Motorcycle jerking??

[Schneller]

Do some measuring. Follow manufacturer's recommendations in how long a certain number of links should be, maximum. Do this in different places along the chain. This will give you a definite answer if chain is stretched or not.

https://www.google.ca/search?q=how+...lBcuiqAaJoYGIAw&ved=0CEcQ7Ak&biw=1024&bih=672

a quick method is to pull the chain away from the rear sprocket and notice how far it will pull away.

 

[Brian P]

100% not the chain this is a brand new bike with messed up fueling from modifying it.

At 700 miles (?) km (?) it is almost inconceivable that the chain has already been ruined unless there is something the original poster is not telling us.

Do make sure the chain is not overtightened; seen a few that came overtightened from the original dealer.

But given that exhaust and intake modifications have been done without rejetting and the owner is reporting the bike running hot ... my money is on "lean surge" caused by carburetion that is now too lean, and given the road speed that is being reported, it is most likely the needle that needs to be shimmed up a little.

It is not "carb sync" ... there is nothing to synchronize a single carburetor with on a single cylinder engine ...

 

[Schneller]

At 700 miles (?) km (?) it is almost inconceivable that the chain has already been ruined unless there is something the original poster is not telling us.

Do make sure the chain is not overtightened; seen a few that came overtightened from the original dealer.

But given that exhaust and intake modifications have been done without rejetting and the owner is reporting the bike running hot ... my money is on "lean surge" caused by carburetion that is now too lean, and given the road speed that is being reported, it is most likely the needle that needs to be shimmed up a little.

It is not "carb sync" ... there is nothing to synchronize a single carburetor with on a single cylinder engine ...

Ah, I missed the 700m/km factoid!

 

[CafeRay]

I believe it was you who said you changed your exhaust and/or filter without rejetting. And now it's running hot, and it's surging at cruising. Both symptoms of lean fuel mixture.

Rejet before you bugger your engine

Do what he says.