[latebird]

2005 500HO
carb over fueling, remove carb, clean, install oem carb kit, r/r fuel filter. no more fuel leaking from bowl but have fuel spraying out of the Air jet on front of the carb (intake side). Did i miss something when i reassembled the carb, is there any adjustments that are needed on the jets for this make of carb.
Thanks

You obviously missed something or caused a problem during assembly or installation - if a crumb of soil accidentally enters the fuel inlet nipple during fuel line installation, it may prevent the float needle from shutting off fuel when the float rises causing a mysterious flooded float bowl on a freshly rebuilt carb. Kinda like a surgeon leaving an instrument in a patient - sometimes it causes a problem and sometimes it only results in setting off a metal detector in a restricted access location. Sometimes a crumb of soil keeps the float needle open, sometimes it obstructs the opening and slows fuel delivery and sometimes it flushes through and spends it's life laying on the bottom of the float bowl.

 

[crazypj]

He stated fuel is coming out of air jet, if float was stuck it will come out of breather, overflow and various jet discharge ports. Highly unlikely to be dirt in shut off valve. On Mikuni carbs (and a few others) the air bleeds in intake (air box side) are lower than discharge ports. Early Mikuni (VM, etc) have drilling directly to emulsion tube (or primary choke) which is lower than the actual fuel discharge ports. It's most likely OP assumed a genuine repair kit didn't need float level checked and just installed new parts (or checked float level incorrectly?) I taught this stuff at MMI and every dealer workshop I ran before that.
There is nothing wrong with trying to help, but read at least some of the previous posts first (I didn't read all118 previous as this problem was 'recent' and not original 2010

 

[latebird]

He stated fuel is coming out of air jet, if float was stuck it will come out of breather, overflow and various jet discharge ports.

Just where is the air jet located? I identify the 'air jet' as the inlet of the air passage for the idle circuit on the inlet side of the carb. You obviously correctly identify the air jet as something else.

Now imagine that you are a 14 years old and trying to describe a carburetor problem. What do you identify as the air jet?

I am not a Mikuni Guru, but have repaired thousands of carbs with my first experience working on a Zenith side flow updraft carb on a 1949 Case SC tractor. I have repaired nearly every brand of carb you can think of and some you may have never heard of. The list includes Carter, AFB, FOMOCO, Holley, Mikuni, Keihin, Amal, Delorto, Bendix, Walbro, Simplex, Kun Fu, HuaYang, Huayi, Sun, Sun World, DENI, KF, HLIC, MIC and some with no name. One of my specialties is replacing damaged over flow pipes in float bowls and I replace the common welded seam brass tube with seamless stainless steel surgical tubing.

I did not teach at MMI, although I have been invited to accept a position there which I declined. I have worked in various dealerships and have successfully operated an independent repair shop since 1978.

Yes, if the float is stuck, fuel will come out of all the ports including the float bowl vent depending on the volume of the flow. I made a suggestion with an explanation, so how do you suggest the poster address the issue? Add some helpful info and not just browbeat those who try to give insight to the novice.

Your suggestion to address the issue is:

 

[crazypj]

My best suggestion is to post a picture of the 'offending' part.

It would give us a much better idea of what the problem is.
Glad to hear you have had a successful business since 1978, I was working as a precision machinist then (trained so I could make BSA parts fit my Royal Enfields, BSA parts were much easier to get hold of.)
I've got various carbs here but grandson has run off with camera (don't like using phone)
Pretty much everything since mid 70's EPA mandates will be a little different
Mikuni's on a 1968 Suzuki T305 (worked on one Saturday so it's first thing that came to mind) are almost the same as the VM's sold today but 'New' CV carbs are very different (Harley kinda messed things up by having Mikuni and Kei-Hin brand carbs as HD and removing all external and most internal brand markings)

 

[crazypj]

Oh, here's an old Kei-Hin (mid 70's) The air box connects to left side and carb connects to engine on right side.
The model and type will be on carb somewhere although Mikuni tend to have very ligfht etch or 'print' as it's cheaper than stamping. I've worked on just about any carb you can think of (including Jikov, Bing and HD 'chainsaw' carbs)
It may not be easy to 'fix' a carb long distance but it wouldn't be the first or last time I've done it

 

[latebird]

Yeah, I forgot about the Bing carbs on my 57 Zundapp KS601

And the air jet is where?

