Engine skip or "Bucks"

[TQuentin1]

Back to closer to the beginning of this thread. Have you cleaned the IAC to see if that fixes the prob? If so, then replacing it should be on your ToDo list. Cleaning will only prove that is the problem. Redoing the venting like Jeff suggested and replacing the IAC should fix the problem for the long haul. But only if cleaning makes a difference right away.

Cheers,
TQ

 

[Lobo1]

Back to closer to the beginning of this thread. Have you cleaned the IAC to see if that fixes the prob? If so, then replacing it should be on your ToDo list. Cleaning will only prove that is the problem. Redoing the venting like Jeff suggested and replacing the IAC should fix the problem for the long haul. But only if cleaning makes a difference right away.

Cheers,
TQ

I haven't cleaned it yet but that is definitely on my list for this weekend. I am going to check for a vacuum leak at the intake since it was removed when they changed out the front head ( broken exhaust stud that I inherited from the previous owner. Head damaged by what looked like someone trying to weld a bolt or something to the stud that was broken off flush with the threaded bolt hole). If that isn't the problem I am going to check the fuel injector wires for chafing / cracked insulation / broken wire. I am DEFINITELY going to clean the IAC and quite possibly go ahead and revent it. Going to enjoy getting a little more intimate with the old girl.

 

[Jeff Klarich]

If that isn't the problem I am going to check the fuel injector wires for chafing / cracked insulation / broken wire.

A visual inspection is good but I would suggest you start it and wiggle the injector wires too. If it's a wire issue you should be able to detect it.
Another way you can check the wires is with a test light. With power to the injectors wiggle the wires and see if the test light comes on and off.

 

[Lobo1]

Well. One hour and 40 minutes I get off work and can get in my shop to find and fix the problem with my scooter. I am going to do a lot more regardless because there have been a ton of great suggestions that you fine folks have mentioned since I started this thread and l thank you all for the help. I am going to do em all just as a preventive measure. I will update later this evening.

Good news. I found the root cause of the problem. I did several things and I was going to test ride it after each one. Low and behold, I checked the TPS (Throttle Position Sensor) first. That was the easiest one to get to so it only made good sense to do that first. Took it off and owmed it out with my digital VOM. As I turned the pot slowly while watching the resistance readout, I noticed every time I got to a certain spot the readout would read "OL" which means the pot coil was open. A dead spot. Went to the local dealer, bought a new one for 37 bucks, installed it, rode it 36 miles, ran like new.
Came home, checked the fuel injector wires, cleaned the IAC,checked for air / vacuum leak while the engine was still hot. Bought the hose screen filter and "Tee" fitting to reroute the Crankcase vent to the atmosphere underneath the bike. That job will be on tomorrow's list.

 

[Jeff Klarich]

Good find, thanks for the update. You won't be disappointed venting, carbon buildup on the top of the pistons will be none existent and no more oily carbone mess building up in your IAC port.

 

[Lobo1]

Good find, thanks for the update. You won't be disappointed venting, carbon buildup on the top of the pistons will be none existent and no more oily carbone mess building up in your IAC port.

Yeah I agree 100%. It looked awful. Took a while to get it clean but looks new now. The venting will be my afternoon project and then a nice ride up in the N Ga mountains. Ahhhhh life is good.

 

[Harttoo]

Glad to hear You found the problem.

 

[Lobo1]

Yeah me too. It was very annoying and often times embarrassing. I am also glad and thankful for all the help, suggestions and posts from the members here. I haven't been a member long but I plainly see this is a great bunch of folks here. I have already performed many of the suggestions in this thread and will be doing others today. Buying a used bike, I want to make it All right.