2000 Honda TRX450es no start

[Scar 7]

’ve got a 2000 Honda foreman trx450es when I bought it, it was burning oil and I ignored it. Don’t judge me. Anyways it was fine I drove it around for maybe two years blowing smoke everywhere I went. One day while riding it just shut off by itself and would not restart. I thought well the rings finally gave and need a new top end. I rolled it into a building and it’s sat for two years. I’m trying to get it going again. I’ve replaced the top end and all the seals etc adjusted the valves by the book. Rebuilt the carb, charged the battery, changed the spark plug and it has spark, checked all the fuses. Compression is at 80psi. Kill switch is in the correct position. It turns over but doesn’t fire with the button nor the chord, it’s in neutral although the green neutral light isn’t on. I’m lost as to what needs to be checked. Is it timing and is there a way to check it without the front case being pulled? Is it electrical? I attempted to ground a light green and red wire but that just made it do some weird stuff and it stopped trying to turn over (I may have done it incorrectly) but I’m not sure what else to throw at it. I’d like to avoid cracking the case if I don’t need too. I’ve posted in the foreman forum but saw someone say in another post that I could get more help here.
Thanks In advance!

[retro 4,052]

Try pouring a trickle of gas into the spark plug hole and put a new, properly gapped NGK spark plug back in the head. Then try to start it. If it fires up and runs briefly you've got a fuel supply or a carburetion issue. If it doesn't attempt to fire up briefly it's likely that the timing chain is worn out and it's jumped time. Let us know what happens.... and welcome to the forums!

[Scar 7]

It’s got a fresh spark plug that’s been gapped to the manual’s specs. I don’t know that it is an NGK. And a trickle of gas in the spark plug hole is a new one on me, sounds sketchy haha

[retro 4,052]

1 hour ago, Scar said:

And a trickle of gas in the spark plug hole is a new one on me, sounds sketchy haha

 

Well you claim that it has spark and compression - so that leaves you with a possible fuel issue, or a possible valve timing or ignition timing issue, preventing the motor from starting. By adding a small amount of gas to the cylinder you are providing the necessary amount of fuel to make it run briefly. As an alternative you can shoot a short blast of Starting fluid into the intake after removing the air filter. Pick your poison....

[retro 4,052]

If you suspect that the cylinder may be dry of lubricating oil (due to excessive cranking since the top end was assembled) then you can add a bit of 2-stroke oil to your primer gas that you pour into the cylinder. Chainsaw premix gas will work OK if ya got a can mixed up and handy.

[Scar 7]

I’ll give it a try in a day or two when I can get free’d up to mess with it. Thanks retro. In the mean time can you tell me anything about the neutral safety switch? Is that a possibility? When I cut the light green and red stripe wire I just jump one of the ends to the negative terminal? Which end? And do I do anything with the other end?

[retro 4,052]

The gear position switch controls the Neutral light. Do not cut any wires... and let us know if there are any cut or broken wiring on it.

 

You said the neutral light is not working, but the motor cranks over with the starter and the ignition produces spark, correct? If that's the case then the gear position switch is functional and is providing the starter solenoid and the ignition with negative grounds through the Light Green/Red stripe wire. So that indicates that the neutral light is not working or not getting it's ground through the Light Green/Red stripe wire. You'd test for that ground at the harness connector for the Display meter.

 

Are all of the other gears being displayed on the screen of the meter?

 

Does the shift motor shift through gears normally while you are rocking the Foreman back and forth?

[retro 4,052]

I should have mentioned.... pour only about 1/4 ounce of gas into the cylinder through the spark plug hole. If you pour in too much gas the spark plug will get too wet to produce spark and the motor may not attempt to start. If the spark plug appears to be wet when you remove it that means it probably has too much fuel in the cylinder already. In that case crank the motor over with the starter for a few seconds while the spark plug is out (and grounded on the head) to clear and dry out the cylinder. You can dry off the spark plug by flushing the end of it with rubbing alcohol then allow the alcohol to evaporate for a couple minutes. The spark plug should be dry when you reinstall it.

 

After you put 1/4 ounce of gas in the cylinder and put the plug back in, slightly open the throttle a bit while you try to start it.... to give the motor some extra air. It should fire and run for a second or two.

[Scar 7]

9 hours ago, retro said:

You said the neutral light is not working, but the motor cranks over with the starter and the ignition produces spark, correct? 

