B7800 cranks but will not start

   / B7800 cranks but will not start #1  

tempkubotaman

New member
Joined
Aug 13, 2012
Messages
3
Location
Junction City, Oregon
Tractor
B7800
I was called by a neighbor that their tractor was running fine one min, then when shut off, failed to start again later. Engine cranks strong... just won't fire. I checked bat voltage and it was fine, checked fuel system from pri filter towards fuel pump and that was good, return fuel supply was good too.

Removed fuel shutoff sol and started machine (i use my finger to push barrel in fuel pump to cut off engine) I measured resistance across fuel shut off sol terminals and got 20 ohms (and dropping) so I bought a new sol... installed it and nothing.

As far as I know... all safety switches are in working order, ie; I have placed pto in gear and engine won't crank, didn't push clutch in and also... engine won't crank, ect... ect...

I guess what my question is... are there any safety switches that (if serviceable) will allow the engine to crank? Are any designed to allow the engine to crank, yet halt fuel flow... therefore not allowing the tractor to start? I'm at wits end on this one and I just know that there is probably a quick fix out there. One more thing, pretty hard to diagnose by myself but I could swear there was NO power readings at that little connector (to the fuel shut off sol) when the key is turned on to crank... nor turned off. I think that is where my problem is but must first rule out these stupid safety switches they put on these tractors.

Thank you!
 
   / B7800 cranks but will not start #2  
G'day and :welcome: have you checked for a seat switch? Also have you checked the fuse that powers the shutdown?

Jon
 
   / B7800 cranks but will not start
  • Thread Starter
#3  
Hi Jon, I have checked the safety switches.... from what I was told at the dealer, if a safety switch is inop or if the situation exists to not allow the tractor to work ie, not sitting in seat, clutch not engaged, pto in gear, ect... then the engine will NOT crank at all (and it cranks just fine.... it just won't start and run) The guy at the dealer had sort of a puzzled look when he told me that so I was trying to confirm or deny his statement.

To answer your question about the fuse box.... Power is at fuse box and the fuse for the fuel sol (30A)is ok. Also, there is power at engine stop fuse... and that fuse is OK. Do you know where that engine stop relay is on the machine? I tried removing the inst panel but afraid to rip and tear it off. Looks like screw driver slots on top but I'm at a loss on how to open it up... sure hate to break anything!

Thanks for keepin tabs on this btw, Dave
 
   / B7800 cranks but will not start #4  
Most of the safety switch wwhen open will not allow starter engagement. I'd look at fuel delivery. Perhaps a clogged fuel strainer at the tank out let.
 
   / B7800 cranks but will not start
  • Thread Starter
#5  
Well, as I wrote before... the engine starts and runs just fine (with the fuel shut off sol... removed) But thanks anyways for throwing your 2 cents out there. The problem is the engine won't start (it cranks) with the fuel sol installed...
 
 
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