Sport cruiser keihin tuning

[INDebtSJ]

Well I am at wits end with this carb. Can't figure it out and need some help.

Stock 650 with coffman pipe and water box.
Removed the large intake box thingy for more air flow. Stock carb 38mm.
Symptoms are not getting on plan or going past 4400 or so rpms. 2 peeps.
I can add a hint of choke and it will run like it should. It has done this since the beginning. I have lowered the pop off. Increased the pilot jet from 58 to 60. Same thing. Went with a 122 main. I had 2 1/2 turns out on the air screw.
Just installed the 125. Have 2 turns out and is worse than before. Add a little choke and it runs great.

Idles great .starts great. With the 122.5 in it , it would pull from a dead stop to 200 feet and fall on its face.
Most I get on choked rpms is 5700 to 5800 rpms.

What does anyone suggest? I am tired of choking my chicken!

Current set up is 60 125. Don't remember the pop off but is lowered.

 

[Ducky]

Want me to send you the 38 I took off my newer chicken to see if it does anything for you?

 

[INDebtSJ]

Want me to send you the 38 I took off my newer chicken to see if it does anything for you?

I am going to keep trying. I just turned the high out some more and it has gotten better. I still has a real bad left turn syndrome. I am trying to lean the low out to see if that rids that. I think the left turn syndrome is it being lean for some reason. Choke it and its fine. Who knows.
If you would hurry up and get yoursome running good on the 44 I will just copy ur jetting !

 

[Sasquachcrap]

You took out throttle signal by reducing the restriction which was your factory air box. That's why it clears up Wien you add a little choke. What was your original pop off and what is it now?

 

[INDebtSJ]

You took out throttle signal by reducing the restriction which was your factory air box. That's why it clears up Wien you add a little choke. What was your original pop off and what is it now?

I can't remember exactly now but I think it was high 20,s to 30. I replaced it with a spring that came in my rebuild kit. It was the shorter of the 2. I want to say it was in the teens.

 

[Sasquachcrap]

So did you use a pop off tester to check it?

 

[INDebtSJ]

I did. I just can't remember lol.

 

[INDebtSJ]

So did you use a pop off tester to check it?

Are you leaning toward pop off. If so I did order some springs from jets r us. I can change it out. I think one of the ones I ordered was in that rebuild kit I used.

 

[Sasquachcrap]

I would think that 26-28 would be close. Have you tried putting the box back on to see if it clears up.

 

[Sasquachcrap]

Some times to high of pop off will keep you from transitioning to the high circuit. Try and drop it 10 more psi and see if that makes it worse or better. I like going to far to get a noticeable result. Then you can come back a little if you need to.

 

[INDebtSJ]

I would think that 26-28 would be close. Have you tried putting the box back on to see if it clears up.

I have the air box. I will try that too.

I will go on paypal and see if I can find the grams in the springs. I know it was lower that the 20,s

 

[SmittySX]

You shoulda bought mine..

 

[INDebtSJ]

Some times to high of pop off will keep you from transitioning to the high circuit. Try and drop it 10 more psi and see if that makes it worse or better. I like going to far to get a noticeable result. Then you can come back a little if you need to.

Ordered some of 40 gram and a 70.
Pretty sure I used the 40.

 

[x2mafia]

I went through the same issues with our sc and the airbox was the culprit put her back on and it works great. The first thing I did was rip it off and I never even considered it a problem

 

[Ducky]

Just go with the 44. Start with 150 high, 120 low.

 

[INDebtSJ]

I went through the same issues with our sc and the airbox was the culprit put her back on and it works great. The first thing I did was rip it off and I never even considered it a problem

Then that's what I will do!
I enjoyed trying to tune but without some sort of guidance or more experience it is frustrating.
I am amazed how right turns the rpms would go up and slight left turn the rpms would drop by hundreds.

 

[Sasquachcrap]

I may have a 44 I can part with. I can even jet it to your liking. Pm me if interested.

 

[INDebtSJ]

Just go with the 44. Start with 150 high, 120 low.

I will have to start looking for a manifold .
May do the Yamaha conversion at some point. I have a big bore group k 685 in my vxr that I don't use anymore.

 

[Ducky]

I will have to start looking for a manifold .
May do the Yamaha conversion at some point. I have a big bore group k 685 in my vxr that I don't use anymore.

You can find a carb adapter for about 30 bucks that enables you to use your stock manifold, and then you just dremel out the opening to match the size of the carb!

 

[INDebtSJ]

You can find a carb adapter for about 30 bucks that enables you to use your stock manifold, and then you just dremel out the opening to match the size of the carb!

That's way cheaper!
What do you do with the throttle cable?