1986 Fourtrax 350 - Fix and Ride

Done
Valves adjusted
Carb cleaned
Rear brake cable installed
New spark plug
Oil changed
New gas tank mounted
Replace choke rubber / plastic
Install gas tank guard
Install rear hoop / rack
Differential fluid replaced
Reinforce front plastic
Reinstall front plastic
Reinstall front racks

To Do
Refinish HONDA box
Brake cylinder fluid replaced
Repair foot brake lever

Rear rack and plastics put back together, gas tank guard mounted, choke plunger rubber replaced, plus I got to ride it for a little bit!

I need a rubber bushing for the rear rack primary attachment arm-- only one side had it already on there. I went ahead and mounted it anyways! Found out I'm issing a single piece of plastic on this thing, the one that goes over the battery (not the hinged cover part).

The gas tank guard was a pain. The plastic tank isn't conformed like the metal one was, so after much banging on an anvil and bending on the vice, I was able to make it fit and bolt it on.

For those wondering, the choke plunger rubber from a 2000 TRX450 does indeed fit this bike. None of the other parts from the kit fit! That was an expensive piece of rubber, but it seals. Also, I guess I had enough plastic thread on the cap to seal it up. I'll need to get a replacement before I go to take it off again, I don't think those threads can take much more.

As mentioned, I did ride it around a little. It was idling OK, albeit a little low with the idle set screw at ~75%. When I got it, that thing was tightened just about all the way. What's up with that? It's also still running rich, I pulled the plug after ~5 minutes riding.

Oh yeah, I changed the oil filter cause I forgot to do that yesterday when I changed the oil. Turns out, the PO had put the filter in backwards!! The rubber ring was partially pushed into the hole by the spring. Oh well.

Next steps, differential fluid swap, pull off the rear brake pedal and get it welded back together, put front plastics back on.

The OEM choke valve is ~$30 and comes with everything needed to hang it on the throttle cable.
That bushing is also available too I can't remember PN I have both in one bag 52486-074-000 for the metal collar and 81303-958-680 for the rubber

Oh yeah you can find the lil battery cover on eebae every once in awhile for $20-$50 depending on condition

Maybe it is the choke hardware. It looked fine and travels smoothly, but I didn't really measure anything. I'll go ahead and order a kit cause like I said, those plastic threads won't take a lot more punishment! I haven't messed with the pilot screw yet, it's 1-1/2 turns out at the moment per FSM.

@Goober, thanks for those PNs. Need to order that and a couple little bolts/screws that were missing. Wish I could find a dealer for small parts like this that does free shipping! Edit-- Hey, that part seems to be the Front Carrier rack bushing... do you happen to know if the rear is the same size?

I've got a game of 'identify that part'! Can anyone help with the attached pics? Heck, they might not even be from this bike-- they were just in the toolbox along with some other hardware that I've found where it goes.

The 1st pic looks like a left-front shock absorber lower mounting bolt? Screws into the top of the front diff.... it snapped off.

The 2nd pic looks like the bolt that holds the muffler forward mounting bracket to the frame? It goes just back of where the muffler slides over the header pipe... refer to pic #5 for the rest of this guess...

The 3rd pic looks like a lower front shock absorber rubber bushing. The story behind that bushing coming out of the front shock is probably explained in the same story that the busted shock bolt in the 1st pic would tell... if it could talk.

The 4th pic looks like it could be a seat bumper like you said... it could also belong on the front diff skid pan. There are three of those I think (or 4?)... pressed into holes on the inside of that front skid pan to cushion the aluminum diff housing from any sharp blows to the bottom. The story behind this pic may be heard from the busted shock bolt and shock bushing as well. The rear diff skid pan has rubber bumpers too, but I think those are cone-shaped bumpers about the same length.

The 5th pic looks like the backer nut and bracket for the muffler mounting bolt guessed in the 2nd pic. That bracket extends toward the right side where vent hoses clip to it before making the 90 degree bend at the left frame rail and routing up to the steering head where those hoses are retained.

Any prizes...

Edit,
I didn't see any letters & numbers on that NGK spark plug box, but I assume that is a new DR8ES or DR8ES-L spark plug. Or was...

According to Partzilla the 87 350 D rack f n r used the same bolt bush and sleeve

Thanks @Goober ! I couldn't ever find the fiche for those racks since they didn't come on the '86, now I know to look for the 87.

retro said:

The 1st pic looks like a left-front shock absorber lower mounting bolt? Screws into the top of the front diff.... it snapped off.

Click to expand...

Good guess, but that bolt is there and secured.

retro said:

The 2nd pic looks like the bolt that holds the muffler forward mounting bracket to the frame? It goes just back of where the muffler slides over the header pipe... refer to pic #5 for the rest of this guess...

Click to expand...

Maybe? I can't quite see where that bolt might go with the plastics on. Although, I probably need to take the muffler off as there's a hole in the bottom

retro said:

The 3rd pic looks like a lower front shock absorber rubber bushing. The story behind that bushing coming out of the front shock is probably explained in the same story that the busted shock bolt in the 1st pic would tell... if it could talk.

The 4th pic looks like it could be a seat bumper like you said... it could also belong on the front diff skid pan. There are three of those I think (or 4?)... pressed into holes on the inside of that front skid pan to cushion the aluminum diff housing from any sharp blows to the bottom. The story behind this pic may be heard from the busted shock bolt and shock bushing as well. The rear diff skid pan has rubber bumpers too, but I think those are cone-shaped bumpers about the same length.

Click to expand...

Sorry, I tricked you on this one-- that is the same part from different angles. I was looking at the fiche wrong, I don't think it's the seat bumper. Those four rubbers are in the frame, unless there's a second rubber piece that goes over the plastic rods on the bottom of the seat pan. I haven't pulled the diff skid pans yet, so it could very well be from there.

retro said:

The 5th pic looks like the backer nut and bracket for the muffler mounting bolt guessed in the 2nd pic. That bracket extends toward the right side where vent hoses clip to it before making the 90 degree bend at the left frame rail and routing up to the steering head where those hoses are retained.

Click to expand...

Yep, I'll have to do some more digging on this one but you could be right. PO might have though taking the muffler off would make getting the gas tank out easier..! He didnt' have the handy tip from Shadetree about disconnecting the rear shocks and lifting the quad ;-)

retro said:

Any prizes...

Edit,
I didn't see any letters & numbers on that NGK spark plug box, but I assume that is a new DR8ES or DR8ES-L spark plug. Or was...

Click to expand...

You nailed that pesky part!! Lol. Thanks for taking the time to look through these and make some guesses. For your trouble, you win... a TRX350 gas tank with a golf-ball-sized rust hole in it!

Too much slack in the throttle cable or
You didn't adjust the throttle valve linkage properly