DT/tclh 140 won't Idle

[Solarman]

Is this a new problem, or was it not firing before?
If not firing before then check the two pulse coils under the flywheel for those two cylinders (you should have one for each cylinder). You should be able to identify which is for each cylinder by using the wiring schematic in your manual for your motor.
You will need an ohm meter to test them.Don't remove them until tested. Read the section on replacing them before removing, some require special adjustment to flywheel.
Let us know how it's going.

[bartow buddy]

Is this a new problem, or was it not firing before?
If not firing before then check the two pulse coils under the flywheel for those two cylinders (you should have one for each cylinder). You should be able to identify which is for each cylinder by using the wiring schematic in your manual for your motor.
You will need an ohm meter to test them.Don't remove them until tested. Read the section on replacing them before removing, some require special adjustment to flywheel.
Let us know how it's going.

I'm thinking that it has been like this the plug wires would shock you when you pulled them off and sparks off of #2 so I put a new coil and plugs in it and the top 2 plugs don't look used at all but the bottom 2 are looking like you would expect them to. that is when I pulled the top 2 wires and the motor didn't change a bit and made me wonder if it was in the safe mode from the oil sensor but I don't know and the book doesn't say how that works whether it cuts 2 cyl. or just limits the rpm. on all of them. It does say that the kill switch can cause it to misfire. will let you know what I find. Thank you

[Solarman]

dt140,carbs, running issues

The kill switch if not right would normaly short through all the plugs, it shorts the cdi circuit that feeds all the plugs. The pulse coils operate each cylinder, and tell the cdi circuit which coil gets the spark. The gear counting coil tells the computer the speed of the crank. The tps advances/ changes the timing for the speed and throttle valve opening.
If your carbs have been taken apart for cleaning the tps may be adjusted wrong since them. Read the section on adjusting tps. Your timing could be off, if tps is not properly set up?
If you want to check for spark, take all the plugs out, wrap a stiff bare piece of wire around the threads then secure to a good ground. Plug each wire back to its respective plug. Turn the motor over and see if the plugs are arcing, if you do at night it is easier to see spark, but can see in daylight too.
Let us know, how its going. Good luck

[BillCon]

Well, normally those would affect all the plugs, the two stroke V6 is hard to diagnose when idling because its so eratic and sounds like hammered crap, as for the TPS the easiest way I, found to adjust it without shop tools was to rotate it counter clock wise till it stops, then set your idle speed to 700 rpms then very slowly turn the TPS clockwise until the idle jumps up, then back it off slowly till it drops back down the tighten the screws, because it come in at 3 degrees advance throttle, the manual is pretty good at helping set those things, then you can go back to the missing issue so your not fighting two problems at once, keep us posted we are curious as to what you find on this.

[bartow buddy]

Well, normally those would affect all the plugs, the two stroke V6 is hard to diagnose when idling because its so eratic and sounds like hammered crap, as for the TPS the easiest way I, found to adjust it without shop tools was to rotate it counter clock wise till it stops, then set your idle speed to 700 rpms then very slowly turn the TPS clockwise until the idle jumps up, then back it off slowly till it drops back down the tighten the screws, because it come in at 3 degrees advance throttle, the manual is pretty good at helping set those things, then you can go back to the missing issue so your not fighting two problems at once, keep us posted we are curious as to what you find on this.

Bill Con this is a dt140 in line 4 cylinder I will try to adjust it your way and see if that helps and will let you know. Thank You.

