Vboost issue

[[email protected]]

I bought a 1986 Vmax in very nice condition. I read where I should hear the vboost solenoid cycle when I turn the key on. It didn't seem to do that. It seems some say the connector behind the left scoop sometimes get corroded and causes this. I took the scoop off and the connector was clean. I cycled the key and it seemed to work. I put the cover back on and it quit. So I took the scoop off and rerouted the the harness to behind another harness to prevent the scoop from coming in contact with it. I put it all back together and tested it maybe 10 times and it worked every time. I come out the next morning and nothing again. I'm told if I hit 6000 rpm there should be no doubt that it is working but I have doubt so maybe it's not. Anything else worth looking at before I take it somewhere?

 

[ga_max]

If I'm doing a gentle roll-on I don't notice the V-Boost kicking in. Only when I'm WOT do I feel it around 6500 - 7000 RPM. No idea what could be causing the issues but I'm sure others will reply.

Doug

 

[Fire-medic]

You could look at the wiring diagram, and see which circuit is the 12 V power to the stepper motor which opens the VBoost butterflies. Then you could see if you can hotwire the circuit to see the butterflies open. After that, hook a trouble light to the other side, and see if the circuit energizes, and illuminates the trouble light when the engine revs over 6K rpm. Of course, the first thing to do should be to follow the service manual instructions for trouble-shooting things.

 

[caseyjones955]

Mine does this thing where when I pack it back behind the scoop I have to do the key-on test to see if it cycles. If not then I have to twist it, turn it, put it on inside out or whatever to hold the wiring loom just right so that it works.

There is a fix where you disassemble the controller box to access the circuit board, strip some seriously nasty rubber stuff off the circuit board and re solder the joints where the harness meets the circuit board. I did that, and although I have read that it helped many others it did nothing for me and I'm pretty good with an iron. I'm still having to turn it or twist it and somehow it holds the wires just right and it works. No doubt I'll be throwing an ingitek TCI on the bike and use that to control the Vboost.


Every time I fire the bike up I listen for that to cycle, if it does not I have to pull the scoop and fidget with the harness until it works again. PITA but it's still my favorite bike.

 

[[email protected]]

As noted, the controller itself sometimes gets finicky. Sometimes, re-soldering the output wires on the circuit board will do the trick.

It didnt work for me. I bypassed the controller and wired it up to a double pole, double throw switch. I can turn it on/off as i like.

I bought an aftermarket v-boost controller from Sean @ Morleys Muscle. Its made by Micro Machines. I still havent installed it. The switch has been working for a couple years. http://micromachines.ca/vboost_controller.htm



Sent from my SM-G930V using Tapatalk

 

[gunrunner]

same thing is happening to me , but the vboost seems to be working . would of thought that it would have to do its start up cycle to set it going ??

 

[RempageR1]

The micromachines unit looks very expensive. If you were to buy an Ignitech unit for ignition AND Vboost, it would only cost you 144 USD....

 

[[email protected]]

I had the same issue and found a replacement stock board on ebay for $65. Best $65 I ever spent. It really woke the bike up.

 

[Sarvik]

Last year I bought a 1992 v-max. but it wasn't at full power, without a v-boost. Now I bought a new full-power engine without carburetors and v-boost inlet. I also bought a v-boost inlet separately, is it enough to make v-max full of power or do I have to do something more?

 

[MaxMidnight]

Assuming the carbs were from a restricted bike you would need to modify the slides.
If it was just the V Boost manifolds you acquired and if you also want them the perform as in a non-restricted bike you will also need the servo motor and cables plus the associated control unit.

 

[Sarvik]

Isn't that enough?

 

[MaxMidnight]

Difficult to tell - picture too small

 

[Sarvik]

Difficult to tell - picture too small

 

[MaxMidnight]

You have the butterfly assy. and the servo motor but appear to be missing the V Boost control unit.

 

[Sarvik]

this one?

 

[RempageR1]

Yes, that one. I`m unsure though if the non-full power VMAXES have the square plug you seen on that picture. The round one plugs into the Vboost servo you already have.

If not, it`s not that hard to create one if you are handy. Top of my head it just needs power and the pulse from the TCI to the coils. The same wire that connects to your tach.

 

[one2dmax]

I do have plenty of these components if you need one (or all of them). The servo is missing the main bracket to connect it to the CDI support bracket

 

[Sarvik]

I think I need only V boost control unit.

 

[Sarvik]

Yes, that one. I`m unsure though if the non-full power VMAXES have the square plug you seen on that picture. The round one plugs into the Vboost servo you already have.

If not, it`s not that hard to create one if you are handy. Top of my head it just needs power and the pulse from the TCI to the coils. The same wire that connects to your tach.

can you explain what this TCI is?

 

[one2dmax]

Transistor Controlled Ignition. Same thing as CDI or main brain box.