3 replies [Last post]
ktistis7412's picture
VBMWMO #7412
Joined: 08/20/2008
Posts: 2

Good evening.
A few weeks ago i bought a R51/3.Runs pretty good.She's in a great condition.
BUT.....she's wearing a 25mm dellorto carbs.
no matter how I've tried i can't time them.they work sometimes fast and sometimes slow.
the smoke is nore black,nore white.the color is good.
can someone tell me the right timing?
i 'll be glad to hear some news.
FREE ride for everybody here in Greece. Wink [/b]

Darryl.Richman's picture
VBMWMO #6285
Surf City, USA (Santa Cruz, CA)
Joined: 10/27/2006
Posts: 2185
dellorto carbs on R51/3

I don't have any experience with Dell'Ortos on this bike. My R51/3 had R60/2 carburetors on it when I bought it (24mm; the originals are 22mm). It was impossible to use the throttle until the bike was completely hot, or it would stall. Otherwise, it idled great and ran ok, with a stumble off of idle.

Your carburetors are even bigger, so I would think you would have even more trouble when pulling away from a stop.


VBMWMO Webmaster,--Darryl Richman

oligee7275's picture
VBMWMO #7275
Joined: 05/31/2007
Posts: 79
dellorto carbs on R51/3

Hello K in Greece,
Your translation here is a little interesting but we'll work through it.
It would help if we knew which carbs you have on the bike. Look on the carbs and see if you can find a number that tells style and model of carb.
You can look here http://www.mypage.tsn.cc/rdd/TT/contents/CARB/dellorto/index.html
to find more information on setting up your carbs.
You say it runs good so I assume you mean that it is fast and slow at idle.
I assume that when you say "time" them you mean "balance" them.
When they run fast or slow it could mean that they are simply out of balance in which case follow the instructions in the link above.
Also check to be sure that the gaskets between the carbs and the head are not leaking and are in good condition. These gaskets not sealing well could cause it to be hard to balance.
Like Darryl said, those carbs are big for that bike which could be causing you to have trouble balancing them. The bigger carbs can be made to work if the internal jetting is correct for your application.
Let us know how it is going,

ktistis7412's picture
VBMWMO #7412
Joined: 08/20/2008
Posts: 2
Dell'Orto on R51/3

Hello again.
I think i found the answer to my problem.
I change the 25mm with a pair of 22mm carbs.
now i have a better result and the engine works softer and smoother.
Thanks to everybody who offer his assistance. Wink

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