Topic: clogged fuel tank crossovers CB350, creative solutions asked for

[MoMo]

Present job in the shop is this CB350 twin.  The owner cleaned and lined the tank with Caswell(not sure but it is silver) and failed to block off the lower crossover feeds.  Clogged solid with liner which prevents more than half of the fuel able to be used.  Any ideas other than having him remove the liner?  I've attempted to run a wire up but it met with staunch resistance.  I have thought of cutting the bend off and drilling out the liner but I'm not sure if I'll be able to connect fuel line  to the stub that would be left.  Here are a couple photos....Larry

[02z06dave]

I guess he skipped the step where you blow a steady stream of air in to prevent it from blocking those holes.

If you get something long and sharp, you might be able to get a good angle on it from the top, but I doubt it. I think your idea of cutting them off or removing the liner are about the only options.  Caswell is tough to remove too, so that would suck

[Cougars750F0]

You might  try cutting  a section of braided cable, piano or guitar string and running through a drill to clear the liner away.

[tbpmusic]

Try a guitar string, one of the wound types, like a lower E string. Spinning it might encourage the string's winding to auger in........

[MoMo]

Try a guitar string, one of the wound types, like a lower E string. Spinning it might encourage the string's winding to auger in........

I tried using a piece of inner speedo cable on a drill...............not much luck..   Thanks for the suggestions so far....Larry

[calj737]

I had this problem on a tank for someone. I heated a piece of stainless rod and stuck it in a drill. Shoved it in and basically cauterized a hole through the liner. Once I hit the elbow, I switched to heating the rod with propane while shoved in. Took some patience and determination, but ultimately got through.

[strynboen]

cut the bend end off the studs...så only the straight ends stick up...then drill straight Down...and use some safty clips to hold the tube ekstra safty on the short studs

[ekpent]

 Drill the junk out of the straight part until you get into the bend. Lay the tank at an angle where the tube is upright and with a syringe or other tool carefully fill the newly hollowed out tube with a good quality thin and not a paste paint stripper, which may possibly be available at Home Depot  and let it soak,refill as necessary and after awhile go at it with a piece of braided cable on a drill after it has softened nicely.
  Not much stands up to methylene chloride which I think is the nasty in good stripper. I have removed Kreeme very quickly with it in the past. 

[MoMo]

Thanks for the suggestions.  I'll give both a shot and get back...  I'll post some photos of the bike too, typical "cafed" 350-pipe wrap, clubmans, loud and upswept exhaust.  No hump though....Larry

[Bailgang]

What a coincidence, my current project is a cb350 twin and I just re-sealed it with POR 15 tank sealer the other day and its cross over tubes got plugged too. Fortunately I was aware of that possibility and did my best to keep them clear as I drained the excess POR 15 but the suckers still got plugged when I checked it yesterday. Luckily for me it was only plugged at the very ends and I only had to drill about a 1/4" deep and both were clear. If yours are plugged solid as in all the way through the elbow then I would suggest doing what Cal said except maybe use acetone to soften it up, my tank had been previously lined with Kreem that was falling to pieces and acetone did a pretty effective job of stripping it.

[calj737]

If yours are plugged solid as in all the way through the elbow then I would suggest doing what Cal said except maybe use acetone to soften it up...

Be careful with Acetone and heat/fire there Scott.  If you do soften up the liner, some residual Acetone will still be saturated into the liner, and the use of propane would not be good near it.

[Bailgang]

If yours are plugged solid as in all the way through the elbow then I would suggest doing what Cal said except maybe use acetone to soften it up...

Be careful with Acetone and heat/fire there Scott.  If you do soften up the liner, some residual Acetone will still be saturated into the liner, and the use of propane would not be good near it.

My problem was that at first I thought the tank was in decent shape but it wasn't until I got the bike up and running again last weekend and gas being in the tank for the first time in who knows how long that the Kreem started falling to pieces ...... of course this was AFTER I had repainted the tank so rinsing the tank with acetone had its risks not only because acetone is so volatile but it's not nice to fresh paint jobs either. Fortunately I was able to strip the Kreem and then go through the process of prepping  and re-sealing with POR 15 all without harming the paint or blowing myself up. Right now though I have to wait at least another couple of days for the POR 15 to fully cure before putting any gas in it.

[MoMo]

thanks for all the warnings.  If I am able to pour some acetone into the pipe would that soften the crap enough to possibly force the old speedo cable through?

[calj737]

Personally, I doubt it. Its been my experience that Caswell just laughs at Acetone. The only chemical I've found that intimidates it is MEK. But, I would rather have the hardened liner inside the crossover to help "guide" the rod or drill bit then to have a gooey mess in there.

You could use a drill bit and create a "pilot" hole for some other type of cable/wire/rod to use to help expunge the rest of it. Or see if that pilot hole is sufficient to use when you pour some chemical in it to help soften the remaining "sleeve" of liner?

[ekpent]

  Did they slop any of that tank sealer on the on the back side or bottom of the gas cap Larry that you could test the acetone on ? http://www.jockeyjournal.com/forum/archive/index.php/t-160977.html

[MoMo]

  Did they slop any of that tank sealer on the on the back side or bottom of the gas cap Larry that you could test the acetone on ? http://www.jockeyjournal.com/forum/archive/index.php/t-160977.html

nope, cap is clean.  Not sure what brand of liner other than it is silver(not David) and was very well done save for failing to plug the crossovers..  I was able to clean out the liner up to the 90 deg elbow.  continued thanks....Larry

[MoMo]

I had this problem on a tank for someone. I heated a piece of stainless rod and stuck it in a drill. Shoved it in and basically cauterized a hole through the liner. Once I hit the elbow, I switched to heating the rod with propane while shoved in. Took some patience and determination, but ultimately got through.

Cal are you saying that you heated the elbow or the rod?


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[calj737]

The rod. Used the heat transferring from the rod to soften the liner enough to plow the rod deeper.

[MoMo]

The rod. Used the heat transferring from the rod to soften the liner enough to plow the rod deeper.

thx, enjoy the holiday...Larry

[MoMo]

Mission accomplished    I used MEK substitute(of which I have a couple gallons) and a small  syringe along with a piece of speedo cable attached to my cordless to Break on through to the other side(.The Doors).    Turned the tank on its side, injected MEK and capped off with vacuum caps.  Let it sit while sanding parts for the Fuglyone, then used the drill with speedo cable.  Took somewhere around an hour per side but crossovers are clear   Many thanks for all the suggestions

[calj737]

Might want to flush some gas thru to wash any remaining MEK out

[540nova]

On to the next challenge!


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[ekpent]

 The MEK was a better choice then the acetone, used as a thinner for some of those coatings. Glad you got it done and can move on to the next challenge. Are we gonna get a picture of this thing when your done. What was its other biggest challenge so far ?

[MoMo]

Neglect. At work now but I'll post more later


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[MoMo]

Nothing drastically wrong with the bike, other than mismatched carbs,  dry-rotted tires, seized brakes, clogged crossovers, timing way off, etc. etc.  Here are some photos of the "cafe racer".