The only way removing the vent tube could make any difference is if it was pinched to start with. It's just a vent tube to the float bowl. It really doesn't matter if it's vented to the air cleaner, or the atmosphere. It's not like it's a crankcase vent, or something like that going into the air cleaner.I just find it strange that on some if you pull the vent tube out of the air intake they run better, and some have no change. Is there such a difference from Carb to Carb?
Good job. Did your bike run as bad out of the box as most peoples?Snap On has a real nice drill set for jetting #YA246A .If you dont have access to a dealer you can buy online. My Skyhawk 66 works well with #66 and clip second from bottom. Pulls hills great with slight fourstoking WOT without load.Im still using break in mix.Gonna wait for anymore tuning till after break in is over
I wouldn't go any futher till you finish break in and start the regular pre mix. What spark plug are you using?I notice after riding for about 10mins it starts to bog down. Is this a air issue, I've drilled the jet to #64 and have clip at the middle position. My spark plug is black but it's not gunking up, it's slightly wet but nothing serious. I've been running about a week now still breaking in.
These motors seem to be kind of sensitive spark plugs. It might be worth $2 to try a NGK BP6HSAutolite 4093 I believe not sure about the numbers. I did have it drilled to 66, but after I notice it bogging I went to the max it said here. I think it's 4stroking too, I've ran the clip at the second highest setting but it didn't seem to have power and was still 4 stroking, or at least I think it is.