Vmax suddenly barely idles…won’t run

[blackbirdxx]

I admit that I don’t ride my max as much as I should, so now with that said, I think the bike is getting back at me. Everything had been working perfectly the last time I rode…then, I want to ride it after about a month and a half of sitting, and the bike will barely run. With the choke on, it idles but not very well, will not run at all with the choke off. When idling with the choke on, it doesn’t want to rev.

I have gone through the shotgun cleaning method and cleaned the carbs/jets the best I could. Interestingly enough, if it matters, 3 of the 4 idle mixture screws were set at 4 1/4 turns out (I left them that way when putting it back together).
No difference.
Other things I have done:
Replaced fuel tank
Replaced fuel filter

Still nothing has been able to work. I’m not sure if it is spark related but I guess I can try that next.

Anyone out there have any ideas?

I have a video of it running, but it was too big to attach. Here is a link to it on YT:

Thanks in advance for any ideas!

 

[Traumahawk]

It sounds like a definite clogged pilot jets, (because at idle and just running around town, that the circuit that the Vmax is running off of) and so taking them out, and cleaning them is needed. Ive had good luck with taking out PAJ#2, to get a full blast of air into the jets for a good shotgun cleaning.

 

[for_gdw]

i wont run right without the air box on!!

 

[MaxMidnight]

i wont run right without the air box on!!

But it will idle satisfactory when testing.

 

[Batlet]

It seems that you have problems with the pilot jets, they are probably clogged, to clean them you have to disassemble the carburettors. But to find out if that is the problem, you can operate the choke lever. If the performance improves with the lever operated, the problem is with the pilot jets, if there is no change, the problem is not the pilot jets.
(excuse my English level)

 

[jfeagins]

Did you check that the fuel pump had adequate outflow?

 

[blackbirdxx]

Thanks to all who have replied.

I have again used the "shotgun" method to blast out PAJs 1 and 2. It does idle a bit better, but only with the choke on. Checking the exhaust temps with an IR heat gun, it looks like it is only running on 2 cylinders....cylinders 1 and 2 are firing but nothing out of 3 and 4.

Spark is present on all cylinders and I have replaced all the spark plugs as well.

I have not checked the fuel pump output. I'll search for a procedure for that.

Trying to avoid needing to pull the carbs off for overhaul but maybe that is inevitable. This is what I get for letting the bike sit....even non-ethanol fuel has been used. The bike is full of 100LL now and that's what will be in from now on....