Motorcycles BS Thread 2.0

Mine was a 1972 and I was 11 years old when I got it. And I also rode the wheels off of it until I was 14 and got a 1975 Yamaha DT-250. That one sustained some serious wheels off abuse.

 

Yes, Sunday November 1

 

@spencermarkd I got my carb rebuild kit for the ATC this weekend. Still waiting on tires but I’m hoping to be able to fire the motor after cleaning the points and changing the oil.
I cleaned out the tank and got all the rust and metal “corn flakes” out. It had been sitting for about 30 years with some gas in it but thankfully didn’t rust through. Filled the tank with acetone and river rocks and shook the ever loving shit out of it for a day and a half and I was rewarded with clean metal in the tank. I was able to clear the clogged reserve tube, but the main feed tube going to the carb in the tank is still clogged. Kind of a pain to clean out because it has an elbow in the tube with about a 1/4” radius so I can’t just shove a pipe cleaner in there. Any ideas to clean it out before I cut it off and weld on a new one? I want to keep it as original as possible so I want to avoid unnecessary mods or buying a replacement tank.

 

@GHOST SHIP is it possible to use an air compressor and blow it out from the outlet end backwards? With a rubber nipple on the end of an air nozzle you should be able to get a decent enough seal to blow any obstructions out. Alternative is possibly a set of welding tip cleaners. They're fairly rigid and available in different thicknesses. I've had okay success with some old Honda tanks that way.

 

Blast it out with some air? Might work if you have an blower with the little rubber end. Say fuck it and run reserve only? But really don't do that. When I first got my CB750 the PO had done a tank coat but fucked it up. Ended up with an undisclosed brick of tank coat using up all of the reserve volume. Ran out of gas, when to switch to reserve, and nada. That was a fun learning experience. I had to drill and chip away at that brick of tank coat for weeks, then use chain/nuts/bolts + vinegar and do the shake up like you did. Got all the old failed coat out and what do you know, zero leaks anyway


That's lucky you didn't have any spots rust through. I had a couple pin holes on the 90 and failed at brazing it shut so i had to do a tank coat (..properly). What a PITA.

 

Great minds think alike

 

I tried to compressor trick first and whatever is clogging it seems pretty stuck in there. For the reserve line I ended up using a short piece of 14ga wire (the stiff, solid-cooper house wire not automotive wire) and frayed about 1/8” of the end and put that in my drill. It worked like a small pipe cleaner. It’s stiff enough where I can push it through the tube and flexible enough to follow the elbow. I can look through the gas cap and see the wire come out the reserve feed line extension, but for some reason the main line won’t budge.

 

I thought about just running through the reserve line but it would only give me about half the capacity of the tank. Haha. That’s like less than a pint of gas.

 

So the main and reserve metal lines are actually a part of the tank on these? The couple of vintage Honda units I've messed with have all been street bikes and the fuel line inside the tank is actually part of the fuel petcock so that's easily removed and dealt with on the workbench. I know you'd like to stay pretty original but if needed what about drilling that area and tapping it for a later fuel valve like I've described?

 

My 90 has two output barbs on the tank, not a single tank integrated petcock. Petcock is on the carb itself. Inside the tank, the main line goes up about two inches above the bottom of the tank and the reserve one is flush wtih the bottom. Reserve can access the full tank if you just ran on the reserve all the time.

 

Yeah that's not what I'm used to seeing. Would be interesting to know exactly where the clog is and if you could cut the metal tube just below that. You wouldn't hit reserve quite as quick and your reserve would be smaller though.

 

I thought the reserve line was the extended tube in the tank. The way it made sense to me was the extended tube would fill up when the tank was full and the small amount of fuel that stayed in there (plus the 2” hose going to the petcock) was how much fuel you’d have as reserve once the main tank was empty. These things barely sip fuel so that should be enough to get you moving I suppose. I can’t see the opening of the other line inside the tank but assumed it was flush with the bottom of the tank. Either way, the non-extended tube is the one that’s clogged.

I’ll have to keep tinkering with it before I resort to cutting it off.

I also ordered the Haynes manual for the ATC so hopefully that’ll provide a little insight once it shows up this week.

 

@GHOST SHIP quad lock vibration dampener is out

https://www.instagram.com/p/CHF9mhynZNw/?igshid=1xjhpbh717itc

 

Extended tube is your main line, when that runs dry you still have the volume below the mouth of it as your reserve. Like 20% of the tank of whatever amount it is down to the bottom flush one.

Can you tell where in the tube it's clogged? Any chance of getting at it with a long drill bit or something from the filler neck?

 

The tall tubes on a petcock are your mains. The reserve is the short tube.

 

New rubber front and rear, 4 mil tubes, and added rim locks so I can more confidently air down.

 

That makes more sense. I can probably run it like it is and just have no reserve but that’ll shorten the amount of fun. Haha. The clog is just past the bend. I tried a drill bit at first and got right to the bend in the tube. I’ve tried dental picks, a bore brush for .223 and the wire trick. I might try letting some solvent sit at the bottom of the tank and try to softener whatever is in there so I can keep chipping away at it. If I was able to get at it from inside the tank it might be a lot easier but I can’t see it much less reach it with all the tools at my disposal.

 

I'm just so intrigued what it is at this point. Let us know when you get it figured out.

 

Okay, this information sparks another idea. Get some tubing that will be a snug fit on the exposed portion of the tube that you can get to. I would put the tube over that and use a small hose clamp to secure it. Invert the tank and using a squeeze bottle fill the tube with a solvent of some type like acetone or lacquer thinner and let it sit for several hours. With gravity working to keep the solvent against the clog that should allow the solvent time to work and break down whatever is in there. I'd recommend blocking off any other openings like the filler neck so you don't mess up the paint assuming the paint is in good shape and you want to keep it.

 

That sounds like a plan. I’m hoping it’s just some kinda coagulated fuel booger and I comes out clean. The paint is in decent shape and I’ll probably give it a good polish. My last round of acetone faded some of the ink on the decals so I’ll be getting new ones once it’s running.