No Carbtune reading on #2 carb

[ultra93]

The exhaust temp is the same after warming up, and plugs are new and I just pulled them and they are all burning the same.

One thing I just noticed was the VBoost cable is loose at the lower attachment block where it connects the VBoost cable to that black box thingy. Could that have any effect on the issue?

 

[ultra93]

Upon further checking the VBoost cable slides up and down when the key is turned on & off. The engine will idle smooth at 1300rpm & above. Carbs 1, 3 and 4 are synced according to the carb tune, but still no reading by #2 on the carb tune.

I am stumped! Do not really want to pull the rack of carbs unless I have too. Keep thinking guys!

Also I put my palm over the #2 carb when it was idling and seems to have the same amount of suction as # 1.

 

[Traumahawk]

So when you blip the throttle inbetween adjustments....does the #2 slide on the carbtune move any?

 

[jfeagins]

The funny thing is 3 days ago when I did the 1st shotgun I had a reading on #2 carb on the carbtune, but it still would not idle without a little enricher on. So I gave it 2 more treatments thinking there was still some crap in the carbs. I wonder if using compressed air I caused something to blowout say on the enricher or something else on the vacuum side of the carb? Maybe Sean or Dannymax or Kyle or some of the other Guru's will offer some help when they login?

If you got carried away with blasting compressed carb cleaner into every orifice you can see in the carbs during that shotgun procedure, you may well have damaged one, or more of the coasting enrichener diaphrams. Don't ask me how I know this to be a possibility.


Get it over with, pull the carbs and go through them.

 

[alorio1]

The exhaust temp is the same after warming up,


Does that mean it's cold, not firing or hot ,firing??

 

[ultra93]

Both 2 & 4 exhaust get hot. The #2 car tune rod does move up about 1/4 inch when I blip the throttle. The other 3 got almost to the top of the carb tune.

 

[Traumahawk]

I would adjust 1,3, and 4 DOWN in the carbtune....and see if that has an effect on #2.

 

[ultra93]

Just tried that and it has no effect on #2. I have a feeling JFeagins is right I probably blew the enricher diaphragm on 2 when I was blowing it out. If it was blown would that effect the idle below say 1200rpms?

 

[ultra93]

Well, I'm going to pull the carbs and checkout #2 for vacuum problems. Wish me luck and many thanks to all for your advice. Is the a link to a good tutorial here on splitting the carbs? I have a Clymer manual but it is not that detailed!

 

[95spfldmax]

i am intrigued to hear the outcome of this issue........

 

[alorio1]

Well, I'm going to pull the carbs and checkout #2 for vacuum problems. Wish me luck and many thanks to all for your advice. Is the a link to a good tutorial here on splitting the carbs? I have a Clymer manual but it is not that detailed!

http://www.vmaxforum.net/showthread.php?t=12554

 

[johnpclynch]

Both 2 & 4 exhaust get hot. The #2 car tune rod does move up about 1/4 inch when I blip the throttle. The other 3 got almost to the top of the carb tune.

If the vacuum slide isn't opening as much as the others AND you're not getting a carbtune reading then it's either a large vacuum leak OR you're not pulling much of a vacuum on that cylinder - when you have the airbox off, put your hand over each carb mouth and turn the motor over, you should definitely be able to feel the difference

 

[jfeagins]

Just tried that and it has no effect on #2. I have a feeling JFeagins is right I probably blew the enricher diaphragm on 2 when I was blowing it out. If it was blown would that effect the idle below say 1200rpms?

In my case, that enrichener diaphragm was damaged by too much contact with the carb cleaner - causing the pass-thru orifices to become plugged, and also, sending small bits of diaphragm on down into parts of the idle circuits. When it happened, my bike wouldn't idle any less than 5k rpms, and was a ****** to get it to do even that.

The only good that came of my excessive carb cleaning that weekend was it caused me to FIND THIS FORUM for answers.....thus receiving an invitation to join in a Vmax rally at Eureka Springs, AR a couple weeks later.

 

[ultra93]

Have the carbs off and the #2 carb separated. Took the coasting enricher apart and the diaphragm is in great shape and the is nothing in the orfices that I can see. There is some outside cracking on the carb-manifold boots but then do not go all the way through to the inside. I did order 4 new boots anyway.

 

[alorio1]

Now would be a good time to take a compression test, which may reveal some thing out of the ordinary on that cylinder...

 

[MaxMidnight]

Rather than do a compression check it would be better if you could have a cylinder leakage test undertaken.
If there is an issue then you would know if it is bore related or valves.

 

[jfeagins]

Have the carbs off and the #2 carb separated. Took the coasting enricher apart and the diaphragm is in great shape and the is nothing in the orfices that I can see. There is some outside cracking on the carb-manifold boots but then do not go all the way through to the inside. I did order 4 new boots anyway.

How is the idle circuit in that carbs' pilot jet assy? Clear to see through, or plugged?

Choke plunger rubber still in good shape too?

You have it off, might as well go through them top/bottom & front/back while they are handy. Eliminate everything carb related before continuing on since you are this far.

 

[alorio1]

Rather than do a compression check it would be better if you could have a cylinder leakage test undertaken.
If there is an issue then you would know if it is bore related or valves.

Yes, a leak down test may reveal weather he has a broke valve spring, tight valve or ring blow by. Me being a pessimist by nature, as others have mentioned, a broke cam shaft. I know of two members on here that have had broke cam shafts, but I don't know if they reported their symptoms.

 

[ultra93]

Before I do a compression test, do I have to hookup the plug wires to the spark plugs and ground the plugs to keep fro damaging the CDI?

 

[alorio1]

No, it's ok to spin the motor with plug wires off not grounded........