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2005 crf450r starting issue

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So I've done tons of research but its hard to find a specific answer, so basically this is my last attempt at help.

 

Im stationed in Japan and went home on leave about 2 years ago and bike wouldnt start. I just returned from leave again. And i proceded to do the following

 

-Cleaned carb up and down, there was not "gunk" but some blackish residue inside. Took care of that.

-Reshimmed valves, timing in correct.

-New plug

-went through fuel system cleaned and good. new fuel (premium)

-compression check but it only read 38 psi not upwards of 78 ( but could be due to auto decompreser not sure)

- i wire checked ecu and coil all was well

 

and after about 10 minutes of kicking and fuel on and off choke on and off, i got it to fire. but the idle was high as shit, turned it down, and in the process it had a hanging idle, 1/8 throttle braaps and it would stay super high up and take a few moments to crawl down to lower idle. ( hinting at carb issue?) whatever i finally got sort of a win so i called it a day. the next day i go to start it and mess with pilot jet and idle and it wont start again. i said screw it and 2 days later im back in japan, when i go home next id like to fix it so i can sell it. hard to market a broke bike. any ideas. possibly the valves are just shot period. previous owner was a retard and i never should have traded my trick 2005 250 for it... =/ live and learn

 

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What jetting are you runnin? I would try adjusting the fuel screw (on the bottom of the carb by the drain nut). Go all the way in, then out 1.5 turns. If it doesnt start turn it out another 1/4 turn and repeat. If you get to 5 turns or the screw falls out something else is going on.

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Def a carb issue if it was fine before it sat all that time. I'd read through the threads. Tons to learn about em on here

Edited by Diggla117

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^that and replace the vacuum seal and be sure you didn't put it back in upside down.. That itself could very well be your problem. That's and it needs a new pilot jet

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stop right there.. :) 
the bike will NEVER start with 38 psi. Around 70psi is the minimum to make an engine run. Your min spec is around 75+- if not mistaken (i think 02-03 was 68psi min). I have an 04 and an 08 and i know it's around there, just don't feel like digging out my manual.
You had the throttle held WFO when you did the test ? and a hard swift kick ? if so.. you got problems bub. Without the auto-decomp working, you would likely be able to stand on the kickstarter (literally) and not have it move down unless you weigh 175lb or more.

 

at some point if you think you have good compression, hold the plug against the engine and have someone kick it over .. ensure you have spark.

 

edit: well, obviously your gauge is junk or you were not kicking hard enough/holding throttle plate open cause it ran.  I would just buy a new pilot jet. the tiny hole down the MIDDLE of the jet is not easy to clean out, and often will corrode closed again.

Edited by MELK-MAN

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Thanks gentleman, sorry it took so long to write back, im still trying to get use to the forum, sometimes its shows someone wrote on a post, but now i have it figured out i just go to profile and content/follow or something like that. anyway okay thanks for the advice.i did the compression check with throttle wide open and kicked the hell out of it multiple times till it stopped climbing and reached 38 psi. but like i said i was reading that unless you do a leak down test my auto decompresser could be compensating therfore not fully going up.

 

i had my fuel screw to manual spec 1 7/8 turns out, but it very well could be the pilot jet being clogged. but when i took carb off and opened throttle body it squirted fuel ( forgive me if i sound un educated on the matter ) what was shooting fuel the pilot or main jet? either or if im not mistaken i didnt take jets out and clean them. just took carb apart and cleaned internal walls and what not.

 

so you guys think its the pilot jet and definetly a carb issue. and that would cause the hanging idle?

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Thanks gentleman, sorry it took so long to write back, im still trying to get use to the forum, sometimes its shows someone wrote on a post, but now i have it figured out i just go to profile and content/follow or something like that. anyway okay thanks for the advice.i did the compression check with throttle wide open and kicked the hell out of it multiple times till it stopped climbing and reached 38 psi. but like i said i was reading that unless you do a leak down test my auto decompresser could be compensating therfore not fully going up.

 

i had my fuel screw to manual spec 1 7/8 turns out, but it very well could be the pilot jet being clogged. but when i took carb off and opened throttle body it squirted fuel ( forgive me if i sound un educated on the matter ) what was shooting fuel the pilot or main jet? either or if im not mistaken i didnt take jets out and clean them. just took carb apart and cleaned internal walls and what not.

 

so you guys think its the pilot jet and definetly a carb issue. and that would cause the hanging idle?

 

 

Ok, you need to pull the jets and douche the shit out of them, or just replace them. The pilot jet is small enough to clog with dried fuel. The other issue is the ethanol drags water through the jets, which inturn will allow the jets to corrode when they sit. Double whammy.

 

Now, I wonder if you dont have a valve thats not seating correctlly, assuming its still not starting...that would cause low compression on an engine that was fine before it sat inactive. Its also why when you put the bike up, you should push the kicker around until its on compression. All the valves are closed, nothing gets in the cylinder. The valve seats stay clean etc...

 

The fuel screw and clogged pilot jet can be the hanging idle issue. Too lean, it'll hang, too rich, it'll hang.

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thanks guys ill try that, wont be able to do it for another year, but at least i know where to start

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