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Discussion Starter #1
I was lucky enough to find a gently used '03 a couple of months ago that I scooped up quickly. I put it up on stands to do various mods to it but would start it every few days because the exhaust note is sweet (Ti Banzai-mount Satos). This week's project was the flapper mod and PAIR system removal. I used the block-off plates and cover from Kyle Racing and put things back together last night.

When I tried to fire the bike up it didn't want to start, so I gave it some throttle and it fired up; however, once I let it drop to idle it died. Starting it with the choke on kept the idle high enough that it would continue to run on its own, but when I blipped the throttle it would die again. I thought maybe I had a vacuum leak someplace but couldn't find anything obvious pertaining to the parts I had removed. After tinkering a bit I tried again with the same results, but decided to let the engine warm up this time. As it turns out once the temp comes up it idles and seems to run fine, but I'm paranoid now.

I did some reading and a few things stand out as possibilities - vacuum leak, TPS, FPR, PCIII, water/debris in fuel, etc. Before I tear the thing apart again though, I wanted to see if anybody had some more specific advice or similar experience I can learn from; I'm not afraid to work on things but sometimes I don't know what I'm looking for and the service manual is less than helpful in my opinion. I didn't remove the tank to do this work so it's possible when poking around with such little room I bumped or jarred something that would explain everything. Any assistance is appreciated. Thanks.
 

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Not bad list so far by everyone. Start simple before going to the difficult stuff. Check the manual for trouble shooting as well. There may be a few more suggestions in it.
 
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Discussion Starter #8
Wow, I didn't expect to see so many responses when I got back from dinner, thanks everybody!
 
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Discussion Starter #9
I didn't see you mention it so I thought I'd throw it out there. Did you try to adjust the idle?

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Not yet. When I started to get paranoid that something else went wrong I decided to stop until I consulted the forums. Could it be as simple as increasing idle speed? I don't recall what it idled at before I made the changes, but I do feel its a bit low based on what the service manual says.
 
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Discussion Starter #10
Not bad list so far by everyone. Start simple before going to the difficult stuff. Check the manual for trouble shooting as well. There may be a few more suggestions in it.
I didn't think about the troubleshooting section of the manual, I'll take a look at it.
 
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Discussion Starter #11
Most probable cause.
Either plug the vacuum line, or cap the fitting on the throttle body.
This is the first thing I checked when it wouldn't run right. I have it plugged but will eventually cap it on the throttle body because I don't like the extraneous hose dangling...
 
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Discussion Starter #13
I let the bike cool down and tried adjusting the idle speed. So far the results are promising but it's difficult to tell quickly since it runs fine when the engine is warm. I'll check it in the morning and see how things are. Thanks again to everybody for their assistance.
 

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Not yet. When I started to get paranoid that something else went wrong I decided to stop until I consulted the forums. Could it be as simple as increasing idle speed? I don't recall what it idled at before I made the changes, but I do feel its a bit low based on what the service manual says.
It could easily be that simple. Post what you come up with.

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Discussion Starter #16
It could easily be that simple. Post what you come up with.

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So far it seems to have been this simple. I'm sure there's a logical explanation as to why removing PAIR and flapper lowered my idle speed significantly. I increased it to ~1300rpm and it remains running without issues just like it did before. I have yet to ride it since I've got more work to do on it, but my heart-rate has returned to normal. :)
 
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Discussion Starter #17
I did the pair mod to my 2002 rc51 and the bike is smoking bad now. Any ideas?? I'm obviously not gonna ride it until I figure this out. I followed the directions to the T.


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Did you epoxy off the stock valve covers or use block-off plates? If the prior, was the epoxy fully cured or did you use anything combustible to plug the hole that would explain the smoke?
 
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