Hello to everyone,
My question is,If the stock airbox is removed from the intake tube will that cause the atv to run bad.Can that cause a lean condition at top end and kill the atv.
The reason Im asking this is because my sons ds90 which is a 03 I think was running bad so I propped the rear tires up and gave it the rev to clear out the carb.The atv exaust pipe got hot and the bottom air box half melted a hole through it.I took the air box off and looped the oiler because I think the atv wasnt getting oil and thats what could have caused the atv to run badin the first place.I know Im kinda jumping around here but this is what I did.
1.atv running bad
2.propped up and reved to test carb
3.overheated atv and melted air box
4.let cool down and removed air box
5.restarted and noticed no smoke at exaust
6.removed carb and cleaned
7.looped oil injector
8.premixed at 27:1
9.started atv with a chinese air filter that has the same size rubber boot as the intake pipe which is 1 3/8
10. atv not running to good
11.fabed old air box bottom and installed back.
12. atv running good.
So with all that said my questions are just as long.
1.Doz the air box create a restriction on the carb that is matched up with the jetting so the atv runs good
2.can the oil Im running be the issue with the oiler "pennzoil marine"
3.Doz anyone know where to get a bottom air box half
I will stop here and see where this post goes
thanks from florida
be safe and take a kid riding

 

1) Yes, change the air flows/restriction you will effect the fuel/air ratios.
2) Oils are different. Some are made for injection, some are made to mix.
3) I'm guessing a dealer.
The hot pipe is interesting. It could be plugged.