v boost question

[HDKILA]

I saw the v boost post here:

http://www.vmaxforum.net/showthread.php?t=4361

My question is that when I tried this on my bike it cycled it through all the way up and down and then it seemed like once it got down it pushed back up a few centimeters...is that normal.

Also after cycling the v boost a few times with the key on/off it would not do it anymore...is that normal

My vboost adjustment screw does not have a rubber boot on the end as well...is that normal?

I am having trouble getting the screw. I am assuming I need to take the carbs off to get easier access. I won't screw anything up doing that will i?

Thanks again...

Abe

 

[4gasem]

It should do it every time you turn the bike on. As for the rest... Not sure.

 

[HDKILA]

I just opened my airbox and my filter had about 10 dead baby mice in it!

Yikes! That was the only thing the owner said he did not replace...

 

[Lew L]

I'll bet'ca he lied and it's just my 2cents but I would go through as much as you have time for. Brakes and suspension are a must.
Lew

 

[maleko89]

If you had that in your air box who knows what got down in the carbs.

 

[naughtyG]

That's what I think too. Discard anything the PO said as he was obviously bullshitting you to make the sale. :BoomSmilie_anim::blahblah:

If you had dead mice in there, you can assume that he didn't do any maintenance for a good while, and so the air filter needs replacing, your carbs will need to come off for a good clean and you need to check out that all the rubber boots etc are still in good shape.

 

[user 773]

Welcome to the "club"...

Regarding your VBoost cycling question (and take for granted this is one guy's experience):

My '86 exhibited the exact same behavior that you describe. Cycle full open, then close, then some random third adjustment. In addition, I had erratic engine behavior around the RPM that the VBoost should have been opening.

Turned out I had a couple things going on... First, the adjustment slide on the VBoost cable was missing the lock bolt (resulting in only partial operation of the butterflies). Second, and more important, my VBoost control module was shorting out and opening and closing the VBoost randomly.

First thing I did was to disconect the VBoost control module and verify that the performance improved fom a "stumble" standpoint. It did. I then replaced the stock VBoost module with an adjustable unit from these folks:

http://www.micromachines.ca

VBoost now cycles full open, full closed, and NOTHING MORE.

It is also adjustable from 2000RPM up to 6000RPM @ 250RPM intervals.

Not saying it IS your VBoost module, but it would explain the erratic VBoost cycling and may be the source of your "stumbling" behavior at high RPMs if it is opening and closing erratically due to a short.

Just my humble $.02

\m/ DS

 

[HDKILA]

Welcome to the "club"...

Regarding your VBoost cycling question (and take for granted this is one guy's experience):

My '86 exhibited the exact same behavior that you describe. Cycle full open, then close, then some random third adjustment. In addition, I had erratic engine behavior around the RPM that the VBoost should have been opening.

Turned out I had a couple things going on... First, the adjustment slide on the VBoost cable was missing the lock bolt (resulting in only partial operation of the butterflies). Second, and more important, my VBoost control module was shorting out and opening and closing the VBoost randomly.

First thing I did was to disconect the VBoost control module and verify that the performance improved fom a "stumble" standpoint. It did. I then replaced the stock VBoost module with an adjustable unit from these folks:

http://www.micromachines.ca

VBoost now cycles full open, full closed, and NOTHING MORE.

It is also adjustable from 2000RPM up to 6000RPM @ 250RPM intervals.

Not saying it IS your VBoost module, but it would explain the erratic VBoost cycling and may be the source of your "stumbling" behavior at high RPMs if it is opening and closing erratically due to a short.

Just my humble $.02

\m/ DS

I tried this as well to no avail...HELP!

 

[Thevmaxrider]

Sounds to me like you need to take the carbs off, check everything, clean the carbs, clean electrical connections, and the reassemble.

 

[RazoR333]

Welcome HDKILLA,...glad to have you on board,..this is the best DYI carb site that i have found ,..specially if you've never torn into carbs before,..check it out and keep us all posted.
http://vmax.lvlhead.com/tips/carb/walsh/walshcarbs.htm.
This dude has other good info on his site,..check it all out.
Take it slow ,..don't panic ,..take pics and notes if it helps,..

 

[Rusty McNeil]

I don't even have vboost but have worked on a lot of motor operated valves and gates and such at work.


Is it possible that the cable adjustment is such that when pulled all the way open

(the spring closes it right? the servo just unwinds the cable and allows the spring to close it?)

That when all the way open the cable is "too short" on adjustment so that when it reaches it's limit that when the servo is turned off excessive cable tension is pulling back slightly in the closed direction?

I'd double check the cable adjustments first, observe how tight the cable is when it's open and if anything is binding.

After that I might have a look at running the servo with the cable disconnected to see if the same problem or sound persists.

Or if it was me I'd just remove the servo and controller and wire the vboost butterflied open with a cable stop on the end of the cable. That's not for everyone tho'

Rusty