Freshman Rider
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Post by userix on Jul 3, 2014 18:58:08 GMT -5
I am having a moderate loss of low-end torque/acceleration on my scooter. I recently replaced a new A7TC plug to fix a previous stuttering problem. The scooter pulls very well off the line when I ride it from a cold start. But after riding for 30 minutes, I lose a lot of low-end acceleration off the line (0-25 mph), but the mid and top-end acceleration is still very good (30mph and up). There are no backfires or popping on accel or decel and there are no leaks around the head gasket, the spark plug, valve cover and carb mounting flange.
Other than the loss of low-end torque/acceleration, the scooter runs fine. The jetting hasn't been messed with since it was running well last time. The CVT clutch and variator weights have not been altered/changed since it was last running fine. I inspected the belt and it looks to be in good condition. And from the video I posted above, it doesn't sound like the belt is slipping either.
The acceleration is so bad that I have problems pulling away from cars at a traffic light. I usually can accelerate much faster and not hold up traffic before.
What could be the cause of loss of low-end torque if nothing else has changed on the scooter except for a new spark plug of the same type?
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Post by alleyoop on Jul 3, 2014 19:17:29 GMT -5
First adjust the Valves, both to .004 inchs that is probably why it is more doggish after it gets hot.
Then it needs a little carb fuel mixture tuning it has a little lag on it when you open the throttle.
Alleyoop
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Freshman Rider
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Post by userix on Jul 4, 2014 13:04:50 GMT -5
First adjust the Valves, both to .004 inchs that is probably why it is more doggish after it gets hot. Then it needs a little carb fuel mixture tuning it has a little lag on it when you open the throttle. Alleyoop Thanks for the reply. Is it more doggish because the valves are too tight or too loose? I'll give that a try next |
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New Rider
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All throttle, no bottle.....
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Post by Noneshere on Jul 4, 2014 15:29:54 GMT -5
Yep , alley. I just rebuilt a stock 150 and on the test drive with the owner on it, the engine went floppy once good and hot. Embarrassing as it was , the next day I found the valves a little to tight. The owners been by a few times just to say hello and has put 300 miles on it in it first week already.
These engines seem to like a little (late) play in the valves, especially on the exhaust side imo.
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..BAD TO THE BONE..
