LT300e Won’t turn off with key

[Jd101506]

Hi all-

I’ve got a LT300e that I’m working on.  The last two days I noticed as I’ve been testing it, it won’t turn off with the key. The kill switch still works to turn it off, as does everything else (lights, neutral light, reverse, starter, etc). So I guess I’m taking votes on what to do here… Ignition the issue? Wiring grounding issue somewhere? 
Not sure where to start so any help would be appreciated! 

[Gwbarm]

When you turn the switch off does everything else go off but the engine stays running.

[Jd101506]

Yep! 

[Mech]

My guess would be that the key switch has two parallel circuits in it and one switches the battery ignition and the other switches the accessories.

We could confirm that with a wiring diagram, if we knew the year and found a service manual, or, you could disconnect the switch at it's plug and test each circuit with a multimeter..  or test light.

[Jd101506]

I’ve been trying to find the correct service manual here actually. It’s a 1987 LT300E. I haven’t yet found the correct one in downloads. 

[Mech]

I have several diagrams.. 

Have a look at how many wires are coming out the back of the switch, and their colours.

If it has five, two are for turning the power on to the accessories, two are for shorting the ignition..  The ignition kill pair might not be switching, or they have a break in one of them.

I think that your switch might be like this one. The  wire colours may be different.

output.pdf

[Jd101506]

8 hours ago, Mech said:

I have several diagrams.. 

Have a look at how many wires are coming out the back of the switch, and their colours.

If it has five, two are for turning the power on to the accessories, two are for shorting the ignition..  The ignition kill pair might not be switching, or they have a break in one of them.

I think that your switch might be like this one. The  wire colours may be different.

output.pdf 37.21 kB · 0 downloads

This is awesome! I’m having a hell of a time finding the repair manual for this LT300 here but I was able to find every other Suzuki model… 

 

I’ll pull that switch and check the runs between. Thank you! 

[Mech]

That is out of a lt160e manual. A quick browse of google and it seems like it might be similar in design (though not the same specs of course).

If it's not in the manuals section I can upload it if you want.. 

oh..  It's 1998 onwards too..

[Gwbarm]

Most of the manuals I saw were newer also, haven't really found one for the 87. Its got to either be in the switch or wires , start tracing wires take the switch apart and make sure they are not corroded or loose.

[Savage3]

On 7/14/2023 at 7:33 PM, Jd101506 said:

Hi all-

I’ve got a LT300e that I’m working on.  The last two days I noticed as I’ve been testing it, it won’t turn off with the key. The kill switch still works to turn it off, as does everything else (lights, neutral light, reverse, starter, etc). So I guess I’m taking votes on what to do here… Ignition the issue? Wiring grounding issue somewhere? 
Not sure where to start so any help would be appreciated! 

Check for battery power at S terminal on solenoid while engine is running. 

 

There should only be power when pushing start button.

If there is power, either switch is bad or solenoid is bad. 

 

Let us know results and we can move to next test.

[Jd101506]

Ok!  

Will check and report back.  So oddly, and I can't make sense of this, ever since I "lost" the ability to turn the fourwheeler off with the key, its been running really odd.  It'll startup great, and it will run for about 3-5 seconds then its like someones letting the air out of a balloon... It slowly loses RPM at idle.  I can throttle up and it throttles up evenly and instantly, no hesitation or surging... then as it comes back down to idle it will slowly die again.  No chances were made to the fuel system, pump, carb, or anything but for giggles I made myself a auxiliary tank and I mainlined fuel directly into the carb bowl... Same symptoms with the fuel tank + lines.  Its really strange.  I've tried resetting the carb idle, and the mixture screw, the mixture screw makes ZERO difference, it'll just start smoking more as it richens up... If I bump the idle speed screw up it'll stay running.  

Before I had this issue the bike would start and idle forever without complaint.  Hell it sounded better than half the fourwheelers I had.  Since that time I changed the plug to a new one (Same plug, same gap, just new), changed the oil and filter, and swapped the tires.  I also cleaned out the airbox since it was a little funky.  

I doubt, but I can't rule out they are connected but this slowing-idle-to-inevitable-death situation started the same time the fourwheeler not turning off started.  Just as another piece of information. 

I'll test for battery on the S terminal and I'll start tracing wiring tonight.  

Thanks everyone!

[Savage3]

49 minutes ago, Jd101506 said:

Ok!  

Will check and report back.  So oddly, and I can't make sense of this, ever since I "lost" the ability to turn the fourwheeler off with the key, its been running really odd.  It'll startup great, and it will run for about 3-5 seconds then its like someones letting the air out of a balloon... It slowly loses RPM at idle.  I can throttle up and it throttles up evenly and instantly, no hesitation or surging... then as it comes back down to idle it will slowly die again.  No chances were made to the fuel system, pump, carb, or anything but for giggles I made myself a auxiliary tank and I mainlined fuel directly into the carb bowl... Same symptoms with the fuel tank + lines.  Its really strange.  I've tried resetting the carb idle, and the mixture screw, the mixture screw makes ZERO difference, it'll just start smoking more as it richens up... If I bump the idle speed screw up it'll stay running.  

