farmerbrown

21 minutes ago, jeepwm69 said:

One problem fixed, another appears

 

Such is life!

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.

47 minutes ago, Misterclean said:

You need to confirm that it loses spark before doing anything else. Pick out a screw driver or something similar that fits into the spark plug cap and can also be positioned so the steel shank can spark against a cooling fin or anything else that is clean and grounded, Then when it dies again, quickly check the spark by the proven method you came up with. Two very common problems are a dirty kill switch and a coil wire. The coil wire/spark plug lead can be trimmed back about a half inch or more which exposes a non corroded portion. The black plastic cap just screws out of the wire and screws back into the wire. The resistor you mentioned can cause problems as well.

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.

3 hours ago, Fishfiles said:

That 90 was the first one , good read :

 

https://atvconnection.com/articles/honda-atv-history-in-the-beginning-3/

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.

5 hours ago, Fishfiles said:

Your right ,  1976 ATC90 >>>   I was not going back that far , 1976 is as far back  as Partzilla goes with ATCs and 90 was the only one that year   , 1978 was the first year for  the 70 

 

Here are a copy of prints , quite a few spots it could be froze up at 

 

 

 

  

47 minutes ago, Fishfiles said:

What year is it ?  You say it is it a 90 , could it be a 70 ?  I don't see a print for  a 90 , but do see a 70 ..... 

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

heres the pic

I having trouble getting this front axle apart. If I understand the manual properly those spacers on each side of the hub should just slide off. Well they don't. I've tried heat wd40 a pipe wrench to try to twist it and I'm trying to figure out a way to use the shop press but I can't get it to budge. I can't get an pictures to upload now so I'll try again in a bit

Just ordered a bunch of parts. Boy isn't that fun.

I hink im done taking stuff apart! I have to paint alot of stuff yet. I m working on the fuel tank now.

Ok thanks for the advice. I got the wiring harness tested and repaired and washed and prepped for painting the frame today.

I got the engine off and am working on rewiring it. I put some vinegar in the gas tank and it uncovered some holes I couldn't see before (see pic). Can this be sealed with gas tank liner or will I have to take extra measures. They are about the size of a pin head.

I'm done tearing apart for tonight. I got that screw out with a small battery impact driver. Believe it or not the alternator works so we may not have to replace that. Im just about shot. 

I'm getting it torn apart. It looks like ill need new rings alternator, tires, rear axle, and gaskets and more that I can't think of right now. The jug looks good and the piston looks good. The transmission seems to work fine. The picture showing the Philips head bolt that is stripped out I can't get my Dremel down there to cut a slot to use a flathead screw driver and I need some ideas on how to get that out

My new project. I hope some on here have knowledge of these ATC90s because I may need advice on rebuilding it. My dad rode this one as a kid and he would like it to run and I need something to work on in my spare time. So I've got myself a project. The gearshift moves freely and the neutral indicator works but I can't get it to turn over with just the pull rope. I'm gonna get it in the shop tomorrow and start tearing it apart