A while ago I posted a message regarding some problems I was having
with my recently bought Gas Gas GT25 Contact '92.

Well, I'm still experiencing some problems... it's all about jetting
I guess.

When I bought the bike, it was running 1/2 regular gas 1/2 aviation gas
with 80:1 Gas/oil mix (Clutz oil). The pilot jet was also changed for
a slightly larger one (an upgrade of '5' was apparently done, but the
owner could not confirm that....)

I decided to run the bike with a different setup. Richer ratio,
something near 64:1, using regular gas only and Golden Spectro oil.
Many people recommended me not to use that aviation gas because of
the lead it contains. Finding it here would have been a problem
anyway so I really want to run the bike on straight gas. Also, the guy
was oiling his air filter with his usual Clotz two-stroke oil... I
decided to re-oil the filter with an appropriate foam filter oil.

All theses changes made the bike run richer, and it is the reason I
assume why it keep on fouling plugs. After not even one tank used, I
have to stop... the plug comes very black. (with the guy's old setup, it
was very rarely fouling plugs, from what he said).

I tried just to give the carburetor more air with the air screw, without
any signifiant change. Does the pilot jet has really something to
do with my problem? Maybe the changes that I've made makes it
necessary to put back the stock pilot jet? (which I don't have...)  I
disassembled the carb and it has a #33 pilot jet right now.

Does someone knows the stock settings/jet sizes for this Dellorto PHBL26
carb? Also, some people tells me about reducing the plug's gap to
prevent plug fouling. Some told me about a 0.02 mm gap. Other tells me
about 0.06mm.  Well... I wish I could find a shop manual for the bike,
but it seems that this item does not exists...

Thanks in advance for any help/advice!

Hugo also known in the woods has "the BPR5ES guy"...