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Discussion Starter · #1 ·
Hello all. I've been handed down my grandfather's 1986 Honda Fourtrax 350. It's been garage kept for it's entire life, only taken out for hunting trips.

I've been working on getting her running. I've dumped the gas, flushed the tank, and rebuilt the carb. I put a clear filter in and see gas making it's way from the pump to the carburetor. After I rebuilt the carb she fired up and ran like a dream. I parked her and the next day, no spark. The fuel pump kicks on if I drain the carb and try to start it.

I've been reading old posts and gathered it's either the CDI or stator/rectifier. I pulled the stator cables and the ohms at 2k read 001 and 002. Nothing to ground. Battery reads 12.5 at off and 11.5 while starter is turning

How can I determine if the CDI is involved too? I don't want to buy expensive parts of it's not needed. Are parts even going to be possible to find?


Thanks for any and all help.
 

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Hey, I am actually trouble shooting this exact same thing, except I am having issues out of my fuel pump too. If I bypass the fuel cut relay it works, but through the ignition it does not. I thought I would share this thread with you, I found it helpful: 1986 TRX 350d. no spark
 

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Discussion Starter · #3 ·
Hey, I am actually trouble shooting this exact same thing, except I am having issues out of my fuel pump too. If I bypass the fuel cut relay it works, but through the ignition it does not. I thought I would share this thread with you, I found it helpful: 1986 TRX 350d. no spark
Thanks! I did come across this post, whats unclear for me is would the fuel pump be called in the ignition sequence of the CDI is broken or in a shut down state?
 

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Hi Gents
I’m not a super smart person on these but I’ve worked on a half dozen. So you know, the 86-87 TRX350A is the only one of the 86-93 TRX350 series with an AC CDI. None of the ignition components on the A model can interchange with the Foreman. It’s a little late in the day but I’ll try to get you started.
First off congratulations on keeping the old tanks alive.
Download the service manual from the link in my signature block below. I know the schematic will be difficult to read so I’ll post up a better copy tomorrow. Read the ignition diagnostics section.When switching on, do you get a neutral light on steady and oil light come on momentarily and then go out.
Only buy OEM parts like CDI—you’ll find these are getting scarce.
I see one of you has performed the continuity and resistance readings on the stator. Also check the pulse generator and exciter coil resistance.
it’s important to ensure all connections are clean as these wires can get chewed or broken.

if you think you’ve done a thorough check of the diagnostics section and think it’s the CDI, try heating it to revive it. Remove CDI and place in oven connector side up, no more than 200F, for about three hours. Let cool completely before you reinstall
 

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Discussion Starter · #5 ·
Hi Gents
I’m not a super smart person on these but I’ve worked on a half dozen. So you know, the 86-87 TRX350A is the only one of the 86-93 TRX350 series with an AC CDI. None of the ignition components on the A model can interchange with the Foreman. It’s a little late in the day but I’ll try to get you started.
First off congratulations on keeping the old tanks alive.
Download the service manual from the link in my signature block below. I know the schematic will be difficult to read so I’ll post up a better copy tomorrow. Read the ignition diagnostics section.When switching on, do you get a neutral light on steady and oil light come on momentarily and then go out.
Only buy OEM parts like CDI—you’ll find these are getting scarce.
I see one of you has performed the continuity and resistance readings on the stator. Also check the pulse generator and exciter coil resistance.
it’s important to ensure all connections are clean as these wires can get chewed or broken.

if you think you’ve done a thorough check of the diagnostics section and think it’s the CDI, try heating it to revive it. Remove CDI and place in oven connector side up, no more than 200F, for about three hours. Let cool completely before you reinstall
Thanks for the info! I'll go through that diagnostic section. I'll be honest, I've never troubleshooted a stator before. I know my way around a multimeter, do my measurements for the stator make sense, and if they do do they read as bad? If that info is in the diagnostic sheet my apologies, I'm going to read it on a PC rather than my phone.

When I turn the bike on I get the neutral light and oil temp for 2 seconds or so. When I hit start quickly, the fuel pump engages and fills the bowl. When I hit start again the starter just cranks and cranks with no spark. I did try ether to verify fuel was not the issue. No even hiccup of spark. I also bypassed the killswitch just to verify that wasn't the issue
 

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Yes BTW your stator readings 18.4 in manual. should be .2 to .1 Ohm at 68F between each yellow wire. No continuity to ground.
 

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Discussion Starter · #8 ·
Yes BTW your stator readings 18.4 in manual. should be .2 to .1 Ohm at 68F between each yellow wire. No continuity to ground.
Thanks for the pics! I'll get the meter out and start measuring everything. It'll have to be this weekend as it's raining all week here.
 
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