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catphe10

86 TRX125 No Spark In Nuetral

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Hello All, I picked up an 1986 TRX125 a couple months ago and I'm finally getting around to fix it up. When I bought it the guy said it could not be in neutral to start, and that it had bad compression. I have already fixed the low compression, but I'm trying to figure out why i cant get spark in neutral. It has spark when in any gear including reverse. When its running it will have spark in neutral but no spark in neutral if its not running. My first thought was the neutral safety switch, but after looking through the manual and seeing how deep id have to tear into the machine to replace I'm hoping for something easier. I'm wondering if it could be the CDI? Or something Else? Anyone have this issue? or other thoughts?
Thanks,

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If it runs I wouldn't think the CDI is the problem. 

 

I have two 85 125's and the plan is to build one good for my kid, but she's 18 months now so haven't been in any big hurry to work on them yet.

 

I'd be curious to see what you find.

 

Did you download the factory service manual yet?  It's in the toolbar at the top of the page.

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Hi catphe10, welcome to ATV Honda!

 

Are the neutral light and the reverse light both working right? The wiring harness all stock with no splices or other mods? The ignition CDI an OEM Honda original part?

 

If so, first thing I would verify is that the reverse & neutral switches electrical connectors have not been swapped? For instance, the neutral switch could be plugged into the wiring harness where the reverse switch should be plugged in... since both of those switches have identical barrel connectors.

 

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Jeepwm69; I do have a copy of the manual. Only reason I thought the CDI is I know that there are a hand full of things it controls. Plus like I stated I really dont want to have to tear into the side of the engine if i dont have to.

 

retro; I have not found any splices or modifications to the wire harness (yet), as far as i can tell The CDI is original. I have already tried the swap on the two wires, when i did this i had no spark at all. No spark in Neutral or any gear. I swapped back and then was back to only no spark in neutral. I can't answer the light question, i did not pay any attention to what the lights where doing / not doing. I will look at it after work.

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Ya, check that the two dash lights are coming on and going off when they should and let us know before we dig any deeper into the electrical.

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So I just checked what the lights are doing, and I'm a little surprised. The green neutral light stays on continuesly. The red reverse light is on when in neutral but will turn off when shifted into any gear. I would guess there has to be some wires crossed somewhere then.

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Yup, you are on to it! Here is the wiring diagram in case ya need it. Keep us posted on what you find out whenever ya can.

 

wiring.png

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So with the reverse light acting like the neutral doesn't that mean the two wires by the reverse lever are wrong? shouldn't they be switched, so the neutral light works as it should?

Which would lead me back to no spark, but a step further towards finding the real wiring problem?

 

I forgot to mention that i also noticed that the Head light is also always on. I flipped each switch high/low and on/off but the light stays on.

I'm thinking that there might be a couple wires crossed in the bundle inside the headlight. Thoughts?

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can you post us sime pics, (many from all angles) and ill go ahead and ask, no rodent damage (wires chewed up) ? 

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_wilson_; What part(s) do you want pictures of? just the wiring? I have not pulled the headlight assembly apart yet so i don't know whats been done in there yet.

I have not found and type of wire issues yet, human or mice. again I'm not very deep into the wiring yet, the only place I've looked is the connections with the Neutral switch bundle above the Reverse lever.

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that's okay, you'd know if it was chewed up, I've seen a bunch of issues due to mice / rodent damage, i was just curious. keep up the work, and let us know what if any wiring issues that look strange. the light staying on all the time got me to thinking, did you ask the previous owner if he, or someone else had messed with the wiring ? 

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12 hours ago, catphe10 said:

I forgot to mention that i also noticed that the Head light is also always on. I flipped each switch high/low and on/off but the light stays on.

I'm thinking that there might be a couple wires crossed in the bundle inside the headlight. Thoughts?

 

That might be a clue! I think at this point I would compare the wire color of every wiring connector on the harness with the wire colors on the factory wiring diagram to make sure that every component is plugged into the right connector. Then test each of the switches in the handlebar switches assembly. Its gotta be something simple.

