Carbon build up
 

HI again, yet another question

I was checking my air filter the other day and had a look down the inlet of the top cylinder while I was there.

I noticed that there is a large amount of what appears to be carbon build up on top of the inlet valves, the entire surface that doesn't touch something is covered and it looks quite thick.

What causes this and is there anything I can do about it without pulling the engine apart, eg spray on cleaner to loosen etc? I was recommended an ether based spray on carb cleaner but this atomises before it lands on the valve heads so doesn't seem to do anything.

As usual all advice welcome.

Has it been backfiring and popping throught the inlet? One posibility. Mine was when I got it and the rear cyl had carbon up into the trumpet.

Rgds,

Rob

Hi Rob

It was popping though the inlet recently while I had fuelling problems which seemed to have been related to crap fuel/blocked injector and is now fixed. This was only for about 3 weeks/400 miles so I wouldn't have thought I would get that much buildup in that time.

Hi Rob

It was popping though the inlet recently while I had fuelling problems which seemed to have been related to crap fuel/blocked injector and is now fixed. This was only for about 3 weeks/400 miles so I wouldn't have thought I would get that much buildup in that time.

Update:
 

I sprayed some ether based cleaner down the inlets before I last took the bike out.

Yesterday I pulled the air filter out and had another look and the build up is almost gone, hopefully the last of it will work it's way off over the next few rides. I might try another spray of the cleaner just before I take it out to encourage things.