Welcome !

1) Here's my top 3 guesses....
• Stale, out of date gasoline
• Stale, out of date gasoline
• Stale, out of date gasoline

2) Now the stale gasoline has also fouled the plugs (replace) and most probably clogged the carbs (rebuild).

3) Then read this as follow up...
https://www.airheads.org/forum/technical-discussions/992-new-owner-primer-tips-to-get-your-airhead-back-on-the-road

Hope this helps.

100% agree with Wobbly. I had a similar circumstance with an 84 R80. I drained tank, flush with clean fuel, change plugs and bike started and ran ‘fair’. I also discovered a cracked coil which allowed moisture to prevent starting. After replacing coil the bike was excellent. I got lucky and carbs did not require rebuild. The coil crack was not readily visible.

The thing is, 99% of the problem is inside the carbs... BUT if you can simply get the bike to run "pretty good", then you can start using a high-octane, name brand fuel (which most probably has a cleaner built into the fuel). If you wish, you can supplement that cleaning action with a product called StarTron (sold anywhere they sell lawn mowers and powered garden tools). THEN, as you ride the hard to get to areas of the carb and fuel system will be scrubbed spotlessly clean.

The bike will start to run better and better every time it's ridden. The transformation will be very impressive !

Read up on Top Tier Fuels here: https://www.toptiergas.com/

Thanks very much! I am going to hit all of the above this Saturday and will report back with the result! I know that the carbs were rebuilt as part of the big service the bike had recently, if i can get around rebuilding the carbs using the StarTron that would be great!

Kyle

Thanks very much! I am going to hit all of the above this Saturday and will report back with the result! I know that the carbs were rebuilt as part of the big service the bike had recently, if i can get around rebuilding the carbs using the StarTron that would be great!

Kyle -
Very positive thinking, but unfortunately that not how it goes. North American fuel goes bad, starting about 6 weeks after purchase, unless you take steps to "stabilize" the fuel. That is to say, the gasoline and alcohol start to separate, and then things REALLY get out of control. It all blows up in your face in the fuel tank, in the fuel lines and inside the carbs. StarTron will help stabilize ethanol fuels.

It does NOT matter that you just had this work done. You've now allowed the bike to sit with fuel in all 3 places, so the clogging and corrosion start up fresh all over again. Go directly to jail. Do not pass GO. Do not collect $200.

Highly advised, sir, that if you park the bike for longer than 4 weeks, simply drop the float bowls off both carbs. If you need to leave the country again (and thank you for your service) simply empty ALL the fuel from the tank, lines and carbs. In that way you'll come back to a runner just like you left.

Carburetors work by vacuum, and there is simply not enough to pressure with vacuum to clear a completely clogged jet, orifice, or passage way. However, if the cleaners can pass through an area that's only restricted, then they will wash it out back to a "showroom" clean state within a couple of weeks. StarTron will enhance the cleaning properties found in the better grades of ethanol fuels.

Hope this helps.

So based on what I’m hearing, my plan of work should look like this:
1) drain fuel from the tank and lines
2) replace plugs
3) add fresh fuel and see if I can get it to run
4a) if it starts and runs, add StarTron
4b) if it won’t start rebuild the carbs

Close to the mark?

I never knew about the fuel having a life of only 6 weeks. I have to leave again in late February.

Thanks again,

Kyle

So based on what I’m hearing, my plan of work should look like this:
1) drain fuel from the tank and lines
2) replace plugs
3) add fresh fuel and see if I can get it to run
4a) if it starts and runs, add StarTron
4b) if it won’t start rebuild the carbs

Close to the mark?

I never knew about the fuel having a life of only 6 weeks. I have to leave again in late February.

Thanks again,

Kyle

So based on what I’m hearing, my plan of work should look like this:
1) drain fuel from the tank and lines
2) replace plugs
3) add fresh fuel and see if I can get it to run
4a) if it starts and runs, add StarTron
4b) if it won’t start rebuild the carbs

Close to the mark?

I never knew about the fuel having a life of only 6 weeks. I have to leave again in late February.

Thanks again,

Kyle

A better version...

1) drain fuel from the tank and lines AND CARBS. Every bit of old fuel has to come out.

5) Drain all the fuel again before leaving in February.

UPDATE:

Thanks for the help with this. I ended up being out of town over the weekend but got some time to work on the R65 today. I drained the tank from the petcock and noticed that the gas had taken on a coppery color. After draining from the tank, I dropped both float bowls to discover golden brown gas in both and some nasty gaskets. the one for the left carb was deformed and broke as soon as I tried to lift it from the bowl. Can't believe they deteriorated so fast.

I've decided to rebuild the carbs as i assume that they're most likely in pretty bad shape based on the gaskets.

Any recommendation on spark plugs for this model? it looks like the original Bosch plugs are NLA.

Thanks again!

Kyle

I've decided to rebuild the carbs as i assume that they're most likely in pretty bad shape based on the gaskets.

Kyle -
Do Not draw conclusions on your whole carb from the float bowl gasket. Bing gaskets are usually good for one single use. Typically wise riders buy them 10 at a time. There are lots of 3rd party shops selling these in volume for discounted prices. Mottorad Elecktrik might be a place to start. There's another that sort of specializes in carb parts, starts with an "E" but its name eludes me right now.

Any recommendation on spark plugs for this model? it looks like the original Bosch plugs are NLA.

NGK BP7ES available from any auto parts store. Test for presence of spark by plugging both plugs into caps and laying them on the head. Then grease the threads before installing the plugs into the cyl head.

well I got the spark plugs done today and replaced the old fuel with new + a little StarTron. Unfortunately, I wasn’t able to get the bike to run.

I got some very thrilling chuffs where it seemed like the bike would catch and run but each time as soon as I let go the starter she died. I found that I had the most success with no choke and a hair of throttle. I eventually ran the battery down and had to hook up to the car. Even so, no joy and it soon got to where the battery wouldn’t really hold a charge even from the car.

Any ideas what should be next? Besides maybe a new battery?

If you tested for ignition spark on both sides as suggested, then the orifice in the bottom of the float bowls is next, then the idle jets in the bottom of the carbs. Smaller jets clog first.

All,

IT"S ALIVE! haha Before doing anything else, I went back and tried jumping it by connecting the negative ground directly to the battery. This resulted in substantially more power going to the bike and allowed me to crank the living crap out of it for a while. it finally caught and after nursing it with very delicate inputs on the choke and throttle, She settled into a rough idle. I can't thank you guys enough for guiding me through this! Wobbly especially, your beginners guide has been wonderful to read!

Next time I've got to leave, i'll drain the tank and drop those float bowls!

Kyle