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Discussion Starter · #1 ·
Engine mods: Power commander v with autotune, uni air filter without box, dasa exhaust.

Problem: Bike will not start when hot. I can ride the bike for awhile (I've never rode for more than 30 minutes constantly), but the second I kill it or it decides to just die, I can't get it started without letting it cool for a few minutes. Bike just cranks. Normally the bike is hot enough the fan has kicked on...a few times it wouldn't start slightly cooler than whatever temp the fan kicks on. If I can keep the bike running, it runs great. Also has a weird idle issue. First start the bike up and it'll idle at 2500rpm, then after about a minute and a half or so it'll drop to as low as 1600rpm, then might go up to 2200rpm or stay around the 1800rpm--does this no matter how I adjust idle.

Troubleshooting: I had prior issues with starting when it was warm and the culprit was too loose on the exhaust valve spec. Both intake and exhaust have been set within spec. Let the bike idle until it shuts itself off (revved a couple times here and there). It'll idle for 10 to 15 minutes and then shut off. Go to start and it just cranks. Hooked up a timing light immediately after and there is inconsistent/no spark. I say inconsistent because sometimes it does fire, just not as it should (ie fires on 1 stroke, but not the next 2 etc).

Guess: If I were to guess, I'd say a sensor or something is getting warm and causing a spark issue when the bike reaches temp. As for the idle, maybe it has to do with the programmer because I haven't quite figured it out, kinda just left the program in it from the previous owner.

LONG STORY, I know, but I'd really appreciate any input/help before I start taking CO2 to sensor to cool them down to see if that is my problem. Thanks for reading, or not reading :)
 

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Start with the basics.

First disconnect the PCV and see if it still does it. Second check for any Diagnostic trouble codes. 3rd check for proper fuel pressure when acting up. The intermittent spart leads me towards the CKP sensor.
 

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test your fuel pressure I had a fuel pump go out the exact way your describing. I read people talking about intermittent spark while testing but still end up having a fuel issue
 

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Discussion Starter · #4 ·
UPDATE:

So problem is still there. Let the bike heat up to the point it was hard to start...ie just cranking away. Then used CO2 to cool the cdi module down. It's been awhile since I did that. Seemed to run if I kept the cdi cool.

This past weekend, I started the bike after it was sitting for a few weeks. Fired right up, so I shut it off. Got the heat gun out and heated up the cdi. Once the outside temp reached around 200 degrees or so, tried to start the bike and it would not start. Let it cool off, and start right up.

Anyone ever have a cdi go bad? Evidence definitely points to a bad cdi.
 
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