 

[crazypj]

I'll find some pics.
Your probably as old as me so know there are few 'new' techs/mechanics that understand carbs and want to plug 'everything' into a computer for 'diagnostics'
I've pretty much exclusively worked on bikes since 1968, I know plenty of 'factory trained' mechanics who can only do things 'by the book' (and are mainly very good at it) but, often you have to think 'outside the box'
One thing I have found in last 5~10 years, float levels need to be at least 1mm higher than stock to compensate for E10 being 'thinner' (less dense) than non alcohol fuels. You may remember test kits being sold to check for alcohol fuels in the 70's?
Personally I think it's evil stuff being foisted on us by farming lobby. It isn't 'cheaper or more cost effective plus results in higher fuel consumption

 

[crazypj]

We still need to know carb make and model. It's 'probably' a CV carb but guessing isn't smartest thing to do?
Anyway, more pics cos' people like them (these are all old stuff but I can find them)
The 'air jet map' wasn't done by me but shows location of air jets and corresponding fuel jets.It's a representation of vacuum chamber on top of carb looking straight down (by Trek97 on DTT)
Honda has used 3 jet carbs since the mid/late 1960's and majority of people STILL don't understand them. (CB250/350 twins, etc) 1978 on they got more 'complicated' and way more difficult to tune or modify from stock settings due to EPA fines (although not as bad as Yamaha's $26 million fine a few years ago)

 

[crazypj]

OH, the 'map' is actually incorrect, the piece marked 'Intake' should read 'to air box'

 

[latebird]

Yeah - alcohol - is thinner, but it's not the farmers - put blame where blame should be - the alcohol producers and their lobby want alcohol in fuel. The Farm Bureau, the corn growers association and the petroleum producers are all against alcohol blended with gasoline and diesel fuel. Farm fuel does not contain alcohol because it so expensive to repair alcohol in farm equipment, alcohol is not in marine gas because the alcohol is toxic to marine life and commercial aircraft fuel is banned from containing alcohol.

The new crop of mechanics may never know what a carburetor is - it's all computers and fuel injection.

 

[deatonoutlawmotors]

Hey I have a 2002 polaris scrambler 50 it was running pretty rough so I replaced the carb, reed valve, intake, air box, spark plug and coil. I got it to start on time I noticed it would only idle at normal rpm with fuel choke. I drove it around to get it hot and the idle would drop so low it almost died a few times. I turn the it off and adjusted the air and fuel screw and it never would start again no mater what position the ifel screw or the mixer screw is in. I tried starter fluid and it will fire but not start. I have good spark. I lost on what is going on it ran better with the bad parts but won't run with the new. Thanks

 

[FPD218]

Hey I have a 2002 polaris scrambler 50 it was running pretty rough so I replaced the carb, reed valve, intake, air box, spark plug and coil. I got it to start on time I noticed it would only idle at normal rpm with fuel choke. I drove it around to get it hot and the idle would drop so low it almost died a few times. I turn the it off and adjusted the air and fuel screw and it never would start again no mater what position the ifel screw or the mixer screw is in. I tried starter fluid and it will fire but not start. I have good spark. I lost on what is going on it ran better with the bad parts but won't run with the new. Thanks

to the forum

 

[haganzel]

View attachment 175391 to the forum View attachment 175390

I have converted a Xplorer 250 to mixed gas from injected and I have read that the jetting needs to be changed when this conversion is done. My machine continues to operate, but is fouling the plug rather quickly. Do I need to increase or decrease the size of the main jet? Do I need to do anything to the pilot jet?

 

[latebird]

Is the plug oil fouled or gas fouled? If you changed the jetting, what did you change it from and to?