V-Boost died. Help fix please...

[Shuriken]

Well, I've had the bike like 4 weeks. V-Boost worked long enough for me to feel it a couple of times. Now I noticed today that it's not working. I do not have any servo sound when I turn on the key.

I have checked and have cleaned all of the wiring contacts. I have even checked the V-Boost circuit board inside the black box. I have voltage on the 3-pin connector going to the circuit board. I have looked around but haven't found other things to check.

Anyone have any ideas? The V-Max is just V-Average without V-Boost...

 

[Shuriken]

So there is the control unit and the servo motor. Looks to me like the control unit takes signals from the ignitor box and/or ignition coil and probably allows voltage to the servo motor at 6k.

So I should be able to test each component separately, right? I don't know how one can test the control unit - anyone know? Should be able to apply voltage to the servo to see if it functions, right?

Anybody have any specific info on this? The manual wasn't very helpful.

 

[Shuriken]

Found this thread:
http://www.vmaxforum.net/showthread.php?t=3249

Is there a way to test the servo and the control unit to know for sure? Looks like the unit is like $224 new and the servo motor is around $200.

 

[Shuriken]

And found these threads:
http://www.vmaxforum.net/showthread.php?t=1774&highlight=servo
http://www.vmaxforum.net/showthread.php?t=821&highlight=servo

 

[one2dmax]

Ouch, If it's the servo motor I have a few on hand. The black boxes are more likely the culprit most of the time but aren't terrible with our discount.

You can fix it cheap by using a screwdriver and propping it open (look into the side and use the screwdriver to move the black connector up the slide). You'll have to manually close it again if you want to sync the carbs.

Sean

 

[maxcruiser]

Or for about 30 bucks - you can make a manual boost like I have and get rid of all the vboost electrical stuff - simple and fool proof - just the way I like it.

I had a vboost control box die on me - opened it up and it was the solder on a diode that let go - resoldered it and it was fixed - for me if I pressed on the box (near the plug in) while the key was on the vboost would work - soon as you let go it would stop working.

Just a thought.

Mike

 

[Shuriken]

Thank you for the tips. I already found my way into the V-Boost control last night after pushing on the controller housing and getting a really faint gurgling sound from perhaps the motor.... The black plastic housing on the underside of the circuit board looked like it had been heated. I dremeled off the resin as much as I dared and then peeled the rest of it off to get to the circuit board. I resoldered 2 spots that looked bad but that didn't seem to make any difference.

To me, it should be as simple as first making sure the servo motor works by applying voltage; if that doesn't work, there is one problem; if it does work, it's definitely the controller....

But what servo motor wires do I apply voltage to?

 

[maleko89]

Apply power here.

 

[Shuriken]

Thanks everyone for the help.

I found the problem.

It is positively the V-Boost controller board. If I apply a slight bend to it the servo can be made to open and close. Chalk another V-Boost problem up to "I've never heard of a servo motor going out" comment that I read earlier.

Looks to me like there are many pins that need resoldering. I have soldering experience and a low-heat gun, but I sure don't like heat around those logic chips.

In case I can't resurrect this unit, does anyone have a known good spare for sale?

 

[lankeeyankee]

Or for about 30 bucks - you can make a manual boost like I have and get rid of all the vboost electrical stuff - simple and fool proof - just the way I like it.

I had a vboost control box die on me - opened it up and it was the solder on a diode that let go - resoldered it and it was fixed - for me if I pressed on the box (near the plug in) while the key was on the vboost would work - soon as you let go it would stop working.

Just a thought.

Mike

For about .03 cents you can by a zip tie and keep the V-Boost open!
I never understood such the big hype over the V-Boost.

 

[Shuriken]

Well, after about 2 hours of careful soldering, V-Boost works. We'll see how long it lasts.

 

[Buster Hymen]

Well, after about 2 hours of careful soldering, V-Boost works. We'll see how long it lasts.

:thumbs up: That's great news! :clapping: It should stay working now. I believe the original problem stemmed from poor soldering from the factory.

 

[Shuriken]

Heck yes. I found about a dozen pins that looked as if the solder had cracked in small rings. Probably soldered more than I needed to, but it works for now.

I'd like to reseal the circuit board. Anyone done that?

 

[4gasem]

Heck yes. I found about a dozen pins that looked as if the solder had cracked in small rings. Probably soldered more than I needed to, but it works for now.

I'd like to reseal the circuit board. Anyone done that?

Having worked on PC boards for years I have seen that a million times. Easy fix. Just melt the existing solder and you're golden. No need for more.

 

[Shuriken]

Should I try to reseal the underside of the board with some kind of glue, resin, silicone, etc?

 

[Neil-3446]

Only if you don't plan on opening it again soon.

I like the zip tie idea mentioned earlier, and they sound like this on idle with open headers.

http://youtube.com/watch?v=xPqRUTTYWWE

Neil

 

[shawn kloker]

Neil,Was that a quart of Kentucky moonshine I saw sitting on the step stool in your video?

 

[lankeeyankee]

Yupp sounds good. I leave mine idle at 1500. I havent used VBOOST in years. I just zip tie it open. The onlytime I close the VBoost is to snych the carbs. V-Boost doesnt increase any power or performance gains if you have your bike tuned properly and I think I can prove that with running 101 MPH in the 1/8 with a stock motor and carbs on a street tire

 

[maleko89]

True, for individual air filters. Stage 7 has you unplug the vboost to make up for midrange loss.

 

[johnpclynch]

My VMax started off without boost, I got the linkage and hooked it up with a choke cable. Looks like this

Last week I got a servo motor and it's waiting to go in