SuzukiSavage.com - 2006 S40 small jerks when keep my throttle steady

Afan

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2006 S40 small jerks when keep my throttle steady
03/23/17 at 09:53:59

Hi,
What could cause "jerking" when in 2nd or 3rd gear, keep the throttle steady and ride 20-35 mph? They are small, sometimes hard to feel, every couple seconds jerks. In 4th gear rarely, sometimes, hard to tell. Kinda the lower speed it is more frequent and "harder" jerks.
When accelerating it's ok.

The bike wasn't winterized the best way, but in last 2 months I rode couple tanks of gas with that gas cleaner thing and looks ok.
Battery is good.
I thought it could be the carburetor so I took it off and cleaned (even it was cleaned about 2 years ago).

Any idea what it could be? Where to start?
Embarrassed

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batman Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 3806 osceola new york Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #1 - 03/23/17 at 10:27:04 Sounds like your lugging the motor at 20mph you should be in first gear,35 is best in 2nd gear,you shouldn't go to 3rd unless you doing about 40mph.Torque peaks at about 3500rpm the speeds your trying to ride at the rpm is about 2200rpm (to low).
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Afan

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Re: 2006 S40 small jerks when keep my throttle ste
Reply #2 - 03/23/17 at 10:37:32

batman wrote on 03/23/17 at 10:27:04:

Sounds like your lugging the motor at 20mph you should be in first gear,35 is best in 2nd gear,you shouldn't go to 3rd unless you doing about 40mph.Torque peaks at about 3500rpm the speeds your trying to ride at the rpm is about 2200rpm (to low).

The way I'm doing is I would start in 1st, of course, and shortly after switch to 2nd. When reach 30 mph (or a bit before, depends if I'm still accelerating or ride on a slow road) I would switch to 3rd gear. Learned from my manual car and ST1100 I have too.

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justin_o_guy2

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Re: 2006 S40 small jerks when keep my throttle ste
Reply #3 - 03/23/17 at 10:38:56

Unless you're climbing a bit of a hill or pushing into a stiff breeze, you should be able to roll along in second at twenty, as long as the rear tire is not taller than stock. Very gentle acceleration should be fine from there. Same is true for thirty in third.
Try putting the choke on the first click and see if anything changes.
Is there any noise that coincides with the pulse?
Try setting the petcock to prime.
And, try holding a set speed in a lower gear.
See if Batman is onto something. Run a steady speed between 25 & 30 in second and see how it goes.

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Afan

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Re: 2006 S40 small jerks when keep my throttle ste
Reply #4 - 03/23/17 at 10:59:39

justin_o_guy2 wrote on 03/23/17 at 10:38:56:

Unless you're climbing a bit of a hill or pushing into a stiff breeze, you should be able to roll along in second at twenty, as long as the rear tire is not taller than stock. Very gentle acceleration should be fine from there. Same is true for thirty in third.
Try putting the choke on the first click and see if anything changes.
Is there any noise that coincides with the pulse?
Try setting the petcock to prime.
And, try holding a set speed in a lower gear.
See if Batman is onto something. Run a steady speed between 25 & 30 in second and see how it goes.

Ok. I'm gonna try all these and post if there is any difference.
Thanks.

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batman Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 3806 osceola new york Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #5 - 03/23/17 at 11:03:32 Afan ,you can't go by what your 1100 cc bike does,your single has to fire once every 720 degrees (the piston fires every other rotation )the st 1100 has a power stroke every 180 degrees,different animal!Just like our idle,you need to keep the revs up a bit higher on this puppy.
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Afan

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Re: 2006 S40 small jerks when keep my throttle ste
Reply #6 - 03/23/17 at 11:05:06

batman wrote on 03/23/17 at 11:03:32:

Afan ,you can't go by what your 1100 cc bike does,your single has to fire once every 720 degrees (the piston fires every other rotation )the st 1100 has a power stroke every 180 degrees,different animal!Just like our idle,you need to keep the revs up a bit higher on this puppy.

True...

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justin_o_guy2 Serious Thumper Offline What happened? Posts: 55279 East Texas, 1/2 dallas/la.	Re: 2006 S40 small jerks when keep my throttle ste Reply #7 - 03/23/17 at 11:16:12 OEM jets on a 2006 are gonna be small. In the lower gears the throttle opening at lower speeds may be still trying to use the idle circuit. You're just off idle. That's why I suggested the choke. Get a bit more gas in it and see how it acts. The stock petcock will get you one day.
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Afan Full Member Offline SuzukiSavage.com Rocks! Posts: 156 Des Moines, IA Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #8 - 03/23/17 at 11:40:23 justin_o_guy2 wrote on 03/23/17 at 11:16:12: The stock petcock will get you one day. I had installed Yamaha petcock as suggested on this forum. I'm selling the bike and every time I mentioned it they made sour face. So I put the original back on.
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Ruttly Serious Thumper Offline Thumpers Rule Posts: 5109 Manteca , CA Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #9 - 03/23/17 at 12:28:40 So was it ok with raptor petcock ? If so maybe it's the stock one you put back on !
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Afan

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Re: 2006 S40 small jerks when keep my throttle ste
Reply #10 - 03/23/17 at 12:38:01

Ruttly wrote on 03/23/17 at 12:28:40:

So was it ok with raptor petcock ? If so maybe it's the stock one you put back on !

No. it was the same with the raptor. Although, this is my very first bike EVER, and I bought it from a dealership. So, many of the bike "behaviors" I assumed it should be that way. After I put the raptor I didn't see any difference - what is not any good argument because, as a newbie, it would be hard for me to feel any "slightly" or less difference.

Last year, I hopped on the bike for old time sake and felt (recognized?!?) the jerking motions. In January this year it was really bothering me. I'm selling the bike - now it freaks me out! Grin

And, when I put the OEM back - no difference again. So, pretty sure it doesn't have anything with petcock.

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Afan Full Member Offline SuzukiSavage.com Rocks! Posts: 156 Des Moines, IA Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #11 - 03/23/17 at 12:44:06 As I said, I took off the carb and cleaned it. Checked and cleaned the membrane and the needle, float bowl, float needle, main jet, pilot jet... Didn't touch the air/gas adjusters (or whatever the name is). Could I screw up something while cleaning it?!?
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norm92de Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 1180 El Paso TX Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #12 - 03/23/17 at 12:52:38 Afan, You may have a lean misfire. What is your altitude above sea level? What JOG suggested may help if it is running lean.
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Afan Full Member Offline SuzukiSavage.com Rocks! Posts: 156 Des Moines, IA Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #13 - 03/23/17 at 14:31:34 norm92de wrote on 03/23/17 at 12:52:38: Afan, You may have a lean misfire. What is your altitude above sea level? What JOG suggested may help if it is running lean. I live in Iowa - pretty "low"
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Ruttly Serious Thumper Offline Thumpers Rule Posts: 5109 Manteca , CA Gender:	Re: 2006 S40 small jerks when keep my throttle ste Reply #14 - 03/23/17 at 15:06:55 Or a vacuum leak !
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