86-89 350 Foreman differences

23309 Views 41 Replies 12 Participants Last post by SEOHIO, Dec 14, 2021

Jeepwm69

Discussion Starter · Jan 23, 2018

So I know on the 300's the CDI on the first gens are different than the CDI's on the 2nd and 3rd gens (IIRC, the 3rd gen CDI's are the same as the 350 Ranchers)

What about the 350D? I have an 86, 87, 88, 89, and two more in the shop on the farm that I'm not sure of the year without looking. The CDI part numbers are all similar but not exactly the same. Are the interchangeable?

Any other differences are there as far as part compatibility?

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LBZ_Duramax

· #2 · Jan 23, 2018

I believe the 86 is the different one. I know that the 86 has to have a hot battery for the CDI to fire

Goober

· #3 · Jan 23, 2018

In the back of the service manual psome differences are explained sorry I can’t Photo it for ya right now. There are three systems that I recall as requiring separate components
86 AC-CDI
87 DC-CDI
After 87 Revolution Research line page 17-6

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retro

· #4 · Jan 24, 2018

These questions come up from time to time and its hard to remember everything, but electrically (wiring harnesses, switches, ignition components) it goes like this:

86-89 (thru 93 in Canada) all years and models can use the same spark plug, Ign coil, pulse generator and battery. But thats it.

86 & 87 TRX350 Fourtrax models have an AC-CDI ignition (a battery is not required for spark) so all ignition & electrical parts are interchangeable between those two years and thats it, with the exception of the spark plug, Ign coil, pulse generator and battery as mentioned above.

87 TRX350D Fourtrax Foreman is one of a kind. It has a unique DC-CDI ignition and all switches, wiring harness, fuse box, stator and other ignition components fit that year and model only, with the exception of the spark plug, Ign coil, pulse generator and battery as mentioned above.

88-89 (thru 93 in Canada) TRX350D Fourtrax Foreman have a revised DC-CDI ignition (added a "Revolution Research Line" circuit in the CDI) and all ignition components, switches, harness, fuse box, stator & other electrical components can be interchanged among those years only, with the exception of the spark plug, Ign coil, pulse generator and battery as mentioned above.

There were many mechanical differences and changes made among those models and years too. Anyone interested in more confusion...?

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Duck0fDeath

· #5 · Jan 24, 2018

Thanks for that detailed explanation Retro. That will help a lot in my parts search. I don't like the fact that I can only use ignition system parts off another 87 if I can't find new. At least I'm less likely to get the wrong part like I almost did on some NOS I found on ebay where the seller claimed his brand new ignition switch worked on all models from 86-89.

retro

· #6 · Jan 24, 2018

Yeah Duck, gotta be careful buying parts on the frau-ction site. Some sellers don't know any better... and some know better but are dishonest and don't care. The frau-ction company policies and practices coddle and protect them (in the image of the site owners) so you're on your own... Remember, 1987 TRX350D Fourtrax Foreman part numbers only... when sourcing electrical parts for your bike.

I found everything I needed for mine OK (and cheaply!), just gotta be patient and learn how to identify parts by their photos. Keep a smile on and let me know if I can help!

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Goober

· #7 · Jan 24, 2018

Dang thanks Retro. I bought a CDI brand new for an 87 Fourtrax thinking and I could use it as a spare for my 86. And then read somewhere I couldn’t. I should check that part number before I do a happy dance.

retro

· #8 · Jan 24, 2018

You should be fine with that CDI Goober. 86 & 87 Fourtrax TRX350 use the same AC-CDI ignition system.

https://www.partzilla.com/product/honda/30410-HA7-672

It wasn't until the first Honda Foreman (TRX350D) was introduced in 87 that the shell game began...

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Jeepwm69

Discussion Starter · #9 · Jan 24, 2018

Yikes. This is going to create a lot of confusion selling parts. I don't want to sell anything to someone that might not work on their machine.

How does one tell the difference in an 87 with the 86 style CDI and an 87 with the one year specific stuff?

I've got an 86 (the one I'm going to get running for this kid)
His 87 which I will likely part out
An 88 that is about 60% complete
An 89 that is about 80% complete

and two more at the farm shop that I'm not sure what years they are. One of those is about 80% complete and the other one is a frame with a front end and a few other odds and ends on it.

