763 won't start

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imageres

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Aug 23, 2010
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I have a Bobcat 763 and am having problems starting it. The problem seems to be centered around the kill solenoid. I have noted that when you turn on the ignition the kill solenoid pulls back as you would expect. However, as soon as you start to crank the motor the kill solenoid releases thus cutting off the fuel to the engine. I am tending to suspect the timing relay that is wired just in front of the solenoid. I tried holding the kill soenoid back by hand and found that the motor then starts and continues to run as long as I hold the solenoid back. Does anyone have any experience with this sort of problem or knows how to trouble shoot this issue? Thanks Doug
 

frogfarmer

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Jul 30, 2010
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I would check voltage drop under a load. Low voltage on cranking will cause all kinds of problems with solenoids and relays designed for 12v operation. Most batteries will hold 10v or better under load. I have seen 6v roll a motor over with relative ease.
 

OldMachinist

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I would check voltage drop under a load. Low voltage on cranking will cause all kinds of problems with solenoids and relays designed for 12v operation. Most batteries will hold 10v or better under load. I have seen 6v roll a motor over with relative ease.
Likely the hold coil in the solenoid is bad. Disconnect the plug and check the resistance between the black wire and each of the other wires. The pull coil should show about 10-11 ohms and the hold coil .4-.5 ohms. The hold coil wire is normally white and the pull coil red.
 

Tazza

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Likely the hold coil in the solenoid is bad. Disconnect the plug and check the resistance between the black wire and each of the other wires. The pull coil should show about 10-11 ohms and the hold coil .4-.5 ohms. The hold coil wire is normally white and the pull coil red.
As OM said, probably a bad hold coil.
If its out of adjustment it can drop out too.
An easy test is to apply power to the hold coil and pull the lever back manually, see if it stays in place, if it doesn't, you need a new coil.
 
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imageres

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Aug 23, 2010
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I would check voltage drop under a load. Low voltage on cranking will cause all kinds of problems with solenoids and relays designed for 12v operation. Most batteries will hold 10v or better under load. I have seen 6v roll a motor over with relative ease.
Thanks for all the help. I checked out the battery and the Kill Soleniod and found that the problem was in fact the timing relay attached to the soleniod. My problem now is finding this part at a reasonable price. The local Bobcat dealer wants $120.00 for this item. I am also interested in rebuilding a V2203 block that I now have sitting in the shop. Again this would only make sence if I can find a reasonable source for the engine parts. Any suggestions?? Thanks All
 

Tazza

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Thanks for all the help. I checked out the battery and the Kill Soleniod and found that the problem was in fact the timing relay attached to the soleniod. My problem now is finding this part at a reasonable price. The local Bobcat dealer wants $120.00 for this item. I am also interested in rebuilding a V2203 block that I now have sitting in the shop. Again this would only make sence if I can find a reasonable source for the engine parts. Any suggestions?? Thanks All
The first thing with the engine is to make sure the head is not cracked. If it is, you are up for over $1k right there.
No matter how you go, the rebuild won't be super cheap. New pistons/rings/bearings/gaskets. You then need a machine shop to install new sleves in the bores, machine them to size, deck the block, re-co the head. Get the fuel injection side checked/cleaned. The last one i fully did up cost me about 2k in parts, i got the machine work done for nothing. I was lucky enough to have a good head so it kept the price down.
 

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