Hitchcocks Forum

rebored 59 crusader to 40 plus then fitted small valve head because it was the only one I could find with no broken fins fitted new amal carb but seems to run very rich will I need to rejet carb

Is it a 276 Amal carb?

no simon its a 375 15/16 from mine hosts

Hi Crusaderman, I had a lot of trouble trying to get my 59 clipper to run right after a rebore, starting off with 3 half turns of the air screw (from fully closed) I mucked about for ages, then I went to Halfords & they had a Gunson colortune kit. Started with the air screw fully in (warm engine)and I watched as the colour mixture started off at yellow (very rich) and by unscrewing the air screw out very slowly I started to get blue streaks coming into the yellow mixture (starting to go weak)and that's' a good place to start from. Run the bike then check for the light ish browny colour from the plug, then using the colortune again you can take the air screw in or out accordingly.
I know your doing this bike for a friend crusaderman so ask around & see if you can borrow a colortune kit.
Cheers Howzie

thanks howzie will give it a try /its my own bike by the way

Hi Crusaderman, Sorry for the mistake, must be thinking of someone else, had to go up to 80+ with my rebore right bloody shambles it was to. the carb is worn but I had spent a lot off dosh on the wee beast, little lady was doing her nut so to speak, I had all my parts from Hitchcock's so in the end I had to tell the postie to drop the brown packages over the wall next to my shed, she still found out and that's when the fight started but the hospital says I can go home when all the cuts & bruises heal in a couple of days.
Cheers Howzie.
([email protected])

Yes I concur, start with the air screw and wind it in till the idle stops. If it doesn't then your float height might be too high. The carb has three mixture circuits idle mixture screw, needle jet and main jet. These can all be adjusted individually and are best done in order from the idle up. Regular checking of the plug and of course any soot coming out of the exhaust are good indicators without a more sophisticated tool.

thanks howzie and simon /the sun is shining and I long for the open road /with my rucksack full of tools/