[finster]

I have a 2009 CRF250R and have been battling a hard start issue forever. The bike sat for a year, put in fresh gas and twisted throttle a few times and started first kick. Ran great for short rides, Shut off and would not go again.

Aside from all the other 1000's I've read of posts my question is about the accelerator pump. If I twist the throttle with the airbox off I get a tiny amount of fuel from the accel pump. If I manually operate the pump lever behind the cover I get an awesome spray of fuel.
When it does run there is no bog on accel and responds well when you snap the throttle.

When it won't start it seems as if it's not getting fuel, I have the carb off now and going to try a 60 leakjet instead of the 70.
It has a 185 main and a 45 pilot jet, valves, timing and compression have been triple checked.

Is there any reason why when you roll the throttle there is only a dribble of fuel? Diaphram looks good. Seems as if the pump too slow and wondering if the leak jet has something to do with that.

[JimDirt]

Welcome to the site !!

What I would think is in the area you are thinking , but I would look at the actual passage in the bowl for the accelerator pump , and also look at the diaphragm itself , you can do a test with the carb off the bike , simply assemble it all (after the cleaning of the bowl) and fill the bowl thru the gas line (you do not have to fill it all the way , just enough to maybe half fill it to make sure the passage fills so the pump can suck the gas thru) and work the throttle and watch what the pump does , if it is not flowing after the cleaning , then I would look closely at the diaphragm , you could have possibly put it in upside down when you were initially cleaning

Also look at the linkage , the rod from the pump actuates off the linkage , make sure it is moving the rod fully .....

That is where I would start .....

[Nikonov_94]

I can confirm that it can be the diaphragm being put upside down... from my own very, very recent experience it happened to me this Monday, when I wanted to get to work, as I had been tinkering during the weekend. I was a bit distracted because I had spent more time than expected writing about this Spain investor visa https://tranio.com/articles/golden-visa-in-spain/ and ended up cleaning the pump with my head somewhere else, under an electric light, which led to me putting the diaphragm upside down and going to work by bus the next day instead of riding my bike there as I usually do