Well, you can't run on pure seafoam, but you can come pretty dang close. I split the 16oz bottle into two doses. 8oz in the tank and then fill the tank.

 

I didnt mean the full can alone with no fuel in the tank
Just meant a few drops or so with full tank

 

You want it in high enough concentration to actually be able to dissolve any gunk that might be on your injectors/valves. A few drops at a time will not be enough. It has instructions, just go by that if you want to be sure.

For example, you can actually use the vacuum lines to suck it up and it will reach your injectors in a higher concentration. High enough that you will start seeing white smoke come out of your exhaust at a rate that would possibly alarm people if they didn't know that is supposed to be happening. This method can be dangerous if you try to add it too quickly though, as you could hydrolock the motor and bend rods and other fun stuff.

 

I've been using Motul fuel system cleaner for a few years, not constantly, just after any downtime like winter.

I've heard good things about seafoam, nice to know we can get it in the UK, thanks for the info

 

I've only used it in cars. Poured it very slowly into a vacuum hose and got a bit of white smoke out the rear. I didn't get nearly as much white smoke as others seem to get which I hoped was a good sign. I put half a bottle into the tank once too but didn't notice any effects.
At best it cleans some of the carbon buildup and at worst it's just another placebo product.

 

It has three major uses as far as I know, I believe it says to use 1/3rd of the can via each method.

1. Put it in the gas tank as a fuel system cleaner/fuel stabilizer. It will help to keep your injectors/valves clean, but won't fix severely clogged or broken parts, obviously. Don't hope it will fix a non-running bike by just pouring it in the tank.

2. Pour it down a vacuum line like AF4ik mentioned. The purpose behind this is to clean valves, pistons, and the combustion chamber of carbon. It does this job pretty well and usually makes the engine run noticeably better, if it was dirty to start with.

3. Pour it in the crankcase to clean sludge buildup. This is the method that I don't see much success with. Oil changes at the proper interval will stop this from happening in the first place. I definitely don't think it's a good idea in bikes, because I don't know if it plays nice with wet clutches, and because sludging usually isn't a big issue in motorcycle engines.

As a fuel conditioner I see it as pretty useful, and it's a good carbon remover. You'd probably be better off using an actual fuel stabilizer (Stabil, Star Tron, etc.) for long term storage.