than $30. The PRC outfits that manufacture these things are willing to put "Ralphkuni", "Keihole" or anything else into the casting mold. There's no law that says a knockoff absolutely cannot function well. A 26mm carb on a 160cc engine is a good match, small enough for adequate flow velocity at low revs and large enough to allow full power output. Mikuni rated their VM26for engines developing 25hp+. Even if your 160 only develops half that, it's going to flow enough air from idle through upper midrange to bring the fuel circuits to life...as you've seen. The bottom line is getting something that works.
No matter how badly one wants to believe that bigger is better, 26mm is just too bloody big for a stock 110 Nice. Put this carb on any stock 110 and the results will be lame-O. So, somewhere between the too-cheap-to-be-true / oversized-for-the-application VM26 knockoff and the still-oversized-and-expensive TM26 there must be a decent compromise. Something reasonably inexpensive and proven for the application. Oh yeah...the VM22.
Grant's trail
Member
I was pretty sure it was a knock-off, but so far has worked better then the junk that it came with. I'm going to try a cam change coming up, and I try a VM26 and let everybody know how it works for me. Thanks Bob for your thoughts I always enjoy your view on things Grant