atc 90 with a 110 carburetor question need help!!

[flowmasterman]

hey all, I have a 78 ATC 90 with a 110 carb on it, i have read on here this is a easy bolt on upgrade, question is, can you just bolt this carb up to a stock atc 90 with no other mods? Wouldn't the jets be different in the 110 carb? Reason being is the 90 doesnt seem to have much power, i know it doesnt already, but I can tell it sluggish, and it keeps fouling the plugs out like it gettin to much gas and causing it to foul out. It idles fine after warmed up, takes gas in all throttle positions but is sluggish, and when at idle in neutral can give it wide open throttle but doesnt take all gas it sounds like it flooding, and lastly, when I try to adjust the air screw, from all way in to all way out, doesnt make a difference at all? Any ideas anyone?

[shortline10]

A 90 carb is 16mm and the 110 is 18mm so its a little upgrade . Bolt it up and do a plug chop . In most cases the 110 to 90 carb swap should be fine as is .

[flowmasterman]

what do you mean when say do a plug chop? and what about the air screw not affecting it any when I turn it in and out? thanks!

[flowmasterman]

anyone else out there able to help on this?

[flowmasterman]

noone? like said trike is "rideable" as is, but I can tell something not right, doesnt seem to really go as it should, reeeallllly slow acceleration, and fouls the plugs, thats why i think something to do with carburetor? it idles, it starts on 1 pull with a good plug. but it fouls them pretty fast...so i thought maybe the bigger carb had bigger jets,, i dunno? like said it will take gas fine at idle or in gear driving it...but when in neutral at an idle and wide open throttle it, it never gets to the point where I am like whoa i better let off the gas,, it will get up there in there in RPM's but then sputters a bit and doesnt go any higher?

[Xpress]

You need to give people time to respond. Not everyone constantly browses the forum.

[shortline10]

Adjust or replace your points and it sounds like it's time to rebuild the carb if the air screw is doing nothing . You also should do a compression thest to see if its time to rebuild the top end .

[flowmasterman]

"gotcha" xpress...shortline, how much compression should I have when doing the test? like I said it starts in 1 pull.."but" it does smoke some..I remember when I had a Kawasaki 80 dirt bike that was 2 stroke it wouldnt start unless pull start behind another bike cuz rings were shot, and on a 4 stroke 90 it has seperate rings for compression and for oil control? on the carb u say to "rebuild" there nothing to rebuild in there? I cleaned the main and slow jets, made sure they were clear, soaked the carb, it didnt run when I got the trike, now it does, what else could it be u think? clean carb again, i put in line filters on it too..what ya think?