atc 110 backpressure?

[PitboyJohn]

hey,im havin a hard time firin up my 110.i rebuilt the top end pretty much,fresh piston rings cylinder,valves were good.i made the bike out of 2 but only had 1 exhaust system and it was a redneck custom.(no cannister,just a header with a tiny tiller motor muffler welded on,basically straight pipe)when i pull it over it feels like theres no compression cause it pulls so easy.its my first 110 so i dont know if they pull real easy or if its a lack of backpresure.i know the timings right cause i followed the manual exactly.if its the exaust,is that a discontinued part.i have another 110 exhaust system but its got alot of rust holes and is too thin too weld up

my brothers birthdays coming up and i want to give it to him but want to get it running first.any tips would be great,thanks

[SWIGIN]

id get an aftermarket pipe. dennis kirk sells them and ebay has used ones but you are corect....back presure is a big thing on these little bikes

[Erics350x]

did you check your ring gap and piston clearance ?did you make sure the ring gaps where not close to each other? it should have good compression even if the exhaust was off the bike . how many hours do you have on the new rings ? maybe the havent seated yet..

[PowerTech]

it sould run with a lawn mower muffler fine.

test the compresion with a gauge if thats what it feels like.

[PitboyJohn]

the piston clearance is to spec.i got the piston and rings from the same company that bored the cylinder.the ring gaps are apart,i forget if its 180 degrees or 90 apart but i followed the haynes manual step by step.new base gasket,head gasket,head torqued down to spec.i've rebuilt alot of 4 stroke top ends but thye were all 185cc and up so you could feel the compression.i haven't started the bike since i rebuilt it so the rings arent set,getting good spark thou(correct timing) and its getting fuel. someone told me the 110's need backpressure to run cause i've ran bikes b 4 with no muffler.would the cylinder coming out the front instead of more verticle have an effect with the backpressure?

[PowerTech]

i have seen a 110 run just fine with a open cobra pipe.

try stuffing a banana up it pipe and see if it runs. just kidding.

i dont know why it dont star, you try to see if it will fire on a shot of starting fluid?

how about doing a compresion test?

[atctim]

just for your knowledge - 110's do not have near the compression (pull start kick-back) a 185cc. The pull start on my 110's pulls over really really easily. As easy as a 90 or prolly even just about as easy as a 70.

[Erics350x]

my yfm225 was really low on compression when i rebuilt it untill i ran it for awhile

[PitboyJohn]

thanks for the input guys,im gonna play with it tomorrow.quick start and take the pull start off and make it electric start with the cordless drill,that should get her fired up.

[bigreddaddy]

thanks for the input guys,im gonna play with it tomorrow.quick start and take the pull start off and make it electric start with the cordless drill,that should get her fired up.


I'd like to see a pic of that. I've never done it before. Nice lookin' Pit Bull by the way.

My Olde English Bulldogge site (haven't updated it in a while, lots of pics).

http://www.bayoubulldogges.com

[PitboyJohn]

ill be sure to take some pics when i do it,your dogs real nice man.same colors as mine.i had an olde english/valley bulldogge when i was a kid,they're powerhouses!!

[Erics350x]

just have someone pull you to start it.

[Erics350x]

as for the drill trick , i tried it when i was a kid ... not the best idea . think about what the drill will do when it starts, a hell breaks loose..lol

[PitboyJohn]

i have a 3/8 socket extention i use with my cordless,it can get bad and twist the drill out of your hand or bust your wrist but i've done it many times firin up crap bikes .u just gotta be quick to pull it off when the engine fires.it beats pulling your arm half off.