1987 Honda TRX350D

15822 Views 156 Replies 9 Participants Last post by Goober, Oct 31, 2020

SnapTech

Discussion Starter · Oct 12, 2018

Hi all,
First post. Just got a 87 TRX350D for free from a guy who was gonna junk it. It hasn't been run for a couple years so wasn't disappointed when it didn't start, no spark. Took the CDI out and threw it in the freezer over night and reinstalled the next day. It started. WOOHOO! I let it run for about 15 min. At first it blew a little smoke but that stopped after a couple min and purred away. As it was running I looked it over and saw it was leaking oil between the head and the cover. Shut it off, then it wouldn't restart. No spark. CDI bad. Ordered a new one. While waiting for parts, took head cover off and no seal. Chain was tight. Checked valve lash before taking cover off and they were all in spec. Put the cover back on and rechecked lash, all good. Installed new CDI and it started right up, but is blowing smoke like crazy. What did I do wrong? It wasn't blowing smoke anywhere near what it's doing now.

1 - 20 of 157 Posts

Goober

· #10 · Oct 13, 2018

Whattaya mean new carb?

You need to rebuild the OEM QA03A.

You might be running overly rich.

Is your plug oily or sooty?

Need a compression check.

Goober

· #29 · Mar 14, 2020

Lowall said:
Do you have a Forum to English dictionary? What is the CDI?

Lol it’s the ignition controller
Download the service manual and parts links in my signature block below
Look for TRX350 Foreman

Goober

· #30 · Mar 15, 2020

Bump for @Lowall

Goober

· #33 · Mar 24, 2020

You can first download the service manual and parts links in my signature block below.
One of those fuzes might be a spare I think there are clips for spares on either side of the fuze block; see mine is an 86, has four fuses and two spares.

The oil temp light should come on momentarily and then go out. The neutral light has to be on steady or it won’t crank. Check the gear switch harness connections behind the right side cover and especially behind the cover behind the foot brake. My harness connections were bare and broken.

you can get a used handlebar switch and harnesses but they have to be from a Foreman, not the base model Fourtrax.the schematic does show the logic for each switch in the margins. Fourtrax kill switch is normally open and grounded when set to off; Foreman is opposite

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Goober

· #39 · Mar 27, 2020

It’s easier to inspect wires with the fenders off.
“But now when I plug in the wires to the neutral/reverse switches and turn on the key, the oil temp light stays on and the fan turns on”
The above tells me your neutral wire might be swapped with your oil switch wire?

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Goober

· #42 · Mar 29, 2020

Oh no. You’re gonna want another main harness. I bought one last year for $65–here’s a pic after I completely rewrapped it

you’ll have to make sure it’s for an 87 Foreman
32100-HA7-750

rover.ebay.com

T1138 1987 87 HONDA FOREMAN TRX 350 4X4 WIRING HARNESS | eBay

Find many great new & used options and get the best deals for T1138 1987 87 HONDA FOREMAN TRX 350 4X4 WIRING HARNESS at the best online prices at eBay! Free shipping for many products!

rover.ebay.com

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Goober

· #45 · Mar 30, 2020

shadetree said:
before you go telling him he needs another harness ?, you and him need to find out what those connectors go to ?, cuz they dont go to the c.d.i. !.

Ok i see having looked closer at the ebay harness—had the same connectors

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Goober

· #50 · Apr 7, 2020

Here’s a pic of an 86-87 A model tank setup which is very similar to the 87 D with the exception that the D has a fuel level sending unit in the tank.
that said, both tanks have suction lines with basket screens and a drain bolt.

Yes drain the tank using that bolt. Rust is a problem in these tanks but they can be easily cleaned. Especially the suction lines which also accumulate sediments—use a long pipe cleaner—if clogged, use the cutoff end of a cable.

heres a cleaning thread—darn couldn’t find it—look for TRX350 borescope

and a pic of the fuel flow config

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Goober

· #52 · Apr 8, 2020

Yeah try spraying it down really good with Deep Creep. Sometimes you can get it to start working again; Be hopeful
Replacement caps can be found but that little knob and screw is real valuable don’t break it by working it too hard.
I had a good cap with a bad knob luckily i got a bad cap And robbed the piece I needed

Goober

· #54 · Apr 10, 2020

Happens occasionally—you’ll want to buy a used cap.
cleaning a D model tank—can you remove the gauge sending unit without breaking it? my vinegar cleaning technique might ruin the bulb on the [email protected] or other D model members might be able to advise you how to remove the fuel guage sending unit without breaking it. It’s that bulb that sometimes swells and won’t clear the port.

cleaning the tank on an A model is easy because it doesn’t have that gauge sending unit. I put a pound of BBs and 2 gallons of cleaning vinegar in mine. Sealed up the openings, wrapped in bubble wrap and cardboard—put it in my cement mixer

www.hondaatvforums.net

86 TRX350 Fuel Tank Borescope

Hi bought a cheepy borescope for $20 about 2 years ago—I scratched the lens pretty bad, but it works better than nuttin The attached pix are from an ‘86 TRX350 tank—showing the interior plumbing and the screens built onto them. First is the reserve pipe with the drain bolt removed; 2nd is the...