So even ignition switches are different? I noticed the switch on the 86 I just bought (guy said he used the 88 switch on it) had 5 wires on the wheeler, and only 4 on the switch. That said with 12V it lit up the neutral lights, burped the fuel pump, and tried to fire.

Pink
Red with white x2
black
green were the wires on the wheeler IIRC. The ignition switch didn't have a green wire

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retro

· #10 · Jan 24, 2018 (Edited)

All of the TRX350 Fourtrax models (ALL 1986 350s + 87 TRX350 only) use the same AC-CDI ignition/electrical system, so all parts interchange among those.

In 87 Honda offered both the TRX350 Fourtrax AND the 1st year TRX350D Foreman. Parts will not interchange between those two models. The 1st year TRX350D Foreman was one of a kind.

88 and up 350s were all TRX350D Foremans (The TRX350 Fourtrax ended production in 87) and all parts interchange from 88 up.

So there were three ignition/electrical systems versions in total:

1) 86 & 87 TRX350 Fourtrax
2) 87 TRX350D Foreman
3) 88 and up TRX350D Foreman

An 88 (DC-CDI) ignition switch will not interchange on any 86 or 87 bike. All 86 bikes have AC-CDI (no battery required for ignition, just kick it and it will spark) so shutting the ignition switch off (or the Kill switch!) on the 86 & 87 TRX350 grounds the ignition out. The opposite is true (turning a switch off opens the circuit) for all TRX350D DC-CDI ignitions.

Its not that confusing as long as you pay attention to the actual model number.... whether its a TRX350 (which were offered for only two years) or a TRX350D.

Also to answer your question about ID-ing an 87 Foreman CDI...? It was one of a kind... made by Shindengen and says so on the casing. I can take some pics if you'd like?

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Jeepwm69

Discussion Starter · #11 · Jan 24, 2018

retro said:
All of the TRX350 Fourtrax models (ALL 1986 350s + 87 TRX350 only) use the same AC-CDI ignition/electrical system, so all parts interchange among those.

In 87 Honda offered both the TRX350 Fourtrax AND the 1st year TRX350D Foreman. Parts will not interchange between those two models. The 1st year TRX350D Foreman was one of a kind.

88 and up 350s were all TRX350D Foremans (The TRX350 Fourtrax ended production in 87) and all parts interchange from 88 up.

So there were three ignition/electrical systems versions in total:

1) 86 & 87 TRX350 Fourtrax
2) 87 TRX350D Foreman
3) 88 and up TRX350D Foreman

An 88 (DC-CDI) ignition switch will not interchange on any 86 or 87 bike. All 86 bikes have AC-CDI (no battery required for ignition, just kick it and it will spark) so shutting the ignition switch off (or the Kill switch!) on the 86 & 87 TRX350 grounds the ignition out. The opposite is true (turning a switch off opens the circuit) for all TRX350D DC-CDI ignitions.

Its not that confusing as long as you pay attention to the actual model number.... whether its a TRX350 (which were offered for only two years) or a TRX350D.

Also to answer your question about ID-ing an 87 Foreman CDI...? It was one of a kind... made by Shindengen and says so on the casing. I can take some pics if you'd like?

Hmmmm.. The 89 I have was bought by a friend. The prior owner said it didn't have spark.

I pulled the rear end and put it in his 300, and he said to keep/part the rest.

I looked at the CDI on it and it said Shindengen.....wonder if a prior owner put the wrong CDI on it and that's why it won't fire.

PatrickB

· #12 · Jan 24, 2018

Awesome info retro, very informative as well!

Sent from my SM-G550T1 using Tapatalk

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retro

· #13 · Jan 24, 2018

Jeepwm69 said:
Hmmmm.. The 89 I have was bought by a friend. The prior owner said it didn't have spark.

I pulled the rear end and put it in his 300, and he said to keep/part the rest.

I looked at the CDI on it and it said Shindengen.....wonder if a prior owner put the wrong CDI on it and that's why it won't fire.

I'm not sure about that... Shindengen might have made all of the CDIs for the Foremans from 87 up...? I'd assume that the CDI that was in the 89 is correct and just do a basic diagnosis on the rest of that ignition system. A bad ignition switch or a bad kill switch were the most common parts to die on those. Sometimes the main 30 amp fuse blows too.