 

Are all of the other gears being displayed on the screen of the meter?

 

Does the shift motor shift through gears normally while you are rocking the Foreman back and forth?

yes that’s correct

 

i did fail to mention that it shifts through all the gears but only displays R,N,1,-,-,-,5. Red light comes on in reverse.

 

I’d like to add that I’m more mechanically inclined. Electronics/wiring is not my forte.

 

Edited October 12, 2023 by Scar
Adding comment

[Fishfiles 20,145]

1 hour ago, Scar said:

yes that’s correct

 

i did fail to mention that it shifts through all the gears but only displays R,N,1,-,-,-,5. Red light comes on in reverse.

 

I’d like to add that I’m more mechanically inclined. Electronics/wiring is not my forte.

 

 

Might just be  throwing something on the wall to see if it will stick 

 

 

I have had a couple of 450s both foot shift , I was told so I did not need the display screen to run them ,  it  must be true cause I don't , not  sure if a ES is the same , I think I read before that the ES  requires some kind of signal of gear placement to start ------  we have a guy here that knows them displays well @alatv

[Scar 7]

Maybe I’ve just done too much reading on forums and have one giant brain fart that kept me from realizing what I was being told.
So if there is spark the motor should be firing.  unless it’s fuel or timing. 
the no neutral light/display issue is completely separate because I have spark. I’d love to get that fixed as well but if it’s not preventing the motor from running it’ll go on the back burner for now.

I’ve bought a new NGK DPR7ea9 and some starter fluid. I’ll be back with results once I give that a try, thanks guys 

[Fishfiles 20,145]

What made  confusion to me  , was you calling " starting up " as firing , being a heavy equipment mechanic all my life , I have heard people say the term " getting it fired up " meaning the  starting of an engine >>> I personally always use the terms fire and spark as the same thing ,  that lightning bolt of energy that will make you go ouch 

 

For a gas motor to run , you need  fuel , spark , compression and proper timing 

 

Be careful with that starting fluid , go lite , it can bend a rod  >>>>  Retro was telling how to do it with out using the fluid 

 

[retro 4,052]

1 hour ago, Scar said:

Maybe I’ve just done too much reading on forums and have one giant brain fart that kept me from realizing what I was being told.
So if there is spark the motor should be firing.  unless it’s fuel or timing. 
the no neutral light/display issue is completely separate because I have spark. I’d love to get that fixed as well but if it’s not preventing the motor from running it’ll go on the back burner for now.

I’ve bought a new NGK DPR7ea9 and some starter fluid. I’ll be back with results once I give that a try, thanks guys 

 

You might be right if you've come across conflicting info on forums. There's a lot of troubleshooters out there shooting their arrows in the dark. :)

 

Yes, if there is spark, compression and fuel the motor should run - unless the valve timing is off, or the ignition timing is off, or a 3rd possibility in your case; the exhaust system is plugged up with oily carbon deposits.

 

Yes, the no neutral light condition by itself cannot prevent the motor from running.... provided you have spark and the starter works. If you did not have spark and the starter did not crank the motor, then the first suspect would be a faulty gear position switch, because that switch provides the negative ground circuits (through the Light Green/Red stripe wire) to complete both the ignition system circuit, and the starter solenoid circuit, as well as the neutral light and the "N" indicator on the display meter. If that switch were not providing a ground (an open circuit condition) while in neutral, the starter would not crank and there would be no spark and no neutral indicators on the display. The machine will operate just fine without the display plugged in, so for the time being we can focus on the no-start condition, then dive into the neutral light/meter issue later.

 

However, a gear position switch can fail in two ways -- either in open circuit conditions which is loosely explained above, or in a closed circuit condition (shorted) when it shouldn't be. In a prior post you mentioned that the gear indicator in the display meter shows only R,N,1,-,-,-,5 -- which can be a symptom of a faulty meter -- or possibly is a symptom of a shorted (closed condition) gear position switch (closed circuit condition in every gear position, providing a ground in gears that it's not supposed to). The reason for that line of thinking is the fact that on a 450 Foreman ES, the gear position switch must only provide grounds when the transmission is shifted into reverse, neutral, first, and fifth gears. The display meter calculates which one of the second, third, and fourth gears that the transmission is shifted into by counting the ES shifts up and down between the first and fifth gears.