[bartow buddy]

The kill switch if not right would normaly short through all the plugs, it shorts the cdi circuit that feeds all the plugs. The pulse coils operate each cylinder, and tell the cdi circuit which coil gets the spark. The gear counting coil tells the computer the speed of the crank. The tps advances/ changes the timing for the speed and throttle valve opening.
If your carbs have been taken apart for cleaning the tps may be adjusted wrong since them. Read the section on adjusting tps. Your timing could be off, if tps is not properly set up?
If you want to check for spark, take all the plugs out, wrap a stiff bare piece of wire around the threads then secure to a good ground. Plug each wire back to its respective plug. Turn the motor over and see if the plugs are arcing, if you do at night it is easier to see spark, but can see in daylight too.
Let us know, how its going. Good luck

Solar Man the book says to rotate the tps. clockwise with running engine and adjust back counter clockwise, i have done this several times and when it leaves the high idle and you can hear the change i lock it down bud i can back the idle screw on the #2 carb. completely back and it idles at 900 rpm. and sounds like it is running smooth you can pull the top 2 plug wires off and can't see a difference on the tach. or hear a difference in the engine it still runs smooth. I will try the bare wire around the plugs and see if that tells us something before pulling the flywheel off. will try to run the air screws a little richer to see if it will idle it down to 7 hundred. and the idle adjust doesn't change it up or down on either of the 5 settings. but I read that it wouldn't work unless it was running above 700 rpm. thank you

[BillCon]

Have we looked into the possibility of an air intake leak in this post? you should be able to stall the motor by backing off the idle speed screw, that could also explain the miss on the top cylinders

[bartow buddy]

Have we looked into the possibility of an air intake leak in this post? you should be able to stall the motor by backing off the idle speed screw, that could also explain the miss on the top cylinders

By backing off are you saying richer or leaner, and there is not a leak in the intake I put gasket sealer on both sides of all the gaskets and checked the float height on all the carbs yesterday and they are .70 book says .67 to .75 all the jets are correct per book and throttle lever is 6.30 and adjusted per. book. the book says to turn the tps. clockwise and then back counter clockwise but when you loosen the screws and touch the tps. some times it will speed up or die without ever moving it. I had it running on the hose today and it was doing fine until I either loosened the tps. or turned the idle speed adjustment knob and then it would speed way up or in case of the tps it would die when I loosened the screws. the next time I run it I'm going to try and disconnect both and see what it does. Thank you

[bartow buddy]

The kill switch if not right would normaly short through all the plugs, it shorts the cdi circuit that feeds all the plugs. The pulse coils operate each cylinder, and tell the cdi circuit which coil gets the spark. The gear counting coil tells the computer the speed of the crank. The tps advances/ changes the timing for the speed and throttle valve opening.
If your carbs have been taken apart for cleaning the tps may be adjusted wrong since them. Read the section on adjusting tps. Your timing could be off, if tps is not properly set up?
If you want to check for spark, take all the plugs out, wrap a stiff bare piece of wire around the threads then secure to a good ground. Plug each wire back to its respective plug. Turn the motor over and see if the plugs are arcing, if you do at night it is easier to see spark, but can see in daylight too.
Let us know, how its going. Good luck

I believe that the tps. or the idle speed adjustment one or both are bad if I just loosen the screws after turning it clockwise and tightening them to start it when I loosen them while holding the tps stationary it will either speed up or die is there supposed to be some kind of gasket or plate behind the tps. the book does not show one but I noticed in a trouble shooting section that it mentioned a backing plate. Thank you.

[Solarman]

dt140, carbs, running issues, setting tps

My motors are efi, I don't adjust my tps the same as you are trying to. Your tps its set according to all 4 butterflies, mine had only the one. I set mine by ohms, my wot is 440, and (throttle cable disconnected), idle is 110. With throttle connected idle is at 120, half of my wot reading.
Basically by my manual, if I remember correctly, my butterfly is set at 3° open, and the tps is supposed to read 3 volts, but that required the jumper wire that connects the volt meter inline with the ecm to measure but, I didn't have that, so I improvised. I had two motors, so I matched my other motor by the ohms at wot, and at idle.
For your motor, I would connect the ohm meter, max out the throttle (key off - not running) adjust tps to highest reading, snug the screws down, return to idle, check ohms, (should read half wot) disconnect throttle check ohms (mine is 10 ohms less than idle). You might need to adjust the idle stop screw to prevent over revving.

