Author Topic: Two minute mod ?  (Read 8420 times)

Offline Bluegray

  • Jr. Member
  • **
  • Posts: 34
Two minute mod ?
« on: May 13, 2011, 02:32:00 pm »
Unfortunately the forum died with the wealth of info. A buddy just bought a Connie after seeing
How well mine performed. He was riding a HD no wonder. His bike's PO had the mod and the bike performs great. He showed us where he had placed a portion of sponge in the carb opening. Will the sponge work by itself or will I have to do other things too? I know Steve had done work on his carbs also.

Offline norcalbarney

  • Jr. Member
  • **
  • Posts: 39
  • Country: 00
  • I got me an '86
    • Bikes, bro
Re: Two minute mod ?
« Reply #1 on: May 13, 2011, 02:40:20 pm »
I shoved a used dish sponge in, covering about 2/3rds of the right side.  I have the jet kit coming, but I wanted to try the original method first.  The buttdyno shows increased low end torque, smoother power from 2500 - 4000 rpm, and less noisy when starting cold.

Offline pat8228

  • Jr. Member
  • **
  • Posts: 50
  • Country: us
Re: Two minute mod ?
« Reply #2 on: May 13, 2011, 02:58:36 pm »
Im new to this, and I've never heard of putting a sponge in the carb. What does it do? Will it hurt anything? More information on this would be appreciatied.

YoDoc

  • Guest
Re: Two minute mod ?
« Reply #3 on: May 13, 2011, 03:00:08 pm »
I second this more information thing.

Offline norcalbarney

  • Jr. Member
  • **
  • Posts: 39
  • Country: 00
  • I got me an '86
    • Bikes, bro
Re: Two minute mod ?
« Reply #4 on: May 13, 2011, 03:08:40 pm »
Here's a link to use Google to search the old forums, in this case for "2 minute mod".  You'll need to click where it says Cached.

http://www.google.com/search?rls=en&q=site:concours.org%202%20minute%20mod&hl=en

Hope this helps!

Offline toojeep4u

  • Jr. Member
  • **
  • Posts: 57
  • Country: us
Re: Two minute mod ?
« Reply #5 on: May 13, 2011, 03:10:09 pm »
The two minute mod involves blocking a portion of the airbox off from fresh air.  This in turn makes the bike run smoother.  It makes a vast improvement on low to mid range torque and all but eliminates the stumbble all COnnies seem to have in th 2k RPM range.  It does however cause the bike to run rich, so rejetting is the next step.  Steve in Sunny Florida can clean, rejet, bench balance, and install overflow tubes for $300 shipped.  I had it done this winter and the improvements are nothing short of fantastic.  Well worth the money!
Tori '01

YoDoc

  • Guest
Re: Two minute mod ?
« Reply #6 on: May 13, 2011, 03:26:03 pm »
Mas powah? I think I'll wait on that. I'm coming off a Harley, and this bike is already a better ride than I am a rider. :)

Offline medicevans

  • Full Member
  • ***
  • Posts: 137
Re: Two minute mod ?
« Reply #7 on: May 13, 2011, 04:14:37 pm »
IIRC, SiSF originally asked other people to try the "sponge in the airbox" technique to test on other bikes what he had experienced on his own bike.  Here is what SiSF has said in a previous post:

"....if the only concern was to produce maximum full throttle power, then the most un-obstructed airpath would obviously produce the highest numbers. In this case, there's a whole lot more to the picture. As you know, small carbs have always been used to produce torque, but the price is limited top end power. The carbs on the connie fully support the stock power output, and larger carbs don't help, but that "bigger is not always better" theory didn't translate when Kaw fit the gpz900 airbox (high rpm engine) to the midrange tuned connie engine. By restricting the intake, the part throttle response is really sharp and snappy, which is where most riding is done. The result may be that the WOT power is the same as stock (though i SERIOUSLY doubt it) but the part throttle power is so good the bike really feels much more powerful. If the dyno runs (wot) follow those of my bike, even the dyno sees the torque increase below 5000. The hardest part for anyone to wrap thier head around is that WOT HP is really not all that useful to everyday riding. "

I have the 2 min mod w/"power" rejet and the exhaust sprocket Steve offers.  I'm telling you, if you at all can, spend the money.  The kit has totally made me do a complete turn around on this bike.  Power is completely linear now, still a little boost when you hit the power band, but no stumbling around below 3k RPM like before.  The big thing is, MORE USABLE TORQUE and USABLE "POWER" whatever power means to you.  It makes all the difference to the bike. 