 

I hope these explanations are a bit clearer than mud.... I'm a poor communicator when typing stuff. But I try to provide enough info to folks so that they'll understand how the stuff works that they're working on.... our work is easy once we got a complete picture in our mind.... and since this thread might help many others that find it later on, I tend to rant on a bit too much about stuff. Just ignore me when I explain things you already know. :)

[Scar 7]

Retro it ran for a second or two with the gas in the plug hole.
You should have seen my face. 

[Fishfiles 20,145]

I would start checking fuel flow , open the bowl drain screw to see if the bowl is filling up , if there is fuel there it could be the float needle is stuck  , if there is no fuel there I would take the hose off the petcock and check for flow there , could be clogged in the petcock or the tank screen ---- could be bad fuel , full of water , before doing the bowl drain , get a clean pan under the drain hole and catch what comes out and look for water , if the bike sat up for a while , chances are good that there was condensation in the tank , which would go to the bottom of the tank and into the carb 

 

 

[Scar 7]

I rebuilt the carb added a new choke cable and emptied my gas tank and sloshed it around with some high test.. never suspected it to be the issue. I’m guessing I did something wrong in the rebuild. gonna go back through it all tomorrow morning hopefully. I did notice a tiny bit of fuel on the opening of the carb on the air filter side. Is that a specific issue or was it just from me plunging it too much to pull fuel in or something?

[Fishfiles 20,145]

Is fuel getting to the carb ?

 

I am remembering the 450 will not flow fuel  well unless the hose is flat , along that plastic heat shield , if it is pushed up it doesn't flow to the carb , did you add a filter and it is pushing up on the hose 

 

When you cleaned the carb did you , disassemble it and soak it in a gallon can of Carb cleaner and then blow all ports with compressed air or was it just a spray off with a can of aerosol cleaner 

[Scar 7]

I’ll check that hose tomorrow too before I begin pulling the carb back apart.

I just sprayed all the parts and ports really good with carb cleaner and replaced the parts that came in the new kit.

[Scar 7]

Well it was a port in the carb. I must have over looked it when I was doing the rebuild. But when I found it I could see it was clogged. Rhode it around in second gear for a bit after getting the idle right. Noticed a little backfiring on deceleration, but I had that issue I believe that last time it ran. Just seems a little worse now. is this from the air/fuel mixture screw?

Edited October 13, 2023 by Scar
Edit

[shadetree 5,910]

3 hours ago, Scar said:

Well it was a port in the carb. I must have over looked it when I was doing the rebuild. But when I found it I could see it was clogged. Rhode it around in second gear for a bit after getting the idle right. Noticed a little backfiring on deceleration, but I had that issue I believe that last time it ran. Just seems a little worse now. is this from the air/fuel mixture screw?

yes..air/fuel mixture is not 100% correct.

[Scar 7]

That’s what I figured. Ordered a tachometer 👍

 

[retro 4,052]

On 10/12/2023 at 5:57 PM, Scar said:

I rebuilt the carb added a new choke cable and emptied my gas tank and sloshed it around with some high test.. never suspected it to be the issue.

 

6 hours ago, Scar said:

Well it was a port in the carb. I must have over looked it when I was doing the rebuild. But when I found it I could see it was clogged. Rhode it around in second gear for a bit after getting the idle right. Noticed a little backfiring on deceleration, but I had that issue I believe that last time it ran. Just seems a little worse now. is this from the air/fuel mixture screw?

 

Thanks for sharing more details! This helps a lot.

 

First question: Was the carb kit you put in the carb a genuine Shindy (brand) kit? The reason I ask is because no other aftermarket carb kit brand have ever worked on a Honda ATV. They're all chinese knockoffs with inferior (incorrect) parts that destroy the functions of the carb. If the kit you put in your 450 carb was not OEM or Shindy, then you'll have to put all of the original metal parts back in the carb.

 

Assuming that you have good non-china parts in the carb, and the fact that the motor backfires and behaves similar to it's behavior before the teardown, it's highly likely that the only issue remaining with it is a still dirty/plugged carb jet or passage. No amount of adjustments will ever solve those kind of problems.

 

Sometimes a clog can be a bugger to get out. Let us know if you can't get the carb clean so we can help.

 

Also make sure that you follow the service manual steps in the Fuel system section when reassembling the carb to insure that it's set up right.

