One year upgrades! 1984 ATC500X

[rustyhondas]

Good for you !

Allot of challenges along the way , hell of a job making that crazy intake work

Not sure about those skid plates on a race bike , you can totally get away with not having them

[plevib]

Thanks! Yeah the skid plates ended up really heavy duty cuz that was the thinnest diamond plate the place had haha. ... I'm just getting into racing so I suspect this will mostly be a trail rig. But I didn't think about pulling them off for races, that's a good idea!

[plevib]

Assembly! Finally!

[plevib]

Getting there!

[plevib]

Almost there

[plevib]

Holy crap it's been a long road getting it here! But it's a monster! Crazy torque! It's really rich on the top end so I've got more carb work to do, but it pulls like crazy on the bottom end. I'm gonna drop the front sprocket to a 12t, cuz 14 is really tall. I'm gonna fab up led headlights for it with a 350x headlight shell. And I want to get a mikuni for it because the two stroke idle adjustment doesn't work well on this engine. I also want to bend the forks back, get new fork boots, it needs new handlebars, and I'll probably get new controls for it too. And a tether kill switch. But it drives!

[DohcBikes]

While jetting don't rule out the intake as a possible cause for issues.

It looks great, very well done.

I passed on purchasing a 225dx with an xt500 engine a few weeks ago. It was not built well like yours is.

[plevib]

https://youtu.be/4-puKryWNyc

[Jmoozy27]

An keihin fcr carb off of any modern four stroke dirt bike should get you in the ballpark. Looks really nice and original. Good job.

[DohcBikes]

^ excellent suggestion.

They are a bit pricey but I know for a fact that a DRZ400 carb will run that engine very well.

[86125m]

I fi did not know any better I would say it looked factory. You have done a wonderful job does not look home made in any way.

[ps2fixer]

Are you using the OEM left side switches from the 250r? There are a few options out there for replacement switches. If you shot me some photos of the plugs and wire colors I could probably wire one up for you to be plug and play (colors might not match). Here is what the switch looks like. It has a "spare" starter button, but a horn or something witty could be wired up to it. Would be pretty simple to add in an option for the tether to be parallel with the kill switch too.

Thing to remember if you're looking to source a switch, most of the newer model quads (like 95+) have the reverse electronics for the kill switch. So if the 250r kill switch is correct for your engine, then a newer switch would work backwards (off for on, and on for off). The one photoed below is one of the few left in production with the old style of kill and would be correct for pretty much any Honda atc.

Photo is the 350x switch assembly I replaced =). New one works so much better than the old one.

[plevib]

Thanks for the advice and compliments! I'm glad you guys think I met my goal of a stock, honda looking build! I tuned it a little more last night. Before I got rained out I got it pretty much dialed in. It just needed leaned way out. I got a quick zip in before the rain got too bad and it revved all the way up without hesitation. But I definitely need a 12t front sprocket. .... I'll order one this week.

As far as the carb, there's no way that drz 400 carb will fit haha. Thanks for the suggestion, but I figured I'd just go with a mikuni vm36. Fairly cheap and compact. Then it'll actually idle haha.

And as far as the electrics go, the harness is built from scratch. And ps2fixer, sorry when I said controls I meant clutch and front brake.

(I'm an electrician, so a clean harness with new wires and electronics made me happy) right now I've got the lights hardwired because I usually never turned them off anyways and I'll pull the headlight for races. And the only control is going to be a tether kill switch. I like simplicity.

[plevib]

https://www.youtube.com/watch?v=zFINukEcCRE

Here is a walk around video

[briano]

Very nice, good job on your build. I was almost one of the naysayers when you started this project, but I wasn't. Again, good job, that looks like it should have came that way. How hard would electric start be on that? I'm not real familiar with that engine.