Jerkiness when slowing down

M

maxsideburn

Member
When I let off of the gas and the bike starts slowing down it gets really jerky. Almost like the motor is missing or something.

It accelerates just fine and pulls good, it idles pretty good, just starts kinda "jerking" when the bike is slowing down. Now obviously if I'm going to come to a stop I hold in the clutch lever, but I'm talking about just slowing down a little bit to take a turn or something, I barely slow down and it's like the engine doesn't like what's going on. It used to not do this.

Sometimes after riding for a while it also seems to idle a bit high when I disengage the clutch and coast to a stop. Instead of settling to a nice idle right away it seems to take a few seconds of higher rpms before it settles down.

Any thoughts?
 
Start checking for an air leak in the intake area. The carburetor to intake manifold is the most likely place but also take a look at the intake manifold gasket where it attaches to the cylinder. The kit supplied gaskets are notorious for failing if they were not sealed and tightened correctly.
This is assuming you have a Chinese 2 stroke engine. You didn't say.
Tom
 
Sorry to butt in on the thread but since i was having the same problem. Well today i was going over everything on my bike(it is a 66cc) i discovered the aluminum intake had cracked. So i was getting a air leak. its funny that a couple of hours later i got on my computer and saw that there was a reply. and low and behold , the reply was to check for a air leak at the manifold. Man, some of you guys rerally know whats up.
So maxsideburn that would be a good place to check.
And thanks 2door for the reply.
 
You're very welcome Rich. That's why wer're here.
There are other potential places to look for air leaks, actually they're vacuum leaks; the crankshaft seals that are located behind the right side primary gear, the small one on the crankshaft, and on the left side behind the magneto rotor, magnet. They are known to go bad in addition to the intake area.
When you replace that intake manifold look for one made of steel as opposed to the cast aluminum type. They're far less prone to cracking.
Good luck.
Tom
 
I have a new GT5-A, iwould hope the seals on the crank are not bad, but i dont think so. I have already replaced the head and bottom gasket , every stud and screw. it semed to run really good except for the chug,chug when slowing down.
Unfortunetly with the 40mm intake bolt spacing i could only find aluminum. Ill just have to not tighten so much. i think i was just in the crankem all down mood that day.
I was pondering the thought of a MM billit intake but with the motor at an angle the carb would not be level, but what if the base was shaved at an angle to bring the tube more level? hum.. but even 40mm wont be in stock for a week. Wait for parts , wait for parts....
 
You must log in or register to reply here.
Back
Top