Before I had this issue the bike would start and idle forever without complaint.  Hell it sounded better than half the fourwheelers I had.  Since that time I changed the plug to a new one (Same plug, same gap, just new), changed the oil and filter, and swapped the tires.  I also cleaned out the airbox since it was a little funky.  

I doubt, but I can't rule out they are connected but this slowing-idle-to-inevitable-death situation started the same time the fourwheeler not turning off started.  Just as another piece of information. 

I'll test for battery on the S terminal and I'll start tracing wiring tonight.  

Thanks everyone!

Yes sir,

Sometimes, the wires go through the neutral switch or other safety switches after pushing start button. 

We may have to narrow it down.

In my humble opinion, it would be a good idea to start with checking power at the solenoid.

Current should only be at the (hot) or "S" terminal on the solenoid while pushing the starter button.

Once the engine is running and you are no longer pushing start button, there should be no power on that circuit.

If there is power while engine is running, then we simply work backward through any safety switches to the starter switch.

It appears, either the contacts in the solenoid are getting stuck or one of the switches has a direct short.

 

[Mech]

I would suspect that either the key switch or the wiring has a bad connection and the engine is running off the charging circuit, or rather the charging isn't getting to the battery and diverting into the ignition even if you turn the key off.

Check the fuses, especially any charge fuse if it has one.

[Mech]

Looking in the 160e manual it looks like an internal fault in the key switch could cause it..  but that's for the 160..  but it does link with the no turn off problem.

Check the earths too, it could be a feed back through a non earth.

[Jd101506]

1 hour ago, Savage3 said:

Yes sir,

Sometimes, the wires go through the neutral switch or other safety switches after pushing start button. 

We may have to narrow it down.

In my humble opinion, it would be a good idea to start with checking power at the solenoid.

Current should only be at the (hot) or "S" terminal on the solenoid while pushing the starter button.

Once the engine is running and you are no longer pushing start button, there should be no power on that circuit.

If there is power while engine is running, then we simply work backward through any safety switches to the starter switch.

It appears, either the contacts in the solenoid are getting stuck or one of the switches has a direct short.

 

Alright. I finally got my tires and ran it around the yard a bit. This thing is just fun as all get out. Definitely need to address the carb being dirty but it went! After I got back from ruining my lawn, I pulled my multimeter and took this reading: 

 

the solenoid terminals read that off or on, running or not. 

[Savage3]

22 minutes ago, Jd101506 said:

Alright. I finally got my tires and ran it around the yard a bit. This thing is just fun as all get out. Definitely need to address the carb being dirty but it went! After I got back from ruining my lawn, I pulled my multimeter and took this reading: 

 

the solenoid terminals read that off or on, running or not. 

There is the problem sir! Take solenoid off the vehicle, bench test.

When power is applied, you should have continuity between terminals.

When no power is supplied, you should not have continuity.

In short, either solenoid is welded or you have constant power in that circuit.

First step, bench test solenoid.

 

I have to go to work Boss. If this doesn't make sense, search you tube for bench testing a solenoid.

 

I'll check back later.

[Jd101506]

2 hours ago, Savage3 said:

There is the problem sir! Take solenoid off the vehicle, bench test.

When power is applied, you should have continuity between terminals.

When no power is supplied, you should not have continuity.

In short, either solenoid is welded or you have constant power in that circuit.

First step, bench test solenoid.

 

I have to go to work Boss. If this doesn't make sense, search you tube for bench testing a solenoid.

 

I'll check back later.

I went end to end and I checked my wiring while I was bored. Everything seemed fine, I didn’t find anything pinched or exposed or anything. This quad sat in a field for a very long time outside so I wouldn’t be surprised to find corroded or damaged electrical bits. Amazingly all the headlight, tail light, buttons, etc all work. 
 

So question. Testing both terminals like in my photo before it should yield NO current while running? Or while off? It’s odd because the starter works when I push the button and I can hear it clicking when I push the button. But I do have voltage running, on or off. I’ll bench test it tomorrow. 
 

I pulled the carb tonight and stripped it down. Noticed worn seals and all that, cleaned the hell out of it and reinstalled. Same low low idle, double checked all my lines and such as well. Definitely will need a rebuild kit or a new carb I think. I changed all my vacuum lines regardless with no change. It does ride around though as long as I’m throttling up though. Ha. 
 

added a video of turning off the quad. Ironically when I took this video it idles perfectly and then konked out when I blipped the throttle. 🙄

[Mech]

So you are still having the problem it won't turn off right ?

And it has a problem with the idling.. right ?

And is there a problem starting too ?

All of that could be caused by the key switch.  That diagram I posted showing the switch for the 160, that's just showing what gets contacted where. It doesn't absolutely mean that there are two sliding contacts for the ignition and kill. It can be that there's one contact and it slides along from shorting the ignition to earth, then onto a live contact and then onto the acc feed contact. If it has lost motion in there it can be not always contacting the acc contact, or going far enough to contact the earth or kill..  I've seen it before with ignition switches. And kill switches.

