2009 Gas Gas 450fsr starting whoas, help!


sick 96 250

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Recently acquired a 2009 Gas Gas 450fsr fuel injected bike and I am having issues getting it to run properly. I can't say I really rode the bike before the issues at hand to really compare. I recently put a new fuel pump in it, new injector, spark plug and new radiators. Initial fire she started right up, I did a few heat cycles for the computer to relearn. I can fire it up, let it warm up, shut it down and it will always fire up afterwards. If however I take it up the road and back it will not start afterwards. I'm guessing I should check the valves next but it seems like the bike is flooding upon restarting after actually riding it a short distance. I know there are several sensors on this bike as well and curious if maybe a Temp Sensor or TPS would be a better start to go at. I can often re-fire it with throttle wide open which is procedure for a flooded bike. Its fuel injected and I find it odd that it's only after I actually ride it I have issues. Power is plentiful and engine braking is present which these bikes have quite a bit of.

I'm lost at this point as to why it won't fire after physically riding it. Any help?
 

RM_guy

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Hey bud! How have you been doing? I sure do miss those Paragon rides we use to have.

As far as the bike goes, first mistake...you bought a 4 stroke! =)You are probably on the right track about a sensor being bad. I'm not really a 4 stroke guy but I'd guess a temp sensor since it has issues after a short ride. It's probably getting a lot hotter than just letting is "warm up" and the computer thinks it's still cold and dumping more fuel in. I may be all wet but it sounds like you hit on all of the other thinks already.
 

sick 96 250

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Man, blast from the past! The Paragon days were a blast and def one heck of a time. Not to shabby riding out here in the Arizona desert though. I've been on and off 4t's but really considering getting ktm 300. I feel more at home working on 2T's and this FI stuff is just confusing. I still have my 99 RM250 from the Paragon days oddly enough and it still puts around! I checked the valves and they are sitting a tad tight from the numbers I could find online but as much as I want to like this bike I hate there is no info anywhere on it. Its nice to have a street legal dirt bike but I think I'm going to adjust the valves and see what happens then she's getting sold. Hope all is well man and hopefully you're still getting out with the rest of the Yanks!
 

RM_guy

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I didn't realize you were in AZ! Glad the riding is good. Lori and Dave are out in NM someplace doing a lot of dual sport riding. I've kinda lost touch with most of the crew but still ride at least once a year with Scooter. There is a place in Dunmore PA to ride and he cut most of the single track. Papakeith flew out to go to Unadilla one year with me. I got us some full pit passes and we had a good time. I saw him a few times at Southwick too but haven't done any riding with him. I bought a Beta 300RR in 2017 and absolutely love it. I actually comes with a clean tittle so I could put it on the road if I wanted. You should check them out. Good to hear from you!
 

sick 96 250

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Been out in AZ since 07. I think Paragon either had just shut down or was very close to doing so. I remember all the people you named and I think Mike and Jason were also present quite often. Def a good group out there!

I think I am going to shoot for KTM, Husqvarna, Beta, Gas Gas or Sherco 300 2t. My current 09 450fsr is a beautiful bike just I dont know much about fuel strokes FI systems and there really isn't a lot of direct info out there on the Gas Gas. I finally got the valve specs and it looks like my exhaust are a bit tight out-of range and intake valves are at the tightest spec allowed. Going to shim it tomorrow once the shims get here and hope thats it.
 

sick 96 250

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For anyone else that runs into an issue similar to this with a fuel injected bike, check your Temp Sensor. I was going through the process of testing and noticed it would read OL occasionally. I thought it was just me not using the multimeter correctly with the probes but ended up the temp sensor was on the way out. Replaced it with a cross reference sensor from Napa and its starting and running much better. The bad sensor was dumping way to much fuel once the bike was at operating temperature causing it to load up and then not start.
 

RM_guy

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...You are probably on the right track about a sensor being bad. I'm not really a 4 stroke guy but I'd guess a temp sensor since it has issues after a short ride. It's probably getting a lot hotter than just letting is "warm up" and the computer thinks it's still cold and dumping more fuel in...
Ha! Leave it to a 2 stroke guy to diagnose your problem!!!!!
 

sick 96 250

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I'll give him the credit, merry Christmas lol
 


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