 

Remaining true to my habit, here is some more info you may not ever need. :)

The service manual for your 450 (and most other Honda ATVs) can be downloaded from the link in the menubar at the top of every page. Here is a link that will save you a few clicks.... the 1st manual of the two that are listed is the one that you want.

https://drive.google.com/drive/folders/15eWwngQ5SdlsIfbgpm5ZJWJYBYx3vJ7s

 

 

 

 

[retro 4,052]

6 hours ago, Scar said:

Noticed a little backfiring on deceleration, but I had that issue I believe that last time it ran.

 

Also I forgot to mention that a leak in the exhaust system can cause backfiring since a leak allows air to enter to support residual fuel combustion inside the pipes. But more commonly it's caused by a lean running motor, which a clogged carb condition creates.

[Scar 7]

11 hours ago, retro said:

They're all chinese knockoffs with inferior (incorrect) parts that destroy the functions of the carb. If the kit you put in your 450 carb was not OEM or Shindy, then you'll have to put all of the original metal parts back in the carb.

Haha uuhhh well that’s good to know. 
 

It’s definitely not clogged anymore I literally saw the clog and watched what ever it was shoot out of the port when I sprayed it for a few seconds. I believe it was just behind the air cut off valve pictured above. I did a very thorough cleaning this second time.

I am 100% rocking an Amazon special carb kit that had Chinese all over the package. 
I’ll get it swapped out for shindy considering I trashed all the old parts already. 
 

Tachometer is on the way so I can get it adjusted correctly as well. 

thanks for all the help guys! I’ll update on the backfiring once I get the new kit and tach 
 

[retro 4,052]

1 hour ago, Scar said:

It’s definitely not clogged anymore I literally saw the clog and watched what ever it was shoot out of the port when I sprayed it for a few seconds. I believe it was just behind the air cut off valve pictured above.

 

When the Air Cutoff valve is regulating air through the port correctly at all times, it's function prevents backfiring on deceleration.

So make sure that the object that you saw fly out of the air cutoff port was not the brass orifice (which is sandwiched between the valve and the carb body when the valve is installed), or the sealing o-ring that fits over the end of that orifice and seals the orifice within the port. If any of those parts are missing (the brass orifice or one of the o-rings) the port will suck air full time which will allow air to be introduced into the idle circuit on deceleration, which can cause residual idle circuit fuel to ignite inside the exhaust and create an occasional backfire.

 

 

A Shindy kit will work as good as OEM in most cases. However, if you ever put a Shindy kit inside a Honda carb in the future, cleaning and reusing the original OEM brass jets is the best practice IF you can get them perfectly clean -- because OEM (Keihin) jets are made to meet tighter tolerances than aftermarket parts are. The only exception that I ever make is when I can see wear along the tapered length of the Jet Needle, and/or see some small amount of wear inside the brass Needle jet. Once those two parts begin to wear into each other (caused by the movement of the Jet Neddle with the throttle) they should be replaced with the Shindy kit parts. If they're in perfect condition reuse them.

 

Also never throw away any of the OEM carb parts that you replace. Keep them at least until you are satisfied that the new parts inside the carb are working as they should. I never toss those parts out because I feel that OEM parts are more valuable than aftermarket parts. I won't even replace an OEM float valve with one from a kit unless the viton rubber tapered tip is worn out beyond the point that I cannot restore it in 30 seconds of effort. OEM is the best stuff, always.

 

OK, it's that time in this post to again provide some more info that you may already know.... :)

Do not ever try to replace any part on a Honda ATV with aftermarket cheap china knockoffs purchased from any source (Shindy kits do work because they are Japanese) . Everything china is garbage, none of it ever works and in some cases china parts fry perfectly good (expensive) OEM parts the moment you plug them in. Use OEM Honda parts with OEM part numbers only. Buy just once... and you'll cry just once as they say.... This is the first thing most inexperienced Honda folks learn when they join us. Trust us, there are no exceptions to this fact, we've seen the carnage a gazillion times over a gazillion years now it seems, and it still makes us feel really bad when we have to welcome a new member with such bad news...

 

3 hours ago, Scar said:

thanks for all the help guys! I’ll update on the backfiring once I get the new kit and tach 

 

Awesome! Updates are what we live for here! Thanks and looking forward to hear more from ya Scar!