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About two years ago I was given our family wheeler an 87 350 fourtrax. It was in fid shape but did not run very well. A few minor things and a new gas tank and it is turn key. This summer I happened to chance upon a 86 350trx I scored for $350. Mostly thinking for parts because the engine was seized.
After a week of patience I was able to get it to turn over and another week I got it running. Idling and starting very well. The carb was over flowing with gas and the tank was disgusting. So I took them both of the bike and cleaned them. However after reinstalling and trying to start. I am not getting any spark or power to the fuel pump. What am I missing? Starter turns, lights work, fuses are all brand new, new fuel pump, fuel cut relay test fine, and that's where I am.
Please help.
 

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OEM fuel pump?
I'm thinking you discoed a wire somewhere
Follow the ignition troubleshooting technique in the manual.
On a unit in unknown condition may also be a CDI exciter coil or stator u name it so troubleshooting steps very important
 

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The 86 was running before you cleaned the carb & tank and you are working on the 86 only, not the 87 right?

You have not borrowed any parts from the 87 and put them on the 86, right? The reason I ask is those two have entirely different ignition systems... parts won't interchange... from ignition switches & kill switches, CDIs, stators... you name it, they all differ from 86 to 87.

Did you put a new OEM Honda fuel pump on your 86 or was it an aftermarket pump? Why did you replace the pump?

Did you replace anything else other than the fuel pump on the 86?

Welcome to the forums! And thanks for those pics of your TRX350s!
 

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Discussion Starter #5
Thank you

I am horrible with wiring and have taught myself most things. I have followed the writing diagram tho and I have been leaning towards testing the cdi unit. So thank you goober for the confirmation.
I have not switched any components from the 87 to the 86 because I noticed the wiring diagrams were different.

Guess Im going to study up on my electronic testing skills.
 

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Discussion Starter #6
Everything is working when it comes to lights. The kill switch was working when it ran. This bike was driven into a river by previous owner. So it's been a lot of work to get it to where it is now and I wouldn't be surprised if all the electrical components need replacing. Lol
 

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Glad to see your success and determination in restoring the old beast. Idk if you can actually test the CDI you can only check the function of other components that can also inhibit ignition

Will it try to run if you squirt a bit of starting fluid in the carb? Only a bit! It's hard on the engine and could start a fire. If it runs but quits immediately I'd be inclined to swap the CDI.
@retro @shadetree or others Is it possible to power the fuel pump directly to ensure it works?
 

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Yes, you can power the fuel pump from the battery to test it. You can also jump the fuel cutoff relay and the pump should run with the key switch on. The pump has nothing to do with a no-spark issue though.

I am going to put together a step by step diag for you... This will take some time because I have to leap from section to section in the FSM to get all the relevant info. Hang in there john_e_gardner... be back in a bit with some goodies. :)

EDIT:
First thing you can do is unplug every connector on the wiring harnesses and look for corrosion. Plug them back in and make sure they each snap together snugly. Also, remove clean and reconnect the ground wires connection where it comes out of the main wiring harness and bolts onto the upper-right frame rail next to the airbox & seat bracket.

Be back in a bit...
 

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I am going to post these individually and wait until you have completed each test (or series of tests) before moving on...

You will need a decent multimeter for these tests. If you don't have a multimeter let us know... we can alter our tactics for that.

Unplug the CDI (it is located under the right-front fender in the right-front corner of the upper frame.) and check continuity and ohms resistance between color coded wires in the wiring harness-side of that plug according to this chart:



This harness plug has all-in-one access to each of the ignition components we are interested in, so hopefully this will save us some time. Let us know how each component measures and ask as many questions as you'd like. :)

I'll wait until these are done before continuing.
 

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I do not have the best multimeter. And just read up on testing continuity and ohms. If i tested correctly I did not get a reading in the first 2 test. The third only read .3 ohms and the last two test for continuity read correctly.
 

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Okie dokie, these next tests move us closer to the components... if we find everything to be in order here, we can suspect the wiring harness is at fault:



Let us know what you learn from these tests...
 

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After a little more studying and getting to know my multimeter I feel a little more comfortable with my readings. I retested the DCI unit and found that my initial tests were wrong and only the alternator was not reading. And continued checking the components down the line and these readings also confirmed no ohm reading from the alternator. Ill check for bad wires going down to the alternator later. Kids are calling for dinner.
 

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Discussion Starter #13
It does not appear to have any loose or broken wires. I pealed the protective sheath back a few inches to check the wire sheaths and they look and feel like new. Surprised not dry and brittle. ANY suggestions before opening up the stator
 

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So, you got nothing between the Bl/R wire coming from the stator & motor ground? That indicates the left side cover may have to come off for a stator replacement. Before jumping into that though, lets go ahead and check the charging windings in that stator:




Also, since you are peeling the sheath back anyway... before you begin to take that left side cover off, peel the outer sheath away from the stator harness where it exits the top of the cover. There is a rubber grommet there... just wondering if the harness clamp bolt was taken off the motor by someone in the past and the Bl/R wire flopped around and broke where it goes through the grommet...? You can learn more about that possibility after that cover is off too... you'll be checking for continuity from the exciter winding to the harness plug in case that wire went bad... and stator is still good. $ave $ome coin if thats the case. :)
 

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Discussion Starter #16
I measured the connector and everything is correct. I cannot expose the bl/red wire easily without removing parts. However the outer protective sheath looks undamaged.
 

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If that Bl/R wire measures open to motor ground then yanking the left side cover is next. You may lose some motor oil yanking that cover off... Worse case you'll need a replacement 86 TRX350 stator. Best case you'll need to solder the wire. Keep us updated if ya can...
 

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Discussion Starter #18
So I pulled the stator apart and quickly found out what the problem was. the previous owner had tried to start the engine using the starter when it was seized and stripped the reduction gear sending shrapnel into the stator adhering to the magnets and destroying the stator. Ordering a new one. Ill keep everyone posted.
 

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Arghh... Thats gotta hurt. I'd be wondering whether the flywheel & one-way starter clutch & driven gear are alright behind that flywheel...?

Were you able to account for all/most of the busted off pieces? There is a big oil drain back into the cases just to the rear of the flywheel and if memory serves me today, I think the end of the balance shaft & bearing is open too. I'd be in there with a 1/2" Neodymium magnet cube collecting all that garbage....

Question: Will you need to take the right side cover off for any reason? Just thinking about what kind of trash might be collecting under the oil pump pickup screen...
 
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