Cams, who has 'em?

[Rusty McNeil]

Need advice or observations.

Who here is running cams bigger than stock?
With Mikuni carbs?
And with Vboost eliminated (stage 7) or open all the time.


Reason I ask is because I got the bike running really good at this point but no matter what I've done I can't get a happy idle that is pop and spit free, exhaust popping and carbs spitting, albeit only occassionaly.

I can't help but think its the overlap on my cams. If I close the Vboost it's perfectly well behaved.

I'm trying to work out a way to tie the Vboost butterflies mechanically to the throttle or else re-install the servo and use an output from my DJ WBC to drive the servo. I gave the controller away years ago.

Just wondering if I'm on the right track.

 

[KJShover]

Sorry can't help.
I'm running stg II megacycle cams, but I have a Morley kit and normal Vboost. No issues here.

 

[SpecOps13]

Wow, you need an RPM Controlled Servo Box. One that'll open the VBoost at maybe 1500 RPM. :ummm: A cable, user controlled would be a RPITA. Having the capability to close the VBoost sure would make syncing easier. That's the reason I don't go stage 7 with the 89.

Good Luck.

BTW, Kyle experimented with stage 7 and intact VBoost. I don't know if he'd have any ideas but it's a thought.

 

[Redbone]

Rusty, check with Maxcruiser (Mike) he put together a vboost controller on the LH grip using a gripshift unit from a bicycle. He used it to vary the opening of the vboost manually, and could turn off vboost at any point. Might be worth a try.

 

[CaptainKyle]

I am all for keeping the Vboost on stage 7 thats how im running now. it takes a bit more tuning but you dont lose all the low end & midrange.

 

[TnVmax]

I ran Stage-7 on my Tourmaster.
When I wanted to sync the carbs, I would pull the tubes and use rubber stoppers to plug the open intakes.

 

[SpecOps13]

Rusty, check with Maxcruiser (Mike) he put together a vboost controller on the LH grip using a gripshift unit from a bicycle. He used it to vary the opening of the vboost manually, and could turn off vboost at any point. Might be worth a try.

This sounds really Cool... Gotta find Maxcruiser...

 

[wildweasel_pt]

Use one of these... im considering using it with my DJ7 for syncing...

 

[Rusty McNeil]

I'm still leaning towards tying it to the carb linkage so it opens just off idle. Or reinstalling the motor and wiring up a momentary Polarity reversing switch. (two form C's)
The limit switches in the motor aren't too friendly as far as wiring up a simple controller circuit driven by my DJ WBC, they only close when at extreme open or closed. I started drawing one up and it started to require too many extra relays to be reliable.
Normal motor limit switches stay closed until at extreme travel making the circuit easier.
Shouldn't have given my vboost controller away years ago.
Plus I think my after market coils would need to be relocated to reinstall the servo motor.

 

[Redbone]

This sounds really Cool... Gotta find Maxcruiser...

Use one of these... im considering using it with my DJ7 for syncing...

Mike posted it as one of his first posts on the forum, I'll take a look-see to find the post.
UPDATE: I found it! Check it out here: http://www.vmaxforum.net/showthread.php?t=2198

 

[Fire-medic]

Seeing you use a GripShift for tensioning the VBoost cable for synching makes me think of using a choke cable ass'y. for the same thing. But, I read the link info and I think the GripShift is a good idea.

I recall when the GripShift co. released their product, I think it was about 1992-3. I had purchased a Klein Attitude 19" mountain bike, and it was built to my specs w/Shimano Deore XT. The next season it was outfitted w/Deore XTR when that became avail. I still have it, don't ride as-much as I used-to, I raced in some of the first offroad races held in FL @ the time. A lotta fun. GripShift was a brand-new co challenging Shimano, bit I always went w/the Trigger Shifters from Shimano, but many of the guys I raced against used the GripShifters.

This is an ingenious idea, I missed it the first time around, glad to see it mentioned again. I have a set of Stage 7 kitted carbs I haven't gotten-around to using. I profess to also like Kyle's idea of not eliminating the servo boost, and I know about just unplugging the VBoost when the system cycles open at the turn of the ignition key, & unplugging the connector, to leave the butterflies open. That's probably the easiest one of-all, but I like the idea of the manual control and being able to select what opening you want w/the left hand. Kinda like setting the spark advance on the old bikes. Thanks for posting it up again.

 

[mr.maxx]

seems like an easy project to fab a switch pod to activate the vboost motor. should be anyhoo.

 

[[email protected]]

I run the butterflies and servo but no controller. I just have the servo wired to a DPDT switch. Flip the switch one way and the butterflies open, flip it the other way and they close. Makes synching it easy. Once synched, I just leave them open all the time.

 

[Rusty McNeil]

I run the butterflies and servo but no controller. I just have the servo wired to a DPDT switch. Flip the switch one way and the butterflies open, flip it the other way and they close. Makes synching it easy. Once synched, I just leave them open all the time.

Are you using a momentary switch? Or did you incorporate the limit switches into the dpdt switch setup. I was playing with mine and it looks like one or the other could be needed to keep from putting power on the motor all the time.

 

[[email protected]]

Are you using a momentary switch? Or did you incorporate the limit switches into the dpdt switch setup. I was playing with mine and it looks like one or the other could be needed to keep from putting power on the motor all the time.

Momentary. I was just looking for a easy, and temporary solution to a broken vboost controller. Sometimes temporary becomes long term though.

 

[Rusty McNeil]

Momentary. I was just looking for a easy, and temporary solution to a broken vboost controller. Sometimes temporary becomes long term though.

I just found a dpdt center off non momentary to use. Just gonna have to remember to put it back in center position so as not to burn the motor up. radio shack suck now a days for that kind of stuff.
Still gonna look and see if there's a way to tie it to the throttle tho'