[stryder]

If a hose came off or split, you will see/hear the gas splashing around in the tank when the bike is turned on, filler cap open. If it's not that, I'm inclined to say those are the symptoms of a swarfed up Crank Position Sensor, other than it started up and then died, but the turning over and not sparking all of a sudden/out of the blue, sure sounds like the CPS should be pulled and cleaned off. It's the sensor to the left of the water pump, behind the hoses. It can be pulled out and replaced with the hoses attached, but not without some dififculty. It may be worth a try.

 

[stryder]

would I see spark to the plugs if the sensor were mess up?

No, that's what triggers the ecu to fire the plugs

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I clean mine annually as part of my PM program when I put the bike away for winter storage, so it might be worth the effort to clean it off even if it's not the issue in order to avoid/help reduce the prospects of a CPS non-starting issue in the future.

 

[stryder]

I did an earlier post this morning when I tried to start my 2000 st4 and it started fine then died, it will crank over fine but makes no atempt to start. Since then I have checked for spark at the plugs and there is none , I removed the cps and cleaned it , it looked ok, changed all the relays arround, disconnected and reconnected the battery, tried putting my stock chip in the ecu, checked all fuses, don't know where to go from here, any suggestions

Have to ask: Did you ground the plug against the engine with a block of wood or other insulated tool when you cranked it over?

 

[stryder]

did an ohm test on the sensor and as far as ohms its within limits , I don't know if that means it cant be bad or not, this afternoon I am going to clean off the face with some steelwool , leave one of the shims off and put it back in and try it again, I am running out of ideas, anybody got any Ideas? again the bike has been running perfect, started up ran for about 10 seconds and then shut off just like you were turning the key off, when you try to start it it cranks over fine but does not even try to spit or start (no Spark to the plugs)thanks

Based on the "just stopped" scenario, I'm sorry, but did you eliminate for sure that it's not a spat fuel line? They too do that, ie bike runs great and then just stops if the line is spat. I didn't see a follow-up on that re checking the splashing in the tank when the ignition is energised. Also, did you read Paul's post #20 IIRc re the sidestand and kill switch and eliminate those as well?

Since the bike was running well before hand and then just stopped, I doubt there is much value in following up on CPS shims etc, if the sensor seems okay. As mentioned above, coils issues could be the next place to start looking, if all the above has been eliminated.

 

[stryder]

IDK. A better signal with a smaller gap "could" help. It might not be a good idea to unilaterally rule it out. Just sayin'. Another bit with the CPS signal is that the fuel pump will prime with the key on then it will start up again when the CPS detects a signal.

On the fuel line aspect, they tend to pop more often with a full tank for some weird reason.

Have a good one.

No doubt all the above re the cps shim etc *is* of some value, and I was just making the assumption the bike was starting up and running well just before it died. I *can* see what you mean if the cps is getting weak but still passes the ohms test, but might suddenly need a tighter gap. Do those sensors "fade" or just die? But he stated first that there was "a" shim, and then that there were 2 shims. Why 2 shims? Did ST4's come that way? My ST3 has only 1.

 

[stryder]

First of all, thank you for all the help, I got it, charged the battery to full, installed the sensor without one of the shims , after cleaning it with oooo steel wool and she had spark, had to have been the sensor, Thanks again for all the great input.

Glad to hear that. How old is that battery? Maybe a new battery is a good idea. They do crap out over time, mine did after 6 seasons. As stated elsewhere, relatively cheap insurance.

 

[stryder]

...I wish there was a metal fuel line kit to replace the hoses with.

Seriously, I don't know why there isn't or why one couldn't be whipped up at home. This has been on my mind for years now, getting somne Al or SS tubing and bending/shaping it etc. to fit. One of these winters, I'm going to try doing that in my spare time.