F**king carbs!!

[65fury]

Im stumped!! Ive never had an issue with this bike since i bought it minus a VR burning up. I recently went to start it after it sat for a month or maybe more and found it absolutely would not run with out the choke being on and any throttling just killed the motor. Keep in mind i road the bike 80miles before i parked without any issue and in the past ive had the bike sit for over 2months without ever starting it and never had an issue.

My bike is currently forsale and i even have a buyer whose suppose to be coming to buy it today!! I pulled the carbs to cleaned them up(never found any build up or junk in them when i did pull them apart tho) ended up breaking a tiny brass bolt but a HUGE thanks to Dannymax for sending me the partunk: I checked all the float levels and they were all pretty much set, i only tweeked one float to get it right, other than that the carbs have all stock jets and i changed nothing else.

The buyer has been waiting since thursday last week! but i couldnt assemble the carbs till id gotten the bolt which being memorial day weekend meant i didnt get it till tuesday.

Im having nothing but problems!! carb #2 the main one isnt showing ANY vaccum on my carb tune, and for the most part isnt even firing(getting spark tho) all other carbs seems to idle okay(with airbox removed only 3 slides oscilate/bounce at idle, #2 carb slide does not) when i install the airbox while the bikes idling the bike revs up to 5k! the idle screw for the whole carb rack is completely backed out yet my bike wants to idle at 5k rpms:confused2:

Ive removed and cleaned the #2 idle screw and removed the slide cover and blew air and carb clean thru it multiple times but still cant get that cylinder to idle.

Im stressing out, i need to sell my bike really bad(i have some serious finacial issues) and i have a buyer but if i cant get my bike running i doubt the guy is gunna wait another week......

Jason

 

[jfeagins]

Are your throttle linkages, and carb linkages between carbs all re-assembled correctly? It sounds like you may have a problem somewhere between those two places. +-really far out of sync.

I'd say "F**king gasohol" may be responsible for starting this unfortunate chain of events. The chit don't sit well.

 

[65fury]

Are your throttle linkages, and carb linkages between carbs all re-assembled correctly? It sounds like you may have a problem somewhere between those two places. +-really far out of sync.

I'd say "F**king gasohol" may be responsible for starting this unfortunate chain of events. The chit don't sit well.

Throttle linkage was never removed(i kept the carb paired together) only linkage removed was the throttle arm that goes from carbs on the left side to the carb on the right.

Also i could seem to get them to sync properly...... mostly cause the main carb you sync off of wasnt showing any vaccum on my gauge to match the other carbs to. When i tried bringing the other carb levels down to being close to the main carb(which was zero) i could only get them down so far before the adjustment screws bottomed out.... still not sure why my number#2 carb wont idle. i have Marks 4-2 exhaust and i can tell that its not even firing on that cylinder unless revved up and even then it misses really bad

Jason

 

[texas-ss-tornado]

Are the carbs seated all the way down into the boots? Sounds like you could have one massive vaccuum leak?? :ummm:

 

[65fury]

Are the carbs seated all the way down into the boots? Sounds like you could have one massive vaccuum leak?? :ummm:

Yeah, i checked with carb cleaner and couldnt find any leaks:confused2: Im pulling the carbs again and going thru them one more time.

With the Marks 4-2 exhaust should the main jets be changed?? or the floats set a little richer or leaner?? keep in mind i have marks 4-2 with custom short cans, they are each 6 1/2" long so its a very free flowing exhaust system.

Jason

 

[fmcandrew]

Jetting wouldn't explain that cylinder not firing at all unless it was clogged. If you know you have spark then you're down to 2 other possibilities...fuel & compression. If you pull the plug is it wet? if not then most likely it's a fuel/vaccuum issue...otherwise test compression to eliminate that variable...

 

[dannymax]

Jason, if your buyer will wait, you can send them up and I'll put 'em on the test bike to see what they act.

 

[65fury]

Jetting wouldn't explain that cylinder not firing at all unless it was clogged. If you know you have spark then you're down to 2 other possibilities...fuel & compression. If you pull the plug is it wet? if not then most likely it's a fuel/vaccuum issue...otherwise test compression to eliminate that variable...

I know jetting wouldnt explain the idle or missfire, but im still curious if the jetting could or should be changed for the marks exhaust, since im taking the carbs apart again anyways

I didnt check compression yet, its very unlikely thats it since before i pulled the carbs it ran on all 4 cylinders it just wouldnt idle without the choke being on. I did pull the plug and it was wet, i also tested spark and that was good even checked the gapping on the plug and that was also good.

