First off let me say I have already done a complete rebuild on the carb and had a very seasoned driver drive the kart after doing the re build and the needles are adjusted correctly. But after 3-4 laps at the end of the straight the engines stats to bog and almost sound like it’s flooded and doesn’t make power and according to the mychron drops from 13,600 to less that 8 almost instantly but when going through the corner clears up and picks up halfway down the straight and then does it again! Changed plug tried both hotter and colder plug and still does the same thing and looking at the plug doesn’t look to be fat or even lean for that matter. So I’m am thinking either a coil or TCI possibly? Has anyone had this problem before?
KT100 bogging as it gets warm
- Thread starter F1F21
- Start date
It’s a fresh build
2 on the low and right around 3/8’s on the low. Pulse tube and all other fuel lines on the kart are all brand now and as far as the kart being tight not even close I can’t stand a tight kart if anything set up is way too free lol
Chris Cooper
Member
Does the engine do the same each session on the track ? I’ll through this out there …. If you have a tank that pulls fuel from the top, Check your tank fuel lines and vent - especially if you’re using a plastic tank that pulls fuel from the top. If that is the type tank, make sure you replace / check the pick up fuel line. I cannot tell you how long I chased this type of problem… 
Ya I was half asleep. 2 low and 3/8 high lol
Yes it’s the special line that the builder put on it. I forget the name of it
I’m running an aluminum tank that has the pick up on the bottom but I did make sure there was nothing restricting the vent tube and replaced the pet cock and vent fitting and all hoses just to be sureDoes the engine do the same each session on the track ? I’ll through this out there …. If you have a tank that pulls fuel from the top, Check your tank fuel lines and vent - especially if you’re using a plastic tank that pulls fuel from the top. If that is the type tank, make sure you replace / check the pick up fuel line. I cannot tell you how long I chased this type of problem…
I haven’t had the pop off checked yet. But I’ve got a buddy who has a gage and will check that next.
sundog
Member
Do you have the oem screen in the carb? They get clogged very quickly. Most run an aftermarket screen with an open mesh. If the pop off and arm height are right then 3/8" could be too rich, every carb is a little different. Can you tell when the engine's 4 stroking? I'm sure there's a utube that will teach.
I don’t this it’s 4 cycling honestly. It’s hard to describe the actual action other than he’s just bogs down and or surges. With the old engine I was able to get it to 4 cycle and that was my trigger to close the high speed a tick and this is different
sundog
Member
Well the arm height is too low or the pop off pressure is too high or both and when the fuel flow gets up to higher rpm it starts metering at the inlet needle? I would go through the carb and also check the plastic spacer and carb plate for air leaks. Fuel lines can leak air too if you don't tie them with wire.
phantomkartracer
Member
Double check that aluminum tank outlet. I had one once that must have had something floating around inside, blocking the outlet every once in a while. I replaced it with a plastic one.
If that isn't the problem. Try the coil. I had one that would rev to the correct RPM's sometimes then other times, acted like it was a governor.
Ring gap too tight?
Brian #89
Justin Greene
Member
What clutch are you using and where is it hitting at ?? Set it to hit at 10,400 to 10,600