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Hello! I'm new to this forum so please forgive me if there's a topic already on this, but I'm having a lot of issues starting my bike. It literally will not kickstart, it bumps start just fine and it runs fantastic, it just won't kickstart. I had the valves checked (they were properly adjusted), timing checked, carb cleaned, replaced my spark plug, cleaned my air filter, I've tried just about everything and nothing has fixed my problems. The bike started great earlier this year, I had a piston kit put in it and it still started good but it slowly started to get worse, at first it would start sometimes, then it would only start when it was cold and refused to start when it was warm. Now it just will not kickstart no matter what I do. Most of the time when I kick it, it doesn't even sound like it wants to start. This issue has left me and my dad and all his friends scratching our heads confused. Hopefully someone here has an idea or ideas that can help! Thanks for your time

Welcome to the site !!

If you are positive the valve lash is correct , then you need to look into the carb more ..... did the bike sit for longer than 2 or 3 months with gas in it ??? , does the bike pop or backfire on deceleration (when riding and you let off the gas does it pop thru the muffler ?) , have you checked and or adjusted the fuel screw to see if it makes it worse or better ?? , (fuel screw is located at the bottom of the float bowl at the front of the carb *intake side* ) , The valves would be the most likely suspect , as that is where the symptoms start , is harder to start then progresses to running bad or stalling frequently , then not running at all when they finally close up , though it could also be a CDI or Stator issue , so you need to rule those out as well .......... When you checked the valves what were the readings ???

Also , Do you have a Owners or Service Manual ??? , this will help you perform the needed tests to rule out each item

My first guess would be valves , followed by carb ....... more detail in the symptoms and when/how they started would help as well , since there are many variables here that you have not explained ..........

Here is what you need to verify.....

The valve lash (what were the readings ??)

When the carb was cleaned , How was it cleaned ?? , and when you took off the bowl was there any green film inside the bowl bottom or anywhere inside the bowl or jet area ?? , were jets replaced or just cleaned and if so how were they cleaned ?? .... did you use carb cleaner spray without disassembling the carb ??

Did the bike sit as mentioned for more than 2 months with gas in the tank and more importantly in the carb ??

What did the plug look like when you pulled it ?? (white , gray , dark sooty ,tan)

Have you checked the spark ?? , if so was it bright blue or yellow/orange ?? , and was it consistent , or a intermittent spark ??

What is your starting procedure ?? , and was/is it the same before this issue and how did it start then ??

Hello I’m having the exact same issues I can’t kick start mine 2008 CRF250r it’s so aggravating it catches in gear runs perfect but just can’t kick start

Welcome to the site !!

What have you tried so far ???:

Checking/Adjusting valves ??

Bike sitting for a while ?? , Have you checked/Cleaned the carb ??

Info is needed besides bike wont kickstart , need history of bike if possible , did it just start doing this after purchasing recently ?? , do you know the maintenance or history of the bike ??

The more info you give the easier it is to diagnose , but usually not starting indicates valves either are zeroed out , or need adjusting (eventually they will need replaced if going out of adjustment) ... Or carb clogged due to bike sitting for long periods with Ethanol gas in it ... (3 months is a long period for Ethanol gas)

Welcome to the site !!

What have you tried so far ???:

Checking/Adjusting valves ??

Bike sitting for a while ?? , Have you checked/Cleaned the carb ??

Info is needed besides bike wont kickstart , need history of bike if possible , did it just start doing this after purchasing recently ?? , do you know the maintenance or history of the bike ??

The more info you give the easier it is to diagnose , but usually not starting indicates valves either are zeroed out , or need adjusting (eventually they will need replaced if going out of adjustment) ... Or carb clogged due to bike sitting for long periods with Ethanol gas in it ... (3 months is a long period for Ethanol gas)

Hello thanks for responding it has a new top end just done carb is perfect all clean brand new gas ethanol new #42 jet new spark plug which was expensive!! It runs like a champ when I catch it in gear it’s just kicking it won’t start up also when it’s hot it won’t start either I’m gonna take it to a local bike shop and have the valves looked at.

When you say "new top end" do you mean the piston ?? , or do you mean the piston and the valves were replaced as well ??

If the valves had been just adjusted , that means they are moving , once they start moving (in need of adjustment) then they will continue to move till there is no adjustment left due to shim size limitations , sometimes it is 20 or more hours in between adjustments needed , sometimes it is only a hour or so depending at which stage of wear they are .... basically the valve face wears , and as it wears the gap from the stem to the cam closes up , the shims take care of that space , once you get to the smallest shim , there is no adjustment left and the valves zero out , which means they will eventually hang open slightly , it can even get to the point where the valve face gets so thin , it snaps off and then you have a major issue with the valve head breaking off and going thru the piston or cylinder wall .... so those things need to be verified .... also (depending on who did the work) was the Timing Chain replaced ?? , has the timing been checked ??

Does it pop/backfire thru the muffler when you let off the gas while riding ???

What is your Main Jet size ?? , and what is your elevation ?? , did you check the adjustment of the Fuel Screw ?? , it should be around 1-7/8 turns out from lightly seated , then go from there in/out to get the highest idle ...

Here is the Jetting Specs , check your elevation and make sure yours is adjusted and set up like the chart


I am guessing you have had the carb off , if so how was the Hot Start working ?? , if the Hot Start plunger is stuck it can cause issues , the lever should work freely and snap back when used ...

Also , is it real easy to kick over or really hard (to push on the kickstarter) , as it could be possible the Decompressor is stuck , that might make it harder to kickstart , but it would push start fine .... Has anyone done a Compression or Leak Down Test on it ??

If you are sure it is jetted correctly , then my first guess would be valves are out of adjustment

If you have some mechanical skills , I can post pictures from the Service Manual to guide you thru checking the timing , valve adjustment , etc. ...