All the electrical problems can be the switch, and it might cause the erratic idle and then dying as well. The idleing things though might be bad mixture, either by adjustment of air leaks blocked jets etc, or wear on the butterfly shaft if it has one, or play in the slide.

[Mech]

And, if in that picture of the gauge, those are the big starter terminals you are reading over, then that's what we would expect you to get. That would be reading from a live battery lead, to the starter, and the starter as far as that gauge is concerned is a short to earth because the starter draws so much current.  Savage was I think saying to test the two small solenoid wires.

Is the starter working ? You hadn't mentioned a no start.. or did I miss it.

Oh... mybad.. I see you did say the starter is working later on there.. 

[Jd101506]

3 minutes ago, Mech said:

So you are still having the problem it won't turn off right ?

And it has a problem with the idling.. right ?

And is there a problem starting too ?

So right now. The key won’t turn the fourwheeler ‘off’ when the engine is running. It starts fine, and I don’t notice any other weirdness aside from a really low idle and the the key switch not turning it off. I can turn the engine off with the engine kill switch though. 

And you mean the two small wires off the backside of the solenoid? Never tested this before. Is there a way I could rule out the switch?

I ordered a replacement new carb for it so I can ‘rule out’ the seals in the carb. At the very least it’ll isolate it to a vacuum problem or electrical for the low idle. Where are all the grounds on these? I found one on the middle of the frame bolted in, but I didn’t see any others obvious. Was thinking I could clean all the grounds just to start. I’m seeing ignition switches are really inexpensive. 
 

 I just sort of expected that if it was the ignition I would have issues more than the engine turning off. Like, right now my headlight and tail light turn on and off as expected flipping between the third position and second. I left the battery connected overnight and didn’t have any drop in voltage so I know there isn’t a phantom draw anywhere either. 
 

Thank you!! 

 

[Mech]

Savage is normally onto it but I don't think the start circuit is any problem.. He might elaborate though.

I'd unplug the main switch and use the buzzer on the gauge to check that it all switches as it should.. I'm suspecting there's some wear stopping the sliding contacts moving as far as they should, and possibly only not as far as they should in one direction, or dirty contacts on the kill part of it..The sliding bit might be contacting the power ok but not a dirty kill contact, or there might be two sliding contacts and one is dirty of loosing travel.. You'll have to try and figure it with the gauge, unless it comes apart in which case rip into it.

[Savage3]

22 minutes ago, Jd101506 said:

 

Edited July 19, 2023 by Savage3
Incorrect

[Savage3]

I agree with Mech. Its pointing toward switch or wiring issues. I misunderstood, I thought the starter continued to spin when the engine shut off. Sorry bud, my bad.

[Mech]

Ah...

 

[Savage3]

I'm not sure if this will be of any help or not fella's

[Mech]

yeah right.. Switch looks the same.. But the power and kill might be one sliding contact that does both.. or it might be two separate sliding contacts.. 

And that's the way to go with wiring diagrams.. Print them out and use felt pens to colour the wires..  It saves a hell of a lot of finger tracing and doub

[Gwbarm]

I think I would take the switch apart and clean with contact cleaner, and check wires for good connections ,also check for continuity between the wire in the switch and connector.

[Savage3]

7 hours ago, Jd101506 said:

Alright. I finally got my tires and ran it around the yard a bit. This thing is just fun as all get out. Definitely need to address the carb being dirty but it went! After I got back from ruining my lawn, I pulled my multimeter and took this reading: 

 

the solenoid terminals read that off or on, running or not. 

Ok gents, I'm working so go easy on me. This is a problem as I mentioned earlier. 

Sorry, I lost focus.

Those terminals SHOULD NOT have voltage across them unless you are pushing the starter button.

Now, we still have other issues I believe. 

Looks like we will have to test the switches as well.

Can you take a picture of the small terminals on the solenoid?

Thanks 

[Jd101506]

Ok, so its been awhile BUT I have a new keyswitch coming today to test.  I'm going to start there, the key is kinda sh** anyway, so this is a good opportunity to test a few things.  

... But I can't figure out how to remove the headlight.  I can see the bolts holding the ignition plastics on UNDER the light, but is there a slick way these Suzuki headlights pop off?  I don't want to break it removing.  

Since last message I QD contact cleaned ALL the contacts between components and to the frame.  I also got a brand new carb, fuel pump, and replaced the fuel lines.  The quad runs signficantly better, but even after messing around a bit it still runs a little weird and seems to want to stall on occasion still.  Its making me lean more towards the electrical being off somewhere.  I swapped this carb and fuel pump into my 1988 Quadrunner 4x4 and it runs great, so I know the carb and pump are good.  

 

[Mech]

Have you got the service manual Jd.. That will explain how to get the headlight off I'm sure.

I'd wait till the new switch arrives though in case that's all the problems.