If you still can't get tps set right, might call dealer and ask the price to check & set the tps on your year 2 stroke.
Good luck, let us know how you're doing.

[BillCon]

***, this problem is hiding itself pretty good from what, I, read here, Ok, how about I, throw this on the table, and is more of a question for Solarman to chime in on, could Bartow's motor have a reed valve causing this?

[Solarman]

dt140, carbs, running issues

Well Billcon I seem to feel that timing, or fuel delivery would have to be corrected before any major steps like reed valves would need to be looked at.
The carbs have been soaked and cleaned. In most cases someone has removed the tps for that to be done. Once that was done it has to be set up to where timing is right for the throttle again. The throttle position sensor (tps) advances & retards the timing according to the opening of the butterflies.
So bartow buddy, if the carbs have been disassembled, and reassembled correctly, with all 4 air mixture screws set the same. Then the tps needs to be adjusted properly. And if you have good wires/ coils in place, then the idle stop screw might be the only other adjustment that should be needed.
Providing you haven't changed the pulse coils positions, or gear counter coil position?
Good luck let us know how it's going.

[bartow buddy]

Well Billcon I seem to feel that timing, or fuel delivery would have to be corrected before any major steps like reed valves would need to be looked at.
The carbs have been soaked and cleaned. In most cases someone has removed the tps for that to be done. Once that was done it has to be set up to where timing is right for the throttle again. The throttle position sensor (tps) advances & retards the timing according to the opening of the butterflies.
So bartow buddy, if the carbs have been disassembled, and reassembled correctly, with all 4 air mixture screws set the same. Then the tps needs to be adjusted properly. And if you have good wires/ coils in place, then the idle stop screw might be the only other adjustment that should be needed.
Providing you haven't changed the pulse coils positions, or gear counter coil position?
Good luck let us know how it's going.

I haven't taken the flywheel off yet, unless the previous owner moved the pulse or secondary coils has not moved. I have had an emergency come up last Thursday night and had to take a couple of days away from this problem but plan to get back on it tomorrow. Thanks for you Guys helping me Ellis

[Solarman]

dt140, carbs, running issues

Once you have adjusted air mix screws the same, then try to set tps, by manual if able. If not able by manual, can try as I did, but need to use ohm meter add I did.

My motors are efi, I don't adjust my tps the same as manual/ how you are trying to. Your tps its set according to all 4 butterflies, mine had only the one (if all yours are moving identically, use the one the tps is connected to).

I set mine by ohms, my wot is 440 (yours may read different ohms at wot?), and (throttle cable disconnected), my ohms at idle 210. With throttle connected idle is at 220, half of my wot reading. Basically by my manual, if I remember correctly, my butterfly is set at 3° open, and the tps is supposed to read 3 volts, but that required the jumper wire that connects the volt meter inline between tps and the ecm to measure volts, but I didn't have the jumper write, so I improvised. I had two motors, so I matched my other motor by the ohms at wot, and at idle.

For your motor, I would connect the ohm meter, max out the throttle (key off - not running) adjust tps to highest reading, snug the screws down, return to idle, check ohms, (should read half wot, if not, get as close as you can. disconnect throttle check ohms (mine is 10 ohms less than idle). You might need to adjust the idle stop screw if over 10 ohms to prevent overrevving. Good luck, let us know how you're doing.

Hope the emergency is ok, and everything is better.
When able to get back just let us know how you're doing. Good luck.

[BillCon]

Solarman is there two different TPS sensors used? one for EFI and one for Carbed motors? because If, this motor is an 87' and a carburated model his TPS may not have Potentiometers in it to set with an ohlm meter, he may have the same one I, do that is simply an on/off signal switch that bumps the timing 5 degrees at 3 degrees advance throttle, and then again at 20 degrees, I, usually set mine with a continuity meter.