 

EDIT: Also check the ignition switch per the service manual.

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So I had some time to tear into the wiring this afternoon. When I opened the headlight some obviously was trying to rig stuff to work, there were no cut wires thankfully but half the wires were not connected to anything. So after spending some time figuring out the wires I got it all back together. I have to do some cleaning in the on off headlight switch but once that started working then everything except one thing works as it should.

 

When I connected the neutral and reverse wires at the transmission I again didn't have any spark. So I followed the neutral wire and it goes into the transmission, but when I followed the reverse wire it is grounded to the frame? And not another switch like it shows on the diagram. Is there a reverse switch that wire should go to?? If so where about is it located?

 

Thanks.

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1 hour ago, catphe10 said:

Is there a reverse switch that wire should go to?? If so where about is it located?

 

 

Yup, the reverse switch is located on the sub-transmission cover under a retainer bolt & bracket. Section 10 of the service manual shows where its at, as well as the parts fiche on Partzilla (#20).

 

sub-trans.png

 

20-rev-sw.png

 

Let us know what you find.... its beginning to look like a previous owner was a cobbler?

 

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Ya the previous owner most have been. Do whatever to make it run.

 

As long I I leave the reverse switch wire disconnected everything works perfectly, so untill I can find one I'll just leave it that way.

They plugged the reverse switch hole with a threaded brass plug.

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Ya I haven't been able to find anything online. So I'll end up calling a snowmobile atv/atc salvage yard near me to see if they have one.

Thanks

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catphe10 , wht you looking for

 

My buddy Micheal has a 125 he as been trying to sell me for $200 , no plastics at all , but the rest of the bike is there , the Flea Market is in LaCombe , Louisiana and from what I have been told is the oldest continuously open flea market in the USA , my buddy Andy owns it , and Guiness wants like $800 to verify it , he is a tight wad , but a very cool ex-sailor ,  him and his wife are career Military retired with twin daughter who both just enlisted on their birthday at 18  --- I am pretty sure Micheal  ain't going to sell any parts off it , but would bet it could be had for less than $200 , shipping would be insane ---- how far you away for a road trip 

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Just need a reverse switch otherwise my 125 is all complete.

 

Wish I was closer, I would definitely pick it up. But I'm from northern wisconsin!😂 That would be a 17-18hr one way trip.

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2 hours ago, Fishfiles said:

catphe10 , wht you looking for

 

My buddy Micheal has a 125 he as been trying to sell me for $200 , no plastics at all , but the rest of the bike is there , the Flea Market is in LaCombe , Louisiana and from what I have been told is the oldest continuously open flea market in the USA , my buddy Andy owns it , and Guiness wants like $800 to verify it , he is tight wad , but a very cool ex-sailor ,  him and his wife are career Military retired with twin daughter who both just enlisted on their birthday at 18  --- I am pretty sure Micheal  ain't going to sell any parts off it , but would bet it could be had for less than $200 , shipping would be insane ---- how far you away for a road trip 

Fishfiles;

 

Any chance you or your buddy would be willing to see what the cost of shipping would be?

 

I checked honda restoration but according to their website they don't have what I need.

I have a call in to the salvage year near me but they didn't sound very hopeful.

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I just emailed a fellah on eBay who is selling TRX125 parts about a reverse switch.  I'll let ya know when he responds.

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Four eBay sellers have responded so far and none have that switch.

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Lol, I think it's going to end up being kind of tough to find. But sooner or later one should show up.

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6 hours ago, catphe10 said:

I checked honda restoration but according to their website they don't have what I need.

 

well... i thought it was worth a go. looks like you have a few looking, sure the part will come up soon.... i called JL my old boss, he said has one, but it belongs to a customer, he said he would me let know something next week, i know of another guy, but ... it's very doubtfull, I'll check with him also. 

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