If i spray carb clean into the carb while its running itll start firing again on that cylinder, and when revving itll fire on that cylinder also but it misses.

Jason

 

[65fury]

Jason, if your buyer will wait, you can send them up and I'll put 'em on the test bike to see what they act.

Hey Danny i really appreciate the help! hopefully ill get it fixed today, but if it comes down to it ill definitley take you up on the offer!

Jason

 

[Mr. Max]

You didn't lose that little o-ring under slide cover? High idle points to air leak or misplaced/pinched throttle cable or linkages. Throttle working normally? But if theres absolutely no vacuum at all, can it be only carb issue? I'd check compression from cylinder next..

 

[davesax36]

I vote pilot jets and really bad sync.

 

[[email protected]]

I vote pilot jets and really bad sync.

I second the motion.

Pilot jets might be so plugged it gets no fuel at idle. When you rev it up and start using a different circuit, it fires.

Id take the carbs off and go thru them again. Double check the pilot jets are clear. Hold them up to a light and check to see if light passes thru all orifices.

Make sure you put em together right. Easy to make mistakes if your in a hurry.

Put em back on, synch and check for air leaks

Sent from my SCH-I405 using Tapatalk 2

 

[davesax36]

There should only be one tiny hole in the pilot jet. That's the problem.... It's TINY.

 

[65fury]

okay so after i thoroughly cleaned them out... and im mean thorough!!! i had a florecent light to look thru all the jets with and they were good.

Its running... not right but its running and the carbs are sync'd only problem im having is idle to 2500 seems a bit lumpy and when i rev the motor up it the rpms hang and then slowly drop down.

While riding the bike GETS IT!!!! its faster than before forsure but the rpms hanging up isnt making any sense.... also my idle mixture screws are out 4+ turns otherwise it idles like ****


Jason

 

[PATMAX]

Wow, four turns out, that sounds like a lot for all four carbs. I've had one out that far but 2 -2.5 is more like it.

 

[leroycp]

Make sure the choke isn't "Hanging" Check each enrichener open and close

 

[davesax36]

What did you use to sync? Those settings seem way off, especially for Marks and a stock air box and jets. You should be at 147.5 mains and not 4 turns out.

 

[Mr. Max]

Maybe you misplaced some jets?? Is your sync now OK, you get vacuum for that carb?

 

[65fury]

Ill try to give a more detailed write up. The carbs have all stock jetting as far as i know, the jets are the same stock jets i had in the carbs on my last vmax.

Main jet #152.5(atleast thats what it looks like, the numbers are very faint)
PAJ1 #90
PAJ2 #170

definitely didnt mix them up either lol

stock needles and springs, and all the idle mixture needles are in good shape and clean.

When i first started to sync the carbs the #2 cylinder didnt seem to be firing consistently, if you put your hand over the muffler on that side it felt very weak and poppy compared to the other muffler which felt strong. The whole time i was trying to sync the carbs id blip the throttle but it would rev up and hang for a full second and then slowly slowly drop down to idle so it took forever to get them sync'd. I use a morgan carbtune which has worked flawlessly in the past.

I found that the idle improved and the exhaust notes where stronger the more turns out i gave the idle mixture screws. (ill check exactly how many turns out they are tomarrow) i found later i left the crankcase breather tube off and that seemed to help the rpms hanging up a bit... but i still feel like they dont drop quick enough, atleast compared to before.

Other than the RPMs hanging for longer than what i feel is normal... the bike runs amazing! very strong bottom end, mid range and top end! no issues except when cruising around 2k-3k it sounds a bit lean(random poppyness and crackle)

Also all linkage and plungers and every moving part moves smoothly, i double checked the rack before installed it and even after, nothing hangs up or catches.

Thanks!!
Jason

btw the buyer decided to plan on coming this weekend so i got till then to get this dialed in right!

 

[[email protected]]

I'd check the synch again. Hanging idle can be caused by synch.

A lean condition will cause it too. Air leak is a suspect. You can spray around with carb clean/starting fluid.....to check for leaks.

One item that gets overlooked is the rubber caps that cover the manifold vacuum ports. I would think they are eliminated as an issue though since you said it acts the same way with the caps removed and carb tune hooked up.