90s DT60 wont stop!!!

[aidan.calder]

Bit of a funny one my old dt60 has stopped stoping. in runs well and still throws my little 14" shakespear across the water like its prop is on fire but no matter what i do it wont stop so i have to choke it or disconnect the fuel line and let it run dry. I know that the red and blue wire is ment to kill the engine when grounded but this does nothing. I have stripped and cleaned all the bullet connectors and the CDI unit connector but all attempts have failed. A mate suggested that the CDI unit might be faulty or the ground has corroded but I dont understand if that is the case how the engine still runs as surly the coil packs wouldnt get a fire signal. Any help or suggestions would be appreciated as i dont fancy shelling out on a new unit if i dont have too.

 

[mphelle8vld]

Re: 90s DT60 wont stop!!!

With the motor at idle and the ignition off, pull the emergency stop, if it stops, you may have a bad ignition switch, if it's still running, pull the plug wires, if it stops, troubleshoot the wiring to find out why the coils are still getting power, if it's still running you may have some carbon buildup that gets hot and acts like a glowplug in the cylinders. This only happens with a really lean idle mixture so I would remove and really clean the carbs. You can try that and then start using an additive meant to remove carbon deposits or remove the head and remove them manually.

 

[aidan.calder]

Re: 90s DT60 wont stop!!!

unfortunately the engine does not thave an emergancy stop. all the trouble shooting has been done at the engine end with the wireing loom disconnected. the control box is non standard and the ignition and choke controls have been built with waterproof switch's that have been built into the dash so my first move was to bypass them. I have pulled the HT leads and this does kill the engine and have cleaned and replaced most of the connetors back to the CDI plug. I cant find a fault with the wiring as such. as i said the only sort of advice i ave had is that the CDI might have lost its ground but i dont see how the engine would run if it had but i dont know enough about how the CDI works to trouble shoot any further.

 

[mphelle8vld]

Re: 90s DT60 wont stop!!!

It would be hard for me to troubleshoot with all the custom rewiring, where are you located? I have a spare control box that would eliminate everything from the motor forward.

 

[aidan.calder]

Re: 90s DT60 wont stop!!!

er ....UK. I have eliminated the control box electrics. The origanl plug had been chopped off when i got the engine, i diddnt trust the mess of crimps and choc connectors so i tested everything and proved all the electrics befor i wired the engine start button, choke button and kill cord and engine kill switch. they have all worked fine and when the problem started I eliminated each component by disconnecting the new loom and shorting or isolating every cable at the engine so as it stands the only thing connected to the engine is the fuel line control cables and a battery. All the electrics are direct to the engine. I know the choke is okay as i can make that work the electric start is okay and the low oil buzzer have all been tested as has the Aux 12v feed. I have double check the wireing against a suzuki workshop manual and the blue wire with a red stripe (which was wired up to the kill cord and engine stop button with the negative feed) befor when i first got the engine when shorted to a negative or the engine block killed the engine. when I short this to the block or the aux negative or the negative on the cdi which if i have read the manual right is ment to stop the fireing signal from going to the coil packs and hence stopping the engine. Is what i am doing right or am i totaly barking up the wrong tree.

 

[mphelle8vld]

Re: 90s DT60 wont stop!!!

Not familiar with the UK version but looking at a similar schematic, you have the correct blue/red wire but it looks like it travels to the ignition charge coil where it should short the signal to the cdi when grounded. You might want to pull the flywheel to see if there's a loose or burned connection to the charge coil. Let us know what you find.

 

[aidan.calder]

Re: 90s DT60 wont stop!!!

will do. i will let you know what i find.

 

[mphelle8vld]

Re: 90s DT60 wont stop!!!

It could also travel to the pulser coil, can't tell on my schematic, just follow your wire and check continuity, you might get lucky and find a corroded banana plug for your wire just under the flywheel shroud so you wouldn't have to remove the flywheel.

 

[aidan.calder]

Re: 90s DT60 wont stop!!!

okay I have followed the wire to the connections box and i chopped out the corroded bullet connector and replaced it. but the red and blue cable only goes to the CDI unit there are only 3 cables comming from the pulser coil 2 white and a black and they connect to the CDI unit in the connector box. I am now totally lost any further ideas

 

[mphelle8vld]

Re: 90s DT60 wont stop!!!

Indeed a strange one, does your manual's schematic show that wire traveling straight to the cdi? My generic schematic is not much help, so I can't help with the wiring but I think I would use the choke at idle to shut it down, rather than of buying a new cdi to test that theory.