If the fuel pump is working while cranking it over with the starter, its probably a bad coil or bad pulse gen... assuming the harness plugs are all in decent shape.

Jeepwm69

Discussion Starter · #14 · Jan 25, 2018

I had time to briefly check them all again yesterday.

The 87 is a non-D model (TRX350) so that's good. That means the parts will interchange with the 86 I'm trying to get running.

The 87 D model specifies Shindengen on the parts schematic whereas the others do not, but as you say, that doesn't necessarily mean anything for other years.

https://www.partzilla.com/product/honda/30410-HA7-751?ref=8023f93ab176944bf398d8d5a2829c0a21a1cc15

I have an 88 CDI so I can compare the two (at least visually) and see if they're the same.

Thanks for all your help Retro. These old tanks are complicated when it comes to year-to-year differences.

I looked at the machines on the farm yesterday too, so the final talley is

1 86 complete, almost running
1 86 frame with a front end a few other minor bits
1 87 TRX350 non-D model, so same as the 86's
2 88 350D's
1 89 350D

At this point I'm thinking get the 86 running and off to the kid, and maybe try to fix the 89 or one of the 88's using the others as donors, then sell parts.

Might just get the 86 running for the kids and sell the rest. That would be the smart move, but I have to want to "save" all these old Hondas.....lol

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retro

· #15 · Jan 25, 2018

Sounds like a good plan! If you can get two good running bikes out of those you might make your money back (with a profit?) quicker and still have a bunch of valuable parts left that might sell slower... but they'd all sell eventually. That is, unless you (or your wife) become a tank resto/collecto fan...

If you end up with any loose motor parts that you wanna get rid of when the smoke has cleared, let me know. I'll be scrounging for spare valve train parts and/or a head for sure, at some point.

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Jeepwm69

Discussion Starter · #16 · Jan 25, 2018

retro said:
Sounds like a good plan! If you can get two good running bikes out of those you might make your money back (with a profit?) quicker and still have a bunch of valuable parts left that might sell slower... but they'd all sell eventually. That is, unless you (or your wife) become a tank resto/collecto fan...

If you end up with any loose motor parts that you wanna get rid of when the smoke has cleared, let me know. I'll be scrounging for spare valve train parts and/or a head for sure, at some point.

I'm sure we can work something out.

I'll have a couple of motors at least, and don't think there's a market around here to sell a whole, non running motor, so I'll be stripping them down.

I guess the heads and top ends are still in demand from the 300 hot-rodders or something judging by ebay prices.

Part prices for these things are all over the place. Some stuff is ridiculously expensive and some stuff is dirt cheap.

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retro

· #17 · Jan 25, 2018

Yeah, good heads are still in demand. Prices are all over the place too like you said. Some of those guys on fLeebay have had their stuff for sale for a year or more, while other guys seem to move their parts more easily. Let me know if you run across any parts you need while putting those bikes together, in case I already have good spares stashed away... I'm less than 3 miles from the post office and ship a lot of flat-rate priority boxes out anyway.

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Jeepwm69

Discussion Starter · #18 · Jan 26, 2018

Yesterday I went out to look for a few odds and ends for Ducks. I pulled the CDI off of the 88 in my yard and it looks to be the same as the 89, so looks like the 88-89 are the Shindengen made too.

Hooked jumper cables to the 89 just to see if it would do anything. Fuel gauge lit up, but I got nothing in the way of dash lights.

Hooked cables up to the kids 87 and the top light works, starter works, so had someone put a top end on it back when it was torn down it probably would have been good to go. As it is, it's been sitting for, if I had to guess, 5+ years with no top end on it, so the engine's going to have to be torn down and cleaned out to be any good. The engine has been covered so I don't think it's full of water, but with the cylinder hole open dust and grit in the air has coated the piston, rod, timing chain and guides etc, so no way I would just slap a new top end on it.

retro

· #19 · Jan 26, 2018

You've got a complete motor in the 87 that should plug & play... swapping motors would be a lot cheaper and quicker than tearing down the 86 with the topend missing.

It sounds like your 86 might be a runner that could be sold complete? Your 88 & 89s might easily make at least one more complete running bike too?

Its great to have options.

Jeepwm69

Discussion Starter · #20 · Jan 27, 2018

The 87 is the kids bike with top end off. 86 I just bought, and motor tries to run.

But yeah, I have a few choices I can make with all these parts rigs

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