Wife's Vmax refuses to idle.

[Paul Matthews]

The wife's Vmax refuses to idle it's a 2001 model with only 5000 miles on it. It was fine last year when taken off the road. Didn't drain fuel doh. Tried the pea shooter method an with air box off and mixture screws out 2 turns it actually is trying to tick over. It will stall after a couple of minutes. Tried it a few times and was somewhat better. Reassemble everything and back to normal no idle. On this model according to Haynes manual the screws are 2.5 turns out. I only went back to original position. Should I try shotgun method and set mixture screws as per manual. Had one of these years ago 1986 Canadian one never any issue with the carbs.

 

[CaptainKyle]

It sounds like your pilot jets are plugged which requires the carbs to come apart. The jet blocks would need to come out and either new pilots or see if you can get yours clean. Several of us here do Mail in carb work if you are not comfortable doing them. I do them [email protected], Also Danny does them .

 

[Paul Matthews]

Sorry I am from N.Ireland and postage would be shocking. Are the pilot jets not at the mouth of the carb. Why does it run better with mixture screws out. What about the jets behind the diaphragm maybe they need a blast.

 

[Fire-medic]

Kyle is correct, often the pilot jets are plugged with hard deposits. They usually can be saved, but if someone previously tried 'fixing' them, and deformed the pilot jet hole, they need replacement. They are not expensive. Here is where they are. The jet block needs to be removed to remove the pilot jet, after removal of the carburetors.



Whenever I suspect carburetion issues, removal of the entire rack of four carburetors is what I do. An ultrasonic soak with the bits and pieces removed, and disassembly into two pairs of carbs is usually what works. If you need to replace the starter enrichment diaphragm, then the carburetor pairs need further disassembly.

This is the air bleed screw.



The awl points to where the air bleed screw end comes through the carb body.



The pilot jet with a stainless steel wire through the hole.

 

[Paul Matthews]

Kyle is correct, often the pilot jets are plugged with hard deposits. They usually can be saved, but if someone previously tried 'fixing' them, and deformed the pilot jet hole, they need replacement. They are not expensive. Here is where they are. The jet block needs to be removed to remove the pilot jet, after removal of the carburetors.

View attachment 89429

Whenever I suspect carburetion issues, removal of the entire rack of four carburetors is what I do. An ultrasonic soak with the bits and pieces removed, and disassembly into two pairs of carbs is usually what works. If you need to replace the starter enrichment diaphragm, then the carburetor pairs need further disassembly.

This is the air bleed screw.

View attachment 89430View attachment 89432View attachment 89431

The awl points to where the air bleed screw end comes through the carb body.

View attachment 89434View attachment 89433

The pilot jet with a stainless steel wire through the hole.

View attachment 89436View attachment 89435

Looking like it's requiring a carb stripdown. I have a Haynes manual and will follow instructions or removal. One question though is the statement correct about the mixture screws correct @ 2.5 turns out from fully in.

 

[CaptainKyle]

2.5 is a great starting point and usually about right although engines are basically just big air pumps and no 2 are exactly the same.

 

[Paul Matthews]

This will be a slow process as my wife has a multistrada that she prefers. Possibly the Vmax will be on its way out for sale.

 

[MaxMidnight]

If it runs better with the mixture screws out then the jets my not be fully blocked.
Before tearing the carbs apart first try one of the propriety cab cleaners such as Forte.
If that doesn't help then do the shotgun and only then consider stripping the carbs.
It may well be cheaper to invest in an ultrasonic tank than ship to a specialist?

The mixture screws were indiviually set at the factory to suit the demands of each cylinder. Unless the original settings were noted then 2 1/2 turns is a good starting point and can be fine tuned from there.

PS It would be helpful if you put your location on your profile.

 

[Paul Matthews]

If it runs better with the mixture screws out then the jets my not be fully blocked.
Before tearing the carbs apart first try one of the propriety cab cleaners such as Forte.
If that doesn't help then do the shotgun and only then consider stripping the carbs.
It may well be cheaper to invest in an ultrasonic tank than ship to a specialist?

The mixture screws were indiviually set at the factory to suit the demands of each cylinder. Unless the original settings were noted then 2 1/2 turns is a good starting point and can be fine tuned from there.

PS It would be helpful if you put your location on your profile.

Do you suggest I just run it with the cleaner in the petrol for a while. Or do I go and do the shotgun method now. I have put liguid moly motorcycle cleaner in the petrol. Or do you suggest another method of using it. I have used carb cleaner but only down the choke and top small jet at the carburettor Venturi. Going to invest in a compressor so I can give it a blast of air. Have used an air duster but suspect it's not powerful enough. As aside how do I edit my location as i seem only to be able to change profile picture.

 

[MaxMidnight]

Hi Paul, add the treatment to the fuel and see if that helps and if not move on to the Shotgun.

You can add your location by clicking on your name in the top RH corner, then Account details.