Problem with VBoost (electricity)

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi Sean,
When you say "geared motor" you mean the VBoost servo motor?
Your engine looks great but I can't test it - so frustrating! I'm limited to "Harley" speed :)
 
Yes, sorry I should have clarified. Try this test. Turn on the key and listen for the servo to go through it's cycle. If you hear it go all the way open and closed (which is normal) then let's try this next step.

Once you know it's going through a normal cycle we are going to have you stop it in the "open" position. Turn the key on and after you hear it start to open turn the key back off before the cycle completes.

Unplug the connectors on the black box previously shown (I usually unplug the round connector but either one should work). This will force the vboost to remain in the open position at all times.

Then see if the bike will start and run. If so that will at least give you back the full power until you can figure out what's killing it.

Sean
 
Thanks. I'm going to try it tomorrow morning.
BTW the servo cycle consist of 2 or 3 phases (sounds)? if 3, which is the opening phase?
 
2 sounds. Whirrr, Whirr is about the best way to describe it. You can bend down and look up into the area and watch the cable retract.

Sean
 
OK Guys, here are the updates:
This morning I went to my mechanic and we tried to figure out what's the problem. We used the information provided in this thread and this what we have done:
1. Disconnect the VBoost round connector - problem remains
2. Disconnect VBoost square connector - problem remains
3. Cleaned corrosion from connectors - problem remains
4. Disconnected the ignition switch and bypassed it - engine works fine!

So, our immediate thoughts were that the problem is with the ignition switch and it must be fixed. I'm in the process of ordering NOS ignition switch from one of the members here (my mechanic wanted to fix it by I simply don't trust the quality of the results...)

One thing which bothers me though... how come that the engine shuts down precisely at 6k rpm? I would expect it to happen at random values. This consistent behavior made me think it's a VBoost problem at the first time...

Thanks a lot for your help. I will update you when I get the new ignition switch installed.

Adi
 
Maybe, but I can't tell for sure because I can't observe it while riding. But in my opinion it's not vibrating noticeably more.
 
Could very well be corrosion. At lower rpm's the ignition system has a higher current output than at high rpm's. If there is corrosion present as the rpm's go up they eventually hit a point where the current flow through the circuit is so low it cannot "overcome" the resistance in the circuit and it shuts down. The 6k rpm is just where this happens. Of course I may be talking out my backside, need someone who knows this stuff inside out to comment.
 
CLEAN IT OUT!!!! I have a thread in the How To section. You may be able to find the loose connection and simply just resolder. At least open it up before spending the cash on a new one. It is very easy and will save you the $200 that'll prolly cost you.

How To: Recondition the Ignition Switch
 
Last edited:
we tried to do that in the garage today but not as thorough as described in your post (which is fantastic I must say).
I'll try to do that tomorrow morning.
 
Am very curious as too what fixed your problem. Any luck?

regards from my tapatalking android...
 
Thank you very much for your interest. I read your tutorial and didn't find so far in any store the "dielectric grease" and "dry lube". The direct translation to hebrew doesn't help much. I don't want to start without having all stuff needed. So far I have multimeter and contact spray.

BTW the problem now happens more often in any RPM not just 6000.

Cheers!
 
Thank you very much for your interest. I read your tutorial and didn't find so far in any store the "dielectric grease" and "dry lube". The direct translation to hebrew doesn't help much. I don't want to start without having all stuff needed. So far I have multimeter and contact spray.

BTW the problem now happens more often in any RPM not just 6000.

Cheers!

don't worry too much about the dielectric grease and dry lubricant at the moment. just clean off any corrosion and dirt from the contacts and put back together. test out the rebuilt switch. the "lube" is just to help keep the moving parts lubricated. you should be able to go at least a week without the "dielectric grease" and "dry lube". i have a feeling that you might have a loose solder joint somewhere--not necessarily in the ignition switch, but it is a good place to start. open up the switch. it isn't difficult to put back together.
 
OK Guys, here are the updates:
This morning I went to my mechanic and we tried to figure out what's the problem. We used the information provided in this thread and this what we have done:
1. Disconnect the VBoost round connector - problem remains
2. Disconnect VBoost square connector - problem remains
3. Cleaned corrosion from connectors - problem remains
4. Disconnected the ignition switch and bypassed it - engine works fine!

So, our immediate thoughts were that the problem is with the ignition switch and it must be fixed. I'm in the process of ordering NOS ignition switch from one of the members here (my mechanic wanted to fix it by I simply don't trust the quality of the results...)

One thing which bothers me though... how come that the engine shuts down precisely at 6k rpm? I would expect it to happen at random values. This consistent behavior made me think it's a VBoost problem at the first time...

Thanks a lot for your help. I will update you when I get the new ignition switch installed.

Adi


Dude,

If the switch fixes it for you, what I think is that there is some part of the switch that is having a "harmonic" vibration. I can't explain it easily with words, but if you know guitar or can get someone to show you a harmonic, you might get an idea. That part might have a length which is a multiple of the wavelength of the note that your engine "sings" at 6000 rpm!
What that then causes is the dirty contact or bad solder joint that others have mentioned to pop apart enough (and be dirty enough) to shut it all down.

Whatever! Pffft.


The problem with the switch was already there, and maybe vibration made it worse. Sounds like your isolation testing (above) is pretty sound! :clapping:

Happy riding!! :biglaugh:


BTW This is supposed to be good --> http://www.crcind.com.au/switch-cleaner-lubricant
 
OK Guys, here are the updates:
I'll start from the end - the switch and the bike are working FINE!!!!! Thanks to the Ninja and the other members here.
I followed the tutorial, took the switch apart and examined it. the problem was not corrosion or dirt but rather the white contact armature (see section 12-13 in the tutorial). for some reason one side of it was melted (it's made of plastic) and as a result the spring didn't work - actually it was stuck. I released it, cleaned all the other components as explained and reassembled it. now it works fine! however, I would like to replace the white contact armature since it's in a bad shape and probably will make me trouble in the future again.
Is it possible to buy just that part and replace it or it is better to buy new switch? There is one NOS switch with a fair price for sale in this forum.

Thanks for your help again,
Adi
 
That is the exact same thing that had happened to me and was the inspiration behind my tutorial. I fixed it the first time the same way as you had done. It happened to me a couple more times until I replaced the whole switch assembly with a rocker switch. I have no true reason or explanation as to why the armature kept on melting. My best guess would be the cracked ignition block that sits right under the ignition switch. If your curious of my "rocker switch" workaround, go into the User Mod section and look for my thread on the subject. If you ever do figure out the cause, I will be VERY interested.

regards from my tapatalking android...
 
You cannot buy just the piece, you'll have to buy a whole assembly. You'll have a second key mind you. Plus unless you figure out why it melted in the first place, the next one will melt as well. Good luck

regards from my tapatalking android...
 
I have a "few" used switches in the stockroom (yup they suck). I'll look this weekend and see if that part is good on any of them. I'll let you know ASAP.
 
Back
Top