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Discussion Starter #1
I'm looking for a little help, fixed my '99 748 so well it won't start now. I had a problem with her stalling at what I thought was temperatures of around 210f. Ran it for a while tonight to check cooling fan and it came on around 205 plus or minus. Thinking maybe it was the RR I pulled the battery, removed neg. then pos. all with the key off and kill switch off. I unplugged both connectors for the RR. I then re-attached the battery, pos then neg, with the RR unplug so I had access to teh connector terminals and took all the reading per instructions on Electrosport troubleshooting page. Everything tested per spec using the Diode test function. Disconnected the battery, re-attached the RR cables, and put everything back together, relieved that I didn't have to invest in a new RR. Lastly, connected pos then neg and torqued everything down. You guessed it - she wouldn't start. Just turned over but never fired. I then took everything apart again to check connections but still no luck. Anyone have a clue? Did I do some serious damage to the ECU or RR by connecting to the battery during the test? Any help is much appreciated. Thanks to all.
 

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Double check your kill switch. I've had so many come up bad I don't touch that thing. I only turn mine of with kickstand switch or key.
 

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Discussion Starter #4
It seems like no fire - usually fires right up with about 1/2 of crank. Just keeps cranking, similar to the problem was trying to fix... except when hot.
 

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With my 748 I once had a heat related electrical failure. The bike wouldn't re-start after it had been shut down normally. Once it cooled off it would turn over again. I finally found that the coil connection to the starter contacter was the issue. The female pins would expand enough from engine and exhaust heat that they would no longer make contact. The solution was to crimp the female barrels a bit until they fit the male connector really tight. I am suspect of connectors on my 748.
 

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Discussion Starter #7
I'm not hearing the fuel pump when switched on, looking into tht right now.
 

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Make sure you attached the earth connections correctly.

Sounds like you accidentally loosened a wire somewhere during your troubleshooting.

SF
 

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Discussion Starter #10
Yep, unplugged relays under seat and plugged back in. Turned on key and switch... fuel pump came on. Hit the starter and it cranked a few times and started! Let it run 4 minutes or so and shut it down. Tried again and would not start, no fuel pump noises. Something in the fuel pump relay circuit?
 

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Discussion Starter #11
Engine management relay bad or going bad. One has 43 ohms across the coil, doesn't work so well I guess. The other one has 80 Ohms across the coil. The left one energizes with the ingnition, the right one did not. I reversed them and the pump came on, started up. I think this issue may also be causing the high temp shut down since it's between the seat and the exhaust. The relay get's hot, fails and causes fuel starvation. Once it cools off and the relay works, just barely. I'll put new ones in and post the results. Thanks for everyones help.
 

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Yep, unplugged relays under seat and plugged back in. Turned on key and switch... fuel pump came on. Hit the starter and it cranked a few times and started! Let it run 4 minutes or so and shut it down. Tried again and would not start, no fuel pump noises. Something in the fuel pump relay circuit?
I would check the saftey circuit - Kickstand switch + safety relay
 

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Discussion Starter #13
Pretty certain I tracked it down to the management relays under the seat. One clicks and the other doesn't. I check resistance and teh one that does not energize was 40 ohms, the other was 80 ohms. I pulled both of them and reveresed the install, fuel pump primed and started right up. May also be the problem with fuel starvation at temperature - the relay fails. I'll install new ones and post the results. Thanks to all for your suggestions.
 

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I went through the same problem right after I bought my 996s. Went through every relay, checked the fuel pump, replaced the battery etc. I know it sounds weird, considering mine would turn over but the fuel pump wouldn't prime, but giving the battery a good charge seemed to take care of it. BTW, a relay for an 88-02 GM AC unit is a perfect match for the rear relays. One thing that did come up later was a ground issue in the ECM that caused me to sputter and hesitate around 5K RPM. That could have been causing my original issue as well. There is an old computer geek trick where you toss a flaky board in the oven to re-melt the solder connections which honestly works. Since the board from the ECU is pretty well in there, I just pried the top off, pulled out the EPROM and hit the board with a heat gun until I saw flux bubbling and solder getting that silvery look when it's fluid. You could be experiencing the same issue. If you're not getting good ground through the ECM it can keep those relays from activating properly. It took me tracing damn near every wire in the bike to figure out my ground issue was in the ECM.
 
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