Sudden burst of OMG power

[Dragonslayer]

I took a road trip to Augusta, Ga. and back this weekend (2 1/2 hrs one way). the bike has been running fine. While there I got rained on for a few minutes. But, on the way back it developed a little accleration ( I hesitate to call it a problem) more like an accleration surprise. While acclerating at cruising speed all of a sudden it would sputter a little bit then launch with a sudden burst of power that would lift the front wheel off the ground and launch the bike forward like it had NOS and someone flipped the switch. .......OMG was my first reaction.

 

Thinking it might be carbureation on the next fill up I bought a can of seafoam and poured 1/2 a can in the tank to see I could clear out whatever partial blockage was in the carbs. Evidently there is some unrealized power potential in this bike I haven't witnessed before and I would like to figure out why and harness it full time.

 

Today, riding to work and back I tried to duplicate the experience everytime I had some accleration room ahead of me so that I could watch what was going on closely. Everytime I was acclerating in any gear and the RPMs reached 4500 to 5000 it would launch up 1000 to 1500 rpm with an incrediable boost of power and seemed to keep going untill I backed off of the throttle.

 

Does anyone know what might be causing this?

[painterman67]

just an idea but mine( 91 vr ) was doing the same thing. Muffinman finally figured it out that I had a bad cdi and was only running on 3 cylinders. MIne would sputter and get that sudden exceleration at 3 grand. Changed out the cdi and all was better.

 

Turned out that the cdi would kick the 4th cylinder on at 3grand or so.

 

 

DAvid

[RandyR]

Vboost....

 

[Yammer Dan]

"Shades of the "Blue Beast" Bob. I still got that TCI somewhere. Like you said first time it done it was in 2nd and front wheel came up. Never could get that one to do it when I wanted it to. Thats why Skid still has bragging rights!!!! But I got "Brown Sugar" now!! Already changed TCI on her once and got a new one coming!!!

THANKS DINGY!!

[dingy]

Your welcome, I think ??

 

 

Gary

[bobcat]

I'd suggest before you run out and buy a new TCI that you unplug your current one, spray the contacts with electrical contact cleaner then plug it back in...

 

As a matter of fact, any time I have an electrical issue that's the first thing I do..unplug and plug the offending part..It's worked on everything from the fan, to heat guage, to speakers, on board compressor, alternator (big white plug)and so on..

[XV1100SE]

Sorry if I'm off base.... 2nd Gen here.

Possible it has something to do with the carbs? Isn't there something else in the carbs that opens when you get to a certain throttle position? Possible one or two of the carbs is sticking until it gets to a certain throttle position or vacuum at a certain rpm?

[skydoc_17]

Hey Don,

In the Carbs. the secondary circuit would shift to the primary circuit at around 2500 RPMs. I have seen a burst of speed in that range if the secondary circuit is clogged.

It does sound like a fourth cylinder is "lighting off" at higher RPM, most likely due to a wet TCI. Think of a 25% power increase when the tach. hits the "Magic RPM Number" and the 4th cylinder lights off. WOW! Hook up with Dingy, sounds like he has the cure.

Earl

[Dragonslayer]

I'd suggest before you run out and buy a new TCI that you unplug your current one, spray the contacts with electrical contact cleaner then plug it back in...

 

As a matter of fact, any time I have an electrical issue that's the first thing I do..unplug and plug the offending part..It's worked on everything from the fan, to heat guage, to speakers, on board compressor, alternator (big white plug)and so on..

I agree, I did do that and the problem got a little better but did not completely correct itself meaning that I have more consistant low end accleratrion and the high end accleration starts at a lower rpm (about 4000) But still sputters before it kicks in at 5000rpm. I just want it to run 100% all the time so I'm looking forward to the new programable TCI Dingy is putting together.

[Dragonslayer]

Hey Don,

In the Carbs. the secondary circuit would shift to the primary circuit at around 2500 RPMs. I have seen a burst of speed in that range if the secondary circuit is clogged.

It does sound like a fourth cylinder is "lighting off" at higher RPM, most likely due to a wet TCI. Think of a 25% power increase when the tach. hits the "Magic RPM Number" and the 4th cylinder lights off. WOW! Hook up with Dingy, sounds like he has the cure.

Earl

Name is Bob,

 

But I agree I have an order placed with Dingy for the new TCI Mod.

[Dragonslayer]

Sorry if I'm off base.... 2nd Gen here.

Possible it has something to do with the carbs? Isn't there something else in the carbs that opens when you get to a certain throttle position? Possible one or two of the carbs is sticking until it gets to a certain throttle position or vacuum at a certain rpm?

I guess it is possible but I have spent a lot of time focusing on the carbs and am within about 2000 miles of a total work through on the carbs after a Valve shim job. I'm pretty confident on the valve shim adjustment, Carb work through and carb synch. I'm betting TCI I've seen how tempermental they are to many times before.