SuzukiSavage.com - White spacer mod question

Sheriff41

Junior Member

Offline

SuzukiSavage.com
Rocks!

Posts: 88
O'ahu, HI

White spacer mod question
02/13/14 at 23:31:20

I did the white spacer mod on my '07 S40's carb to get rid of the off-idle flat spot/hesitation. The bike is all stock except for the Raptor mod and the idle mixture screw access.

I took the stock spacer out and replaced it one half as thick. After putting everything back together the bike started and ran fine. I warmed it up in the driveway and then shut it down for the night.

This morning it started up fine and after warming up ran really good for about 5 miles on the way to work, no flat spot on acceleration and smooth power. Then, after stopping at a stop light it would die as soon as I twisted the throttle. I was able to keep it running as long as I pulled the choke all the way out. After work I was only able to drive it with the choke pulled out.

Could the slide be hung up and causing this?

Back to top

IP Logged

Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18098 Camp Springs, Kentucky Gender:	Re: White spacer mod question Reply #1 - 02/14/14 at 05:08:53 When it doesn't run at idle.....it is most likely something wrong in the Pilot Jet circuit. The Pilot Jet and the idle air screw have tiny holes and it doesn't take much to plug something up.
Back to top	Someday I will be old......But not today! IP Logged

Sheriff41 Junior Member Offline SuzukiSavage.com Rocks! Posts: 88 O'ahu, HI	Re: White spacer mod question Reply #2 - 02/14/14 at 07:23:24 Thanks Dave! I was thinking the idle circuit is okay since it will start and idle perfectly without the choke (sorry, I wasn't clear on that above). It just stalls out when I open the throttle unless I pull the choke out. It runs great with the choke! I'll check the jets when I open it up again.
Back to top	IP Logged

Dave

YaBB Moderator
ModSquad

Offline

SuzukiSavage.com
Rocks!

Posts: 18098
Camp Springs, Kentucky
Gender: male

Re: White spacer mod question
Reply #3 - 02/14/14 at 07:34:11

The "choke" is actually an "enricher", and it adds some fuel only at very low throttle openings. If you need to apply the fuel enricher (choke) to get the bike to run, it indicates there is not enough fuel flowing at lower throttle settings (pilot circuit).

Removing part of the white spacer or putting in a few washers raises the needle, which results in a richer mixture from about 1/8 throttle up to about 3/4 throttle.

What have you done with the idle fuel screw? Is the brass plug removed and can you remove the screw to clean the carb.....and adjust it to set the idle mixture.

Back to top

Someday I will be old......But not today!

IP Logged

Sheriff41 Junior Member Offline SuzukiSavage.com Rocks! Posts: 88 O'ahu, HI	Re: White spacer mod question Reply #4 - 02/14/14 at 07:44:58 Yep, pulled the brass plug out previously and was able to adjust the mixture screw. Right now I have the mixture screw turned out just over two full turns for best idle.
Back to top	IP Logged

old_rider Serious Thumper Offline Backyard Bill Productions Posts: 3147 flordia panhandle Gender:	Re: White spacer mod question Reply #5 - 02/14/14 at 13:55:56 Doesn't the choke just constrict air flow to create more vacuum to draw more fuel from the jets? If so, he might just need to clean the passages in the carb.....
Back to top	We are here to laugh at the odds and live our lives so well that Death will tremble to take us. IP Logged

Gyrobob Serious Thumper Offline Posers ain't motorcyclists Posts: 2571 Newnan, GA Gender:	Re: White spacer mod question Reply #6 - 02/14/14 at 20:52:57 old_rider wrote on 02/14/14 at 13:55:56: Doesn't the choke just constrict air flow to create more vacuum to draw more fuel from the jets? If so, he might just need to clean the passages in the carb..... This bike does not have a choke. It has a mixture enrichment device. There is no choking off of airflow.
Back to top	If you think there's good in everyone, you haven't met everyone. IP Logged

Sheriff41 Junior Member Offline SuzukiSavage.com Rocks! Posts: 88 O'ahu, HI	Re: White spacer mod question Reply #7 - 02/14/14 at 22:07:34 Well, I'll pull it apart in the morning and see what I find. If anyone else has ideas on this please post 'em up here!
Back to top	IP Logged

Steve H

Serious Thumper

Offline

SuzukiSavage.com
Rocks!

Posts: 1223
Spartanburg, SC
Gender: male

Re: White spacer mod question
Reply #8 - 02/15/14 at 07:12:38

Check the jet needle. Sounds like something's not right there.

When I got mine it started and idled wonderfully. Soon as you gave it any gas, it would sputter and backfire and eventually stall if you kept the throttle open. Turned out the PO had "cleaned" the carb and put the needle in wrong. Not saying you put it in wrong...but something might be loose or sticking with the slide.

Just a thought. Hope it doesn't send you on a wild goose chase.

Back to top

87 LS650, 2005 Ninja 250, 2009 Yamaha C3, 2001 Honda Reflex. On 2 wheels since 6/80.

IP Logged

Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28660 Tucson Az Gender:	Re: White spacer mod question Reply #9 - 02/15/14 at 07:25:19 Steve H wrote on 02/15/14 at 07:12:38: Check the jet needle. Sounds like something's not right there. +1... When you make a change, and something ain't right, it's usually 'cause you did something wrong... Retrace yer' steps... Also, clean the slide... ...
Back to top	Ludicrous Speed !... ... ... IP Logged

Sheriff41

Junior Member

Offline

SuzukiSavage.com
Rocks!

Posts: 88
O'ahu, HI

Re: White spacer mod question
Reply #10 - 02/15/14 at 11:59:35

Ok, here is what I found to be the problem: After removing the piston valve and making sure everything was clean, I dug a little further. Turns out the washer on top of the jet needle spring somehow got bound in the bore and was keeping the jet needle from moving freely in piston valve. I reassembled the jet needle in the piston valve and made sure it moved freely. I put it all back together and it runs great!

Thanks for all the input! You helped me think through this problem to find the solution!

Back to top

IP Logged

Sheriff41

Junior Member

Offline

SuzukiSavage.com
Rocks!

Posts: 88
O'ahu, HI

Re: White spacer mod question
Reply #11 - 02/19/14 at 20:29:20

Well, after doing this easy mod and riding the bike for a few days, I have to say this is a great mod! My bike has never run as good! The smooth acceleration and lack of backfires is nice and are how Suzuki should have delivered the bike. The increase in torque and power are much more than I expected and really makes riding the S40 a blast!

Back to top

IP Logged