Rattler engine problem again
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- MacJac
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Rattler engine problem again
I never had this happen, but sitting at idle at stop signs/lights, then accelerating, killed the engine 3 times on me yesterday. 2 other times all I had to do was let off the throttle, and dead.
I've already had the scooter in for a carb clean, the tank is filled only 3/4 so it's not a vapor lock issue, I've adjusted the idle screw, and I'm at wit's end now. Does anyone know what the problem could be?
I've already had the scooter in for a carb clean, the tank is filled only 3/4 so it's not a vapor lock issue, I've adjusted the idle screw, and I'm at wit's end now. Does anyone know what the problem could be?
- Ray Knobs
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- pattyman5000
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- MacJac
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The weather has been snow-filled here in Chicagoland, so I've sort of thrown the problem on the backburner for a while. I do start up the Rat every month, but never looked into what Ray said about the other knob for fuel/air mixture. Since it is very cold in my unattached garage, I have to kick-start it to get it going, and it usually starts up on the second try. One it's warmed up and I shut it down, it does start right up again with the battery.
I don't have the manual around me right now, but I should look into the air/fuel adjustment soon, since Spring will be here before we know it.
Any help here Ray of where the air/fuel adjustment is, that would be great.
I'll look into it also. And thanks for the reminder!!!
I don't have the manual around me right now, but I should look into the air/fuel adjustment soon, since Spring will be here before we know it.
Any help here Ray of where the air/fuel adjustment is, that would be great.
I'll look into it also. And thanks for the reminder!!!
- Ray Knobs
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- MotoSteve
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I had the same problem. On a cold start, the bike would bog down and stall at stoplights. This was with the Pima pipe and the rest stock.
As the air gets colder, it gets denser and your mixture gets leaner. Needs more fuel.
My mechanic installed a larger main jet and adjusted the fuel/air mix screw. Problem solved. It no longer stalls.
As the air gets colder, it gets denser and your mixture gets leaner. Needs more fuel.
My mechanic installed a larger main jet and adjusted the fuel/air mix screw. Problem solved. It no longer stalls.
KTM 950sm, "Ducati Desmo WSB" Rattler 110.
- MacJac
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Thanks for the advice Ray. I couldn't wait for spring. It was 55 degrees around Chicago today. I took the seat off and adjusted the fuel/air screw 1/8 turn, popped the seat back in with screws sitting on my workbench, hopped on and held a steady throttle at 35 mph, and at the end of my block when I slowed to idle the engine cut. This time I was able to play with the throttle until it caught, so I went back to my garage, repeated the process again, another 1/8 turn, and this time the ride was fine.
- Ray Knobs
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- nissanman
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For those of us in areas with climates that change, a slightly modified bike will require periodic air/fuel adjustments. Just part of the deal. Do what I did and drill a hole over the top of the adjustment screw (just big enough to fit the screwdriver through). Now adjusting the carb only requires opening the pet carrier and not the full removal of the dang thing. Saves lots of hassle and time 

EZPZ #65
- Ray Knobs
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- nissanman
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SIX bolts off and on, then test ride, then SIX bolts off and on repeat as necessary. Don't forget the screw that attaches the fender liner to the bottom of the seat bucket too. There's already 3 small holes in the bottom as drain holes, now I have a 4th that's dual purpose. I won't ride the bike with an un-bolted seat it just doesn't seem safe to me. ATSATT (all the seat all the time). If I'm running ice and beer around I'll bust out the duct tape for the occasion 

EZPZ #65
- MacJac
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Great idea about drilling a hole above the adjustment screw. Saves a ton of time not having to take those bolts out. I only drove it with the seat bolts out up and down my block. Since I've caught a little air going over some questionable areas of railroad track before, I couldn't imagine the seat being loose after doing that. As for beer hauling, just say hello to a Hefty lawn bag cut down to fit.
- Ray Knobs
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