Carby advice please. | Yamaha SR500 Forum

DOUG (gopher)
New Member

Posts: 23

Carby advice please. May 2, 2007 23:05:04 GMT -5

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Post by DOUG (gopher) on May 2, 2007 23:05:04 GMT -5

So here is the story, I put my bike in to get serviced and to have a look at because it was running rough and rich.

The verdict was the original Mikuni Carb was really worn so I decided to get a new Mikuni carb which I'm asked for a VM 36. and after a month I finally got my beloved SR back. This guy doesn't seem to work very fast...

The advice I need is:

The carb that he intalled requires the fuel switch to be in the PRIME position because it's not a vacuum carb. Is that normal???

Also I have been trying to start my bike today and it just started pissing fuel from I'm assuming the Carb overflow tube (the tube that hangs off the carb and points down to the crankcase) is that normal as well??

I'm really wondering if he bought the right carb for my SR?? because it's harder to start now.

thanks in advance

DOUG

milkman
Senior Member

Posts: 967

Carby advice please. May 3, 2007 6:02:19 GMT -5

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Post by milkman on May 3, 2007 6:02:19 GMT -5

Just from reading around here mate, i've seen something about needing a vaccum line ?? attached to your carby to make it work properly in the "on" position, otherwise you need to be in prime mode.
Stew will be all over that.

Carbs are the dark art I dont like to dable in......

aero
Senior Member

Posts: 267

Carby advice please. May 3, 2007 6:10:20 GMT -5

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Post by aero on May 3, 2007 6:10:20 GMT -5

The manifold he has fitted is wrong, it should have a vacuum take off to allow the tap to work. I changed the non vacuum manifold on mine as it is a pain not having reserve.

I don't have the jets for 36mm carb, but these are the STARTING sizes for the 34mm. You will need to adjust these to suit your own set up.

200 main
30 pilot
P8 needle jet
60DH Needle
2.5 throttle slide
#2 air jet

Set the pilot screw 2 1/4 turns out, she'll start then

You can see the vacuum line on the top of the manifold.

Last Edit: May 3, 2007 6:17:39 GMT -5 by aero

StewRoss
Senior Member

Posts: 2,334

Carby advice please. May 3, 2007 6:57:13 GMT -5

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Post by StewRoss on May 3, 2007 6:57:13 GMT -5

Hi,

The XS650 (I think it is...) manifold has the vac line already in it for carby balancing...should go straight on to the SR and run the carby line to it...alternatively a machined up spigot could fairly easily be placed into the SR's manifold as well.

www.mikesxs.net/mikesxs-fuel_system.php?category_id=4.7

SR

...'Any unnecessary items on the bike, that it doesn't really need, shouldn't be there!'. (Café racers creed). SR...

DOUG (gopher)
New Member

Posts: 23

Carby advice please. May 4, 2007 1:51:11 GMT -5

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Post by DOUG (gopher) on May 4, 2007 1:51:11 GMT -5

Well I worked out one of my problems...

Dirty fuel tank and because I've got to run the fuel in the PRIME pos it grabs all the crap from the bottom of the tank.

I pulled off the float tank and it had the equivalent of a pinch of dirt in the bottom. Cleaned it out and blew out the carb and I got her started.

I think running the vaccum setup is the way to go then I get my reserve tank back.

thanks for all the advice