Carburator time ?

snowman71

snowman71

New member
Well for a change this christmas there will be some snow 4 to 6 inches . So I went to try to start up my 79 srx 440 . Have not run it for 2 seasons so i done the usual and a couple of squirts of gas down the spark plug holes . After a repeat it started . Then noticed it running rough and i hear fluid so i looked and the right carb overflow T is flowing out gas ??? So i shut it down and go figure whats up . All I can come up with is its time to pull off carbs and clean them . Any tips what else to look for ?:xmas-smil
 

Get em clean. Probably a stuck float or needle seat. If it's been sitting two years your probably lucky is was puking fuel out the vent. If you ran it you may have burned down the engine. Two years is two to long for a carb to sit with fuel in it.

opsled
 
No I didnt burn the engine down maybe 25 seconds at the most . It was run last fall once when i tried to sell it and ran ok then .
 
Todays gas sucks man. Clean the carbs and get some good fresh stuff in thereand you should be good.

opsled.
 
is there a drain plug on the crankcase ? bet i got fuel down there also .

Yea fuel setting by itself without a conditioner added is trouble waiting to happen . I didnt think gas with 2 stroke oil added would become as much of a issue .
 
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No drain plug. You can get most of it out through the intake once the carbs are off. Rotate the piston up and use a bulb pump or something like that. You will likely foul a couple of plugs until it clears while getting it going.

opsled
 
OK , now i call the yamaha dealer for carb kit and they dont know if I have a HR or HD carburetors .... I know the manual says vm36's Whats the diff between HR & HD's ? I see no other tags on the carbs while on the machine .
 
The carb #'s are on the front side of the choke horn right where the choke plunger screws in. If they are the OEM 79 carbs the #'s should be 8JO-OOL (left clutch side carb) and 8JO-OOR (right recoil side carb)

If they need more than the #'s from that location they don't know what they are doing.


Chances are you don't need any parts just a cleaning. Needle/seats maybe but it's verey rare to need much more unless they are really effed up.

I'd take them apart and see before I ordered any parts.

opsled
 
opsled said:
Chances are you don't need any parts just a cleaning. Needle/seats maybe but it's verey rare to need much more unless they are really effed up.

I'd take them apart and see before I ordered any parts.

opsled
Click to expand...

+1..!!!!
 
I think the parts person dont know a tillotson from a mikuni myself after i hung up the phone and got to thinking on it . Whats a good website to order mikuni parts from ?
 
I literally make a big part of my living by doing carb work..I`ll bet the farm that you dont need any new parts..

A can of carb cleaner, a decent tooth brush, and a Q tip, and you`ll be back in biss..

not matter what carbs you have, I`ll bet I can post pics of identical carbs peice by peice on my work bench in my home garage..So dont worry about getting things apart then having an issue getting everything back together right (not that there are many parts in um anyway)..plus you can and should just do one carb at a time, that way you have the other to confirm part location etc..float hieght is`nt a big deal, thats easy to check adjust etc..
 
OK I have a question , can i soak these carbs with what looks like a white nylon or plastic T's on in the solution ? ( plastic is a no no i read ) These dont come off it appears .
 
I use a water based cleaner made by Gunk. Comes in a white 1 gallon can. Part # is CC3K

I have two cans so I can soak two carbs at once. Washes off with water. Doesn't hurt plastic, rubber or gaskets. Much cheaper than the old smelly toxic stuff I used to use and does as good or better job of cleaning.

If what you are using says no plastic beware. It will probably eat it.

Thos plastic elbows and such on those carbs do come out but are pressed in and may break trying. Not something you want to do unless you have to.

opsled
 
since i am waiting for o ring kit , what size fuel line works ? A 1/4" ( 6mm ) fits loose on the stem and a 3/16" ( 5 mm ) is tight already on the stem without sliding over the barbs ?
 
When you get your fuel line soke the end in hot water and it will slide on e-zy
 
been to darn cold this winter to set my carbs back on but would like some input on the power jet adjusting screw on the fuel bowl . Service manual says 0 turns and air bleed 1 turn So if I don't run it at sub zero temperatures , hard and wide open I can leave the main adjuster screws closed ? (vm36's)
I use the recommended 15:1 fuel to oil ratio with yamalube

latest read is the main power jets are closed to get machine running , then tune as needed for high speed end . Wish I knew what it was set at before cleaning :frech32:
 
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