Cr500 dirt bike problems?

Question

i have a 89 cr500 with new wiseco 40 over piston , reeds,carb, i go to start bike kick it around 8 time then it back fire throw muffler if i rock the bike in gear about 15 times and kick it over it will start in about 6 kicks. what could be the problem? need bigger jetts? floats? all parts are new and cant figher it out please help

Answer 1

Will it start with choke?

Why would you need to bore a 500?

Answer 2

Been a long time from I had one,I would agree with guy above.

Answer 3

Well rocking the bike is doing nothing....First thing I would do is get a new plug..

Most of the time depending on what all was changed...40 over would hardly be anything..but enough to re-jet?? it might...

You need to warm the bike...Take a run down the road..on the way back say" 3rd gear half throttle hit the kill switch until the bike stops...Its called chopping the plug....

pull the spark plug...look at it....If its whitesh...need to go bigger on main jet....If its black and oily...Need to go smaller on the main jet......If its tan to dark tan...just right, dont do anything....

Turn your air s***w in until lightly seeded...Turn out 2 turns....Should be close to right.....If you have to go to say 3 turns then you need a bigger pilot jet...or the next size needle..

Hope this helps......Good luck

Answer 4

Rough necks right on the money.

How long has it been since the bike has had a set of reeds put in it?

New Plug?

Back Fire= Raw gas in the exhaust, Flooded, not firing strong, Then when it does try and fire it ignites the unburned fuel but the motor. I would Replace the plug do the plug test If the reeds have not been replaced do it this really helps out with performance. Good luck