YoDoc, I can second the difference between the Conc's I4 and a HD v-twin.  I might kill myself on this bike before it's all over.  Holy cow. 

Offline Bluegray

  • Jr. Member
  • **
  • Posts: 34
Re: Two minute mod ?
« Reply #8 on: May 13, 2011, 04:40:05 pm »
Will this decrease mpg?

Offline throb

  • Full Member
  • ***
  • Posts: 214
  • Country: us
Re: Two minute mod ?
« Reply #9 on: May 13, 2011, 07:05:45 pm »
Should have no effect on mileage if you ride the same way as before.  Problem is, since the bike runs so much more smooth and responsive, you will probably have a tendancy to be a little more liberal with the throttle than before.  This will equate to lower fuel economy, but a bigger &#$( eating grin on your face,  Which is worth more?    ;D 

I have SISF jet mod too, and as stated before, if you can afford it, do it!
'05 Concours, SISF's 2 min jet mod and exhaust cam sprocket, snarf's block off plates, risers, SS lines, fork brace, T-Cro's stick coils & shift linkage, ZZR1200 rear shock, MS rear wheel.

Offline Steve in Sunny Fla

  • Full Member
  • ***
  • Posts: 1111
  • Country: 00
    • Shoodaben Engineering
Re: Two minute mod ?
« Reply #10 on: May 13, 2011, 07:11:18 pm »
  There's a constant misunderstanding that anything that makes more power kills fuel economy. That's simply not true, if you're able to make things work more efficiently. That's what I've always tried to do.  there's no reason the 2 minute mod jet kit or sprocket would negatively impact your mileage - but if you start having more fun with the better performance and get silly with the throttle, yeah, your mileage will go down - but that's up to you, not the improved tuning. Steve

Offline Lodogg2221

  • Full Member
  • ***
  • Posts: 179
  • Country: us
Re: Two minute mod ?
« Reply #11 on: May 13, 2011, 07:14:31 pm »
Actually, with regard to mileage, some riders have reported an increase, though slight (read that on here before the crash Im pretty sure). 
It wont take it down though for sure, unless you enjoy the new found feeling, and are using your right wrist more! 
And that of course is the great thing.  Better response, a bit more power, and in better places too, and no hit on mileage like some "normal" jet kits would have.

Of course the above assumes you are not just stuffing a random piece of foam in the airbox, but rather going with the kit. 
I dont know about the foam only, but Id think if you are going to just make it richer, your mileage will drop, though maybe not significantly...

I am still "adjusting" (trimming to the correct size, a little at a time) the foam included with my kit, and man this thing surprises me sometimes! 

Best $300 you can spend on your Connie in my opinion....
Say what?

Offline Bluegray

  • Jr. Member
  • **
  • Posts: 34
Re: Two minute mod ?
« Reply #12 on: May 13, 2011, 07:36:03 pm »
The bike my friend purchased had steve's kit and you are right The performance of the bike is worth
the money. I hope to get my carbs done by Steve in the future but until then if the sponge will work I will try it.  The addition by Steve to stop a hydro lock is worth the money also. It is good to know even though the forum crashed the knowledge is still here. Thanks folks for the help.

Offline Steve in Sunny Fla

  • Full Member
  • ***
  • Posts: 1111
  • Country: 00
    • Shoodaben Engineering
Re: Two minute mod ?
« Reply #13 on: May 13, 2011, 07:42:14 pm »
Keep in mind that by adding the foam and not re-jetting, you are going to hurt the fuel economy because the mixture becomes to rich. You will notice improved power in the lower rpms, not from the richening but because the foam is helping the airbox dampen the reversion pulses. Over 5000 rpm, and the higher you go, the more the excessively rich mixture will hurt performance. Yuo can add the foam as a TEST  fr the increased lower rpm performance, but know that without the proper jetting, you're not going to help the efficiency. Steve

Offline Bluegray

  • Jr. Member
  • **
  • Posts: 34
Re: Two minute mod ?
« Reply #14 on: May 13, 2011, 07:59:48 pm »
Thanks for the additional info Steve that Is good to know.