Stall when stopping -updated and solved-

[TechGuy]

OK, My Kymco P250 had stalling problems last month when pulling away from an intersection.  I replaced the spark plug with an Iridium plug and I replaced the spark plug cable.  While I had the tupper off I also added sliders, cleaned the clutch pads (scuffed with a green scrubby), cleaned the old clutch pad dust out of the clutch bell and checked all the bits there.

Now, when I roll up to a stop sign or light, the engine seems to bog until the clutch shoes release for a true idle.  If I stop and the clutch shoes drag, the engine wants to stall.

It doesn't happen all of the time... but is worse (or seems that way) when 2-up

This is a carb'd bike

Any suggestions?

[Shaka]

Sounds like you need to pull the cvt cover and check everything again!  If the clutch is truly sticking engaged, you either have a broken spring or they are too weak.  Is the idle set too high?  It could also be your mix screw needs to be adjusted for more fuel.  The engine will idle high, then only sometimes drop down to normal when it is starved for fuel.

[TechGuy]

The idle seems fine or slightly low.  It's not racing or anything like that. I was wondering if the new sliders stay out longer and transmit more to the belt/clutch which keeps the bike "in gear" longer when rolling towards a stop. The clutch pads look fine.

[Shaka]

I have not experienced any prolonged engagement with the sliders, nor have I heard of them causing that.  The clutch looks of from the outside.  Can you see the fly springs in the back?  Maybe try pulling on the pads and make sure there is not play.  You may have to take the clutch off of the torque driver to inspect the backside where the springs go.  The pivots the pads move on my be sticky and not fully returning.  You could take the fly springs off and move the pads on the pivots, make sure they aren't binding. 

[wordslinger]

..it may just be the camera angle, but do those pads look like they are wearing unevenly?

 

[TechGuy]

Well, a seat of the pants experience today told me that is has more to do with 2-up than anything else.  

Today, I  scooted
   my daughter to school,
   back to the house (quick clothes change, it wasn't PJ Day today, it's tomorrow)
   back to school (1 mile each way)
   to Harbor Freight ( 5 miles)
   to work (~10 miles)

I have made NO carb adjustments (ever on this scoot)  

When we are is sitting on the rider/pillion, it will not idle.  When she climbs down, it will idle fine but maybe a little slow.

Ideas?

[wordslinger]

..could it be that there is a vacuum tube or your fuel line...or something?? being pinched with the extra added weight of a rider?

[TechGuy]

I will look into that... next week.  I am riding 300+ miles to a rally tomorrow.

[wordslinger]

...cool...RIDE SAFE!!!


peace

[TechGuy]

Question... is the spark plug supposed to have the round terminal cap no it?  The one that was in the scoot when I got it, and both replacement plugs do not have them either.

[zombie]

The spark plug will not have the little nipple on the end. Some applications need it, but the Kymco boots do not use them The boot is made to grab the threaded post on the plug. Another Maybe for the idle issue would be the throttle cable itself. Mine has moved, and caught on one of the retainer clips. Every time I hit a dip in the road or a sharp bump (moving the rear shocks) the rpm,s would jump because the throttle cable was being pulled in the opposite direction. Also the clutch springs will lose their tension over time from the heat generated inside the housing. They may look ok, but they may be at the end of their service life. I tend to believe your trouble is elsewhere tho.

[TechGuy]

I doubt it's the clutch. After replacing the spark plug with an Iridum, replacing the spark plug cable with new 7mm cable from NAPA, adding the sliders, scuffing the clutch pads and bell, and re-installing the windscreen; the bike is faster to accelerate, and climbs to 80 indicated with ZERO struggling.

I just idles and stalls when riding 2-up and very occasionally when 1-up.  It's like the carb doesn't like the tail down lower.  Or a hose is pinched ...  or/// I don't know.  I wish I were a better mechanic but I have been being a better dad than that.

[zombie]

You are on the right track w/ the 2 up. try to replicate it w/ the plastic off. Since you replaced the plug wire your boot may be different. If you look into it you should see a tube w/ a wire spring inside to grab the threads on the plug. The second type takes the missing nipple. It looks like a cup or a bowl. If you have the wrong type THAT will affect the spark, and in turn affect the rpm's. Check the obvious first.

[TechGuy]

Do you think this might have been a small factor in my inability to idle? 

My NEW QUESTION:  Leo Vince or Factory Replacement Muffler?  ... and why?  Just looking for confirmation of my suspicions/feelings.
 

[wordslinger]

..A LV muffler will require carburetor tuning after installation, but should ultimately increase performance..factory replacement should be plug-n-play...

..your pic didnt make it thru...

peace