Spittin, sputtering and backfireing

[mcgroom]

Bought used 2002 Prosport in Aug. here in Ohio. Previous owner never used choke. 3 cracks on the throttle and fire it up. I felt like this was loading air cleaner up to much. Switched to new K & N air cleaner and partial choke at start. Engine idle increased considerably so backed the idle a bit. Started having trouble with starts and fouling plugs. Replaced plugs let the bike warm up for 20 mins or better and went to get full tank to store for the winter. Had trouble maintaining idle at lights and she would spit and sputter when I would get on her a bit. Got the bike back, let her run to let new fuel work through the system. I can't even hold an idle now for more than a minute before she shuts down.

Went through adjustment per Service Man. and the only difference I experience is increased idle speed when I turn idle screw clockwide a 1/4 to a 1/2 turn. Still won't stay running more than a minute or so.

Becoming very frustrated and suspect any number of things from dirty carb, main jet being to small with new air cleaner, electrical etc. Any advice would be helpfull.

Thanks

 

[Gas Man]

First off Welcome.

The reason we don't the choke/enricher is cause it does just that, fouls plugs. If you have to use it cause its really cold, then ok, but get it off ASAP.

First off I would ensure your plugs aren't fouled again. Then get it fired up. Get the bike and carb warm. Then time to adjust it.

You can use the below links and my little typed out version

S&S adjustments
http://www.bikernet.com/garage/PageViewer.asp?PageID=1081

S&S Carb Manual
http://www.sscycle.com/modules/instruction/uploads/51-1012.pdf


To adjust the carb... with the bike warm...
(in=clockwise/out=counter)

if your idle is low... turn it up a bit...

now spin in the accel pump screw till it seats. Now spin it out 1.5 turns

now spin in your fuel/air mix screw till the motor sounds like it wants to die

now spin it back out counting 1/4 turns. Do it slowly to give the motor/carb time to adjust. Do this till the motor sound like it wants to die on this end. Now you have counted those turns and you have say 2.5 turns. Spin it back in 1.25 turns. Or middle to almost dead on each end.

Now adjust your idle to 1,000 rpms on the tach.

Now with a few quick stabs at the throttle see if the rpms come up fast like you would think or if it kinda hesitates then takes off. If it does hesitate then spin the accel pump out another 1/4 turn and repeat till you get what sounds good.

If that don't fix the sneeze... you can spin out the accel pump a bit more... but anything over 2.5 turns means you need a larger intermiediate jet.

 

[mcgroom]

Thanks for the quick response and info. We are sunny today so I am working on excuses to get out of work, make the adjustments and road test her for a bit.

 

[pink chopper]

You might check your intakes for leaks also...when the bike is running spray either WD-40 or carb cleaner directly on the place where the intake meets the head and see if the idle changes...if it does, it's an intake leak.

 

[mcgroom]

HUGE help....as you suspected, replaced plugs with spare set due to excessive fouling....printed up S&S listings you provided an placed in my tech manual for future reference....adjusted just as you mentioned short of having a tach and as you suspected, my problem is resolved.

Very cool to know there are others out there who are willing to help.

Thanks again.

 

[Skynut]

Sweet, a happy ending.

Right on Gas Man

 

[Raywood]

HUGE help....as you suspected, replaced plugs with spare set due to excessive fouling....printed up S&S listings you provided an placed in my tech manual for future reference....adjusted just as you mentioned short of having a tach and as you suspected, my problem is resolved.

Very cool to know there are others out there who are willing to help.

Thanks again.

Glad you got fixed up. Those S&S carbs are real easy to adjust once you overcome the fear of touching it.
Remember now, don't use the enricher after the motor starts and then only on real cold days when you need it!

 

[LamboV12]

Especially true on the 107 - I had to remove the lever all together because even when it was in the "down" position, it placed slight pressure on the plunger causeing it to run rich. It was a nightmare until I figured it out.

 

[Gas Man]

Bought used 2002 Prosport in Aug. here in Ohio. Previous owner never used choke. 3 cracks on the throttle and fire it up. I felt like this was loading air cleaner up to much. Switched to new K & N air cleaner and partial choke at start. Engine idle increased considerably so backed the idle a bit. Started having trouble with starts and fouling plugs. Replaced plugs let the bike warm up for 20 mins or better and went to get full tank to store for the winter. Had trouble maintaining idle at lights and she would spit and sputter when I would get on her a bit. Got the bike back, let her run to let new fuel work through the system. I can't even hold an idle now for more than a minute before she shuts down.

Went through adjustment per Service Man. and the only difference I experience is increased idle speed when I turn idle screw clockwide a 1/4 to a 1/2 turn. Still won't stay running more than a minute or so.

Becoming very frustrated and suspect any number of things from dirty carb, main jet being to small with new air cleaner, electrical etc. Any advice would be helpfull.

Thanks

A couple of things I want to add. The idle is suppose to come up with the choke/enricher. So don't adjust the idle screw back down as when you take the choke off, the idle will be too low for the motor to stay running, as you said you had a problem with.

You shouldn't let the bike idle for 20mins. No reason. I usually only let mine run long enough to helmet and gear up. In the real cold or if I have the time, long enough to feel some heat in the rocker boxes (top of the motor). Then GO TIME!

Further, your main jet don't kick in till about 2750-3000 rpms. Otherwise its all int jet. That is commonly the most common jet that needs changing sense 70%++ of your riding is done on that jet.

Just wanted to clarify a few things. Glad it worked out well for you.

Not sure where you are at in OH10 but I'm about 30 miles north of the border. Got the MC lift, and enough tools to get in trouble. The garage is always open for good people and some guys like Big House (member here).

 

[ahoffme]

Thanks for the fix, the spittin, sputtering, and backfireing was driving me nuts.