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#1

Show Off / Re: Not this forums typical 2 ...

Last post by Silky - Today at 10:36:43 AM

Any chance you could share the drawings please?

See if this works.  If not just google Boll aero plans.

https://modelenginenews.org/plans/BollAero18.pdf

That's fantastic, thanks so much 

#2

Turning Wrenches / Re: VM28 carbs

Last post by m in sc - Today at 10:31:33 AM

yes they will work but get genuine ones, stay away from ebay or amazon specials.

fwiw, summitracing has them for about 106.00 https://www.summitracing.com/parts/mku-vm28-49 but then youd have to set up for oil injection, jet, etc...

or, you can get the whole shooting match ready to go, jetted, fresh cables, etc, no guess work from john at economy.

https://www.economycycle.com/shop/yamaha-rz-350/fuel-and-airintake-yamaha-rz-350/carburetor-rebuild-kits-parts-related-fuel-and-airintake-yamaha-rz-350/carburetors-yamaha-rd250350400r5ds6ds7-parts-carburetor-rebuild-kits-parts-related-fuel-and-airintake-yamaha-rz-350/replacement-rd250-350-400-r5-ds7-carburetors-mikuni-vm-round-slide-series-28mm-carburetor-pair-includes-jetting-and-throttle-cable/

#3

Turning Wrenches / VM28 carbs

Last post by gargantua350 - Today at 10:13:57 AM

Hello All,

How are the new VM28 carbs?  I have seen them for sale in various places.   Mine are worn out and has bowl leakage that couldn't be solved with new gaskets. I think they are warped.  The slides seem completely worn out. 

My question:

with new carbs (vm28), Is the procedure for the DF mods the same as in the original carbs?  would I effectively get the same results?  Would it be better to just go with flat slides?  The bike btw runs great.  It's just these minor things I'd like to fix.  any opinions are appreciated.

set-up:

stock RD350 motor with Vitos crank
ProX pistons on std bore
Cheap cylinders from ebay
spec 2 classics
UNI air filters
HPI ignition at 1.8 mm BTDC
Main jet - 190
Needle #2 position from top
Pilot - #30
2.5 slide
1 turn out on air screws

#4

Turning Wrenches / Re: Pro-X piston ring question

Last post by Striker1423 - May 21, 2024, 10:50:32 PM

I put one on my RD250 top end when I first rebuilt it. Never gave me trouble, but ditched them on my next set after taking with Chuck as well.

#5

General Chatter / Re: RIP Frame Maker

Last post by svgarage - May 21, 2024, 11:23:33 AM

Perfect! Thanks for bringing up that video, Ken.

#6

General Chatter / Re: RIP Frame Maker

Last post by kpke - May 21, 2024, 08:57:40 AM

That was this ride. The Frame Maker show and tell begins at about 8 minutes.

#7

Turning Wrenches / Re: Pro-X piston ring question

Last post by SoCal250 - May 20, 2024, 08:40:56 PM

One of Chuck's recommendations from 2019: "Another tip on Pro-X pistons kits is throw the 2nd ring wavy expander in the trash, don't use it!"
From the many discussions over the years about these, now every time I hear about a ring expander I always think of Chuck saying "toss that ring expander where it belongs, in the garbage!" It's burned into my memory now.

#8

Turning Wrenches / Re: Pro-X piston ring question

Last post by 2steve - May 20, 2024, 07:33:08 PM

I kept the expander out.

And Chuck Quenzler would tell you to do just that.

In fact, the exact quote was, "I forgot to take the expanders out before I shipped. Throw them away!"

#9

General Chatter / Re: RIP Frame Maker

Last post by svgarage - May 20, 2024, 05:16:58 PM

Last Summer, Julian and a small group of us Yamaha 2-stroke bikes had a great ride up and down one of the local mountain roads. Afterwards we all mustered at his house, where he pulled out some of his masterpiece motorcycles in a show-and-tell of sorts. All his creations had a story to tell. A couple of months ago, he invited me to his shop to show me where all the magic happens. Such a brilliant mind! And he was so open and sharing. One of the nicest guys I've ever met. I'm going to miss him. RIP Julian.

#10

Turning Wrenches / Re: Pro-X piston ring question

Last post by rdsarefun - May 20, 2024, 12:13:39 PM

Hi Mark,  I made a typo when I took a pic and placed the rings on the instructions.  I have these installed correctly as the ring land on the piston prevents a mismatch.  I kept the expander out.  See below in italics:

I made a typo though, the second ring is thicker, wanted to clarify for future reference  Second ring is .059",  top ring is .046"