ATC 110.. backfiring flames and bogs

[diffinking]

hi all ive just rebuilt my atc 110
now when i get it started its backfiring flames .when reving down
but when reving up if you push the throttle to fast it will bog ..if u push gradually its ok

the bike has just had a topend rebuild + carb rebuild+ i bought a dg racing pipe for it

any thoughts and carb stting would be helpfull

thnx ryan

[84honda200s]

sounds almost like timing or valves. what year 110 ?

[honda_atc200es]

your jetting might be off and the fuel mixture might be too rich, do the spark plug test

[kilabeez0]

too rich or too lean. could be either. do a plug test.

[diffinking]

its a 1985 last of the atc 110 ..dont think its timing as i had it done correctly
but could be the valves maybe needing set

[Vealmonkey]

usually when you change the pipe to a more free flowing exhaust or change the airfilter to a freer flowing filter, it has a tendency to lean out the carb not richen it up. You didn't mention if you installed bigger jets. If you used a normal carb rebuilding kit, more than likely it has stock size jets and they are probably slightly undersized or lean. First, did you make sure and intall all your gaskets on the intake including the o-ring between the carb and intake and also the insulator block in the proper spot? Are the mating surfaces of the intake nice and smooth and flush with the carb and the engine block? If there are any air gaps that could cause the back firing. Also, you would have to check when the thumb throttle is at rest, is the slide all the way down to the idle position? When you operate the throttle, does the slide come all the way open or bind up on it's way open? Did you start with the clip on your needle in the middle position? Do you have your idle and air\fuel mixture screws properly set? These things can make the trike bog when you open the throttle. There are so many little things that it can be a long process of elimination to find out what is wrong. Learning to set a carb can be a long process if you are not familiar with it. Please double check all your gaskets and o-rings first, cost is nothing also checking for air gaps at all of these joints also. Next would be check the throttle cable for sticking and making sure the slide is working correctly. Also, your carb is at least 20 years old. The slide and the inside of the carb wear with time and can allow air to be sucked in and basically the carb would be no good. Sometimes the carbs just can't be rebuilt anymore and you have to find a better carb to be rebuilt. Some of these parts are a crapshoot if they are anygood or not.
It might not be the carb at all, could be a bad cdi box, but you have to start looking somewhere and the carb and it's workings are a little easier to troubleshoot than a cdi box. About the best way I know of to troubleshoot the cdi box is to have a spare available and if both boxes cause the bike to act the same way, I would have to say than the cdi box is not the culprit. Welcome to the joy of working on something that is over 20 years old. Hope you find the problem. Keep smiling.

[vintagemotorsports]

sounds like your valve timing is off , put it on TDC and check your cam sprocket to see if your marks are dead on , I have seen this problem before , also make sure your valve gap is not too tight Mike

[diffinking]

thnx for the advice m8 .. yeah theres no air leaks ,+i started with the needle in the middle clip.. could possible need the mixture screw set will have a go