Pipe Cleaning

[oldjapanesebikes]

Just as a matter of interest - I was surprised at how much carbon and coke (no metal bits thankfully !) that I managed to scrape out of just two pipes for the the #1 and #3 cylinders on the bike I've just finished rebuilding .The two smaller diameter centre pipes had similar amounts, and actually one small pipe I was cleaning while Allan was visiting seemed to be almost blocked solid in one section.



I still plan to have the pipes tanked at some point, but this will do for now. You can see the scraper I made from a bit of flat bar behind the pile. It would be interesting to know how much power loss accumulates over the years with these pipes as the design does encourage drop out across the interior baffles.

[Scorch]

I probably need to do this. I get small, dime sized drops of black oil under my bike, I think it's coming (somehow) from the pipes.

[Craig380]

It's amazing how much stuff does come out. I found on my 380 pipes that the sound-deadening wire mesh on the main chambers of a couple of the pipes had partially detached from its spot-welds and was flapping around.

So I fixed one of those springy "drain snakes" into a drill chuck, fed the snake into the pipe and flailed the insides. Eventually I was able to pull the mesh out through the header pipe ....

There was a detailed article in the UK mag, Classic MC Mechanics, about pipe cleaning. Apparently caustic soda is not as effective as a 50/50 mix of cheap, fresh brake fluid and white spirit. Soda simply saponifies oily deposits, whereas the brake fluid / white spirit mix dissolves & loosens the hard deposits. Haven't tried it myself, however.

[oldjapanesebikes]

There was a detailed article in the UK mag, Classic MC Mechanics, about pipe cleaning. Apparently caustic soda is not as effective as a 50/50 mix of cheap, fresh brake fluid and white spirit. Soda simply saponifies oily deposits, whereas the brake fluid / white spirit mix dissolves & loosens the hard deposits. Haven't tried it myself, however.

I read that article also, and was seriously thinking about trying the same thing myself. Not addressed in the MC Mechanics article though, and the concerns that made me pause were a) to do this properly I think you'd need a pretty big vat or tub just to contain any spills, as the pipes aren't small - the bath tub would be perfect but SWMBO'd had serious concerns about the suggestion b) that's a lot of nasty fluids that you will then need to handle and then dispose of in a safe manner and c) in a residential setting - where and how are you going to be able to rinse out the pipes properly afterwards to ensure nothing ends up in a sewer ?

[Craig380]

You're right, it must be at least 3 - 4 litres of fluid per pipe to dispose of. Maybe the dry scrape / internal flail method is best.

In that same article he'd made a scourer / scraper from an old clutch or brake cable with the last couple inches unravelled and splayed out, which would also work well if you fix the inner in a drill chuck.

[Suzsmokeyallan]

Ian you did get a bundle of stuff out of those pipes indeed, and the baffles can hide a lot of carbon as they have a lot of small creases in the flutes.
I wondered about sand blasting the front and rear sections inside the pipe by attaching a fitting to the front and then to the rear of the pipe to do this process.
This idea should get rid of a lot of the crud at the ends with minimal liquid waste, but then you would still have to stand the pipes up and fill each one with ATF or brake fluid and white spirit and cork the ends to seal them to get at the middle sections.