www.hondaatvforums.net

www.hondaatvforums.net

Goober

· #55 · Apr 10, 2020

Here’s another tip.
There are two suction lines in the tank that terminate in basket screens—almost a foot long. Those lines can get clogged with sediment and rust.
My reserve line was packed so hard I couldn’t get a pipe cleaner through it. So i used an old throttle cable, cut it off and used it as a directional drill to bore through the clog. Careful! Too long and you’ll get that cable tangled up in the basket screens and hang it up—damaging the screens

Goober

· #57 · Apr 10, 2020

Compressed air won’t hurt—you’d know right away if they were clear—might not clear a clog. If you could get some long pipe cleaners from a craft store too

oh yeah these filters are pricey!

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Goober

· #61 · Apr 12, 2020

Lowall said:
Gas cap is really frustrating. It moves very freely a little but not enough for the cogs (locks??) to come out and lock it in position. Have sprayed with penetrating oil several times. I came across a thread that insisted in not trying to take it apart. Have to admit I have manipulated. Using this number 17620-HA7-671 I find none on the market. Can you use another part number?
I am planning on acid cleaning the fuel tank. Muratic acid or Hydrocholoric acid. Do these hurt the fuel level float? Do you know it you can do it in place or do you have to remove it?

Vinegar as i presented in the attached thread

www.hondaatvforums.net

86 TRX350 Fuel Tank Borescope

Hi bought a cheepy borescope for $20 about 2 years ago—I scratched the lens pretty bad, but it works better than nuttin The attached pix are from an ‘86 TRX350 tank—showing the interior plumbing and the screens built onto them. First is the reserve pipe with the drain bolt removed; 2nd is the...

www.hondaatvforums.net

www.hondaatvforums.net

Goober

· #67 · Apr 20, 2020

I would take the fuel gauge sending unit out, take off the petcock; remove the cap.
Tape all holes with aluminum tape so the vinegar doesn’t leak out and get on your tank.
Do you have a cement mixer? Or are you just gonna shake it every once in awhile? 3-8 hours outta do it
Remember to rinse with a high pH solution not plain water.
Dry with hair dryer.
Some of that pH powder is going to dry in the tank leaving a powder that will plug up your filter. So rinse the tank two or three times with a cup or two of fuel.

Were you looking for a new sending unit? Can’t remember

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Goober

· #69 · Apr 20, 2020

The petcock has three rubber seals that will be ruined by the vinegar

you have a hot tub? Use the pH adjustment powder to mix with water

Goober

· #71 · Apr 20, 2020

Pure baking soda?
Or skip the acid neutralize step

Goober

· #73 · May 6, 2020

You have the petcock off yes? The vinegar may damage the seal.
Use a cut off piece of brake or throttle cable to clear the suction lines. You can use your drill to directionally bore thru the clog but be careful—don’t drill thru the intake screens
The petcock has three positions
On main suction line open; reserve closed
Res reserve line open; main line closed
Off both lines closed

petcock rebuilds

www.hondaatvforums.net

Petcock Rebuild III 86-89 TRX350

Update of petcock rebuild procedure 86-89 TRX350; this is my seventh one—sofar I have only found one oddball with a lever that was slightly larger diameter. You can buy a set of seals on fleabay that includes the 4-hole packing, an oring lever seal, 2 tank seals and 2 screws. It will help...

www.hondaatvforums.net

www.hondaatvforums.net

Goober

· #77 · May 15, 2020

yup here are the two lines—see the basket screen aft of the drain bolt?

i cut the end off of an old cable i had i think it was a brake cable. About 12-16 inches. It has the braided metal sticking out one end.

i laid my tank on side petcock holes up and filled the line with cutting oil—so I could see when it started to drain away into the tank.

I chucked the cable in my variable speed drill i used it and some cutting oil to slowly cut through the buildup in the line. Took about 5 minutes

go slow and don’t push too hard. You don’t want to get the cable bound up in the pipe, or cut thru the pipe, or cut into the basket screens. You’llKnow you’re progressing when the oil starts getting dirty. Keep it filled with cutting oil so you know when it’s draining. That will prevent you from cutting or hanging up in the screens

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Goober

· #80 · May 16, 2020

have you laid the tank on it’s side and filled up the clogged pipe? Pour some straight cleaning vinegar in it—it’s 6% as opposed to regular 5%

Go to hardware store and see what kinds of cable they have. I’m sure they have some small plastic coated cable you can mount in a drill. Like directional boring—open up the end of that cable a bit so it can scrape away.

Goober

· #82 · May 16, 2020

Not anything worth messing with.
You could replace it with a plastic tank.
Mine has no rust after 3 years

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