farmerbrown

Yeah but at least this problem is just a matter of spending money and fitting it on no diagnostics. Did I ever say I didn't like diagnostics.

Well IT RUNS I got the plug today and it appears to have fixed it. But when I was driving around I broke the chain. I thought it was fine earlier but I guess not. Pics will come maybe tonight.

Sorry guys. The spark plug won't get here till Monday or later and I haven't been home much today.

It's a 76' Here's the part diagram off of partzilla. The points a on one end of the camshaft.

This evening I tested the spark with a screwdriver and it was fairly strong. I tested spark with and without the boot on the wire and it didn't seem to make a difference. So now I think it's probably the plug. We will see when it gets here.

You don't mention the condenser so apparently that can't be the problem. I'm just trying to figure out what parts to order.

The kill switch can just be unplugged because all it does is bypass the plug and I tried when it was running once. Yes I did trim the wire back to some non corroded wire. I have been pulling the plug and holding it against the head to check spark but it seems there is rarely visible spark. I will try using a screwdriver or something.

I found an thread on Honda Atv forums where a guy suggested the plug cap for a person with a similar problem. They apparently have a "anti noise" resister that can cause these problems. He also suggested cutting a bit off of the coil wire which I tried to no avail. I should try a new plug.

Well folks probably time for an update. I did get it back together not too long after my last post and didn't start for no apparent reason had spark, fuel, and compression. Eventually my older brother came over did nothing different and it fired right up. Anyways it ran for that day and the next and then quit. I work on it for a while (can't remember what I did) didn't ever start. Just lately I got inspired (sorta) and I adjusted the valves, cleaned and adjusted the carb, and messed with the timing some didn't start. Then just today while cleaning the shop I yanked the starter cord with no faith and it fired right up . It ran most of the afternoon and now it won't start like it has no spark. So what might it be? Condenser? Coil? Plug? Plug wire?

I didn't work on it any this weekend because of end of school activities but I'm back at it today. Most of my parts have arrived but I'm still waiting on piston rings. I need 2 4 inch pieces of fuel hose and I can't find any around the farm but I did find an old 450S carb and the vent hoses on it are the correct size. I suppose that wouldn't be safe to use that but I'm not sure. Thanks

Yeah I was using vinegar. by fuel tank is getting mostly shiny on the inside but when I tipped it upside down my tape job on the the fuel fill hole didn't hold so I lost my vinegar and we don't have enough to fill it back up. I don't think sealer will hardly hold as it is.😒

The Initial US90 was offered at $595 in 1970, and featured an 89cc engine producing 7 hp. The US90 designation was used until 1973, when Honda successfully trademarked the moniker ‘All Terrain Cycle’.[2] The designation was then changed to ATC90. This is from Wikipedia I think maybe they were for sale in japan earleir .

I've heard about Tacheuchi but I didn't know the whole story about him. I'm getting same of the wheels painted on the inside after wire wheeling them. They are pretty pitted but not right on the bead so I think they'll hold air. This is what she looks like right now.

Yep that's a good read. In school I did a research report on the history of Honda atvs and I thought I had read every thing there was a bout atcs but I must have missed that one. I am working on the front axle now. There appears to be a spacer on each ide of the hub to keep the hub centered and those spacers should slide right off but they rusted onto the axle.

The vin says 1976 ATC90 and the plastics say ATC90 but out of curiosity where did you see 70