Just to add to Pat and Red have said, you mentioned backfiring through the carbs, and with good compression etc off suggest that the carbs you're using need cleaning and proper setting up (float heights, balancing and ask passageways in the carbs clear) before you take the bike out for its first test rides. I'm a big fan of ultrasonic baths for cleaning carbs.

Sure is!

Sorry about the crappy pic lol I didnt know I was going to end up pulling the tank when I took it and decided to not take another after doing so.

Quote from: JohnnyTheCraneGuy on December 29, 2024, 05:34:49 PMthe good is that the damn petcock is safety wired! Made me wonder if the PO was maybe even a member on here at some point or at least knew someone. Still, cant say I didn't smile when I saw that.

Johnny,

Can't quite see the safety wire.  Is this what you have?

https://fjowners.com/index.php?msg=27126

Thanks Pat. It's about 30 degrees here in NJ the days I've been idling the engine so I thought it was ok but maybe you're right and I'll put a big fan on it next time to be safe.

Your compression numbers are ok so I think it's your valve seals.

Funny thing about valve seals, they do dry out and harden from long term storage, but they also soften up once some hours are put on the engine.

They also get cooked from overheating the engine.

That big displacement air cooled engine absolutely needs air flow to prevent the burning of exhaust valves, valve seats and valve seals. 10 minutes idling is too long without a box fan to cool those cylinders.

You can (and will) ruin your engine by letting it idle too long without airflow.

My recommendation: Run the bike, see it the seals get better. 

Just wanted to give yall an update on things.

I ended up pulling the starter, and generator to get full access to the pickup coil wires. I ended up cutting back the burnt loom and to my surprise the wires inside were shielded from the damage! All of them were to very flexible didnt show cracking. I ended up deciding to just keep the stock wires for now, I gave them a fresh wrap of tape and used this heat shielding I purchased from amazon.

https://www.amazon.com/dp/B0BLLGLSN8

I gave the generator the same treatment, and when I went to reinstall the starter I had noticed some pretty good pitting on the ring. I picked up a nitrile kit from harbor freight and installed a 20x3mm. I'm honestly not happy with it though. I couldn't find anything on the size of it either in the service manual or on Partzilla, etc. What size worked for yall?

Oldrider,

Hi
if it was my bike i vould start checking it like this:
1 I suspect it's coming from the valve seals but I'm not expert.

2 oil level is about 3/4 up to the top line so I don't think it's overfilled and I am running the engine with the bike on the center stand.

3 I will do this next time I run it.

4 I don't think it's overfilled, I was running no air filter and now pod air filters and didn't see any oil.

5 I'll start it another time and then pull the plugs after that and check them thanks.

6 I'll check amazon for this camera.

6.5 Valve cove gasket definitely needs to be replaced. I don't think the small amount of oil leaking past the valve cover gasket could cause this but maybe?

7 Before starting the bike for the first time I filled all cylinders with Marvel oil for about a week or two, then pulled the plugs and turned it over.

8 I lean towards the valvestemseals being old/dry because they are likely original to the bike and I know the bike sat for at least 15 years in a garage. Is there a thread on here about how to change those out? I searched around but couldn't find a tutorial. I wouldn't just do that now I agree I think I need to ride it a little first to see what happens with the smoke over time. I'm just nervous about putting more $ into it if it needs a major overhaul.

Pat, 10 minutes is about how long I let it run for, enough to let it warm up. I'm trying to get a sense for how well the engine runs before taking next steps. Wish I could ride it but before I can ride it I'd have to do clutch, brakes, tank, chain and tires (tires are 20 years old). I could do clutch, brakes and chain and maybe go around the block slowly a few times with the water bottle gas tank I guess.

Sorry if I wasn't clear the video was not exciting it was the only thing that came to mind about how to show everyone the smoke.

Hi
if it was my bike i vould start checking it like this:
1 smell the exhaust .on the video t look maybe a little blue so it is most likely oil .But then where does it coming from?

2 it might just be overfilled so check the oil level it should not be too high i like to keep it in the middle of the min and max mark in the sightglass

3 with engine running open the oilfiller cap does it blow much? if it does the piston rings might stick allowing air blowby down into the case.Or in i worce situation the rings and bores are so worn that it blows by .

4 check airfilter and box are there oil in there if there is you might be lucky that it is just overfilled  ?the oil can find its way all the way from airbox into the combustion chambers.

5 .Next i vould take out the plugs an look for oil on them (or actually i vould do that earlier)  only one is oiled it may just be a problem with that cylinder.
maybe a valvestemseal vorn out.
if all 4 is oiled it pointing toward sticking rings or worn bores. but check more first.

6 i would have used my tiny cheap usb to phone  snakecamera  down in the cylinderbores with the cylinder at btdc.
That is a great way to check what you got. It will show the honingmarks or  if you can not see any it indicates that
the bore is vorn. you can also se the top of pistons if they are dry or oily. But the best with the usb snakecamera is
that you can turn it upside when down in the bore using a steel wire .(i will post a pick of that tomorrow)  then you can look at the valves from underside if you see oil hanging from a valve you can be sure it is has a bad valveseal.
you can also se if the bore has a deep grove almost at top of the bore if it does it is vorn.

6.5 in the vid i looks like is smokes a little from the front of engine.Check if the it is coming from valvecover gasket
or more likely from the rubber grommets on the coverbolts. then check if it is coming fom the exhaust flanges
if from flanges it can be a leaking valstem seal. you can also take off the headers and have a look if it is oil there.
check if there are any leaks from the headgasket!!

7 .but first thing i would do with your bike is since it has been sitting so long there is a great chance that the rings are sticking.
use some teaspoons or more with marvel mystery oil or wd_40  in the bores and let it sit over night. next day look in the bores that the oil has drained down or just turn the engine over with the plugs out  to be sure there is not a load of oil down there making a hydrolock.
Then i vould take it for a ride and slammed the throttle accelerating hard several times and also using engine brake hard often. push the engine with high revs  this can free up the rings again.

8 in the video it looks a little like it smoke  more when letting off throttle that can indicate vorn valvestemseals.
but first try to ride the bike a little hard.or harder but be careful! good night sir

Unfortunately not in the market for one at the moment but have been on a short list for me for a few years now. Great looking bikes in my opinion. Got to see my first one out in the wild in Pigeon Forge TN this past October, they guy was pulling away with a few other bikes so I didn't get to stop and look at it up close. His was a white one. Nice bike. You getting a different bike? Just curious as to what if you were.