Forum

[Norm]

I'm putting together a 570 Bullet, hopefully have it running on the weekend and I'm wondering if anybody has any carby setting tips. Thinking of using a 30mm PWK flat slide, or maybe the Micarb initially with big jets. Any thoughts?

[Phil Ashbrook]

I would open the ports up to 32mm , my 535cc classic engine had the valve guide humps flattened down with no problems and after many years of the rattley old Amal MK 1 I have moved on to the Amal concentric MK 2 with the adapter manifold . The first problem I found was the 50mm stud width meant I had to file some metal away so the nuts could turn and I had to remove the rear r/h fuel tank lug and 10mm off the frame lug just so the carb would fit , the MK2 has no tickler just a cold start leaver wich was not anough so I flood it with my hand over the carb for a stroke or 2 , this means the air filter has to be off for starting . My main jet size is 220 with a 45 pilot jet , I'm still tweeking my needle hight and I have a number 3 slide cutaway . there is a smooth bore version of this carb and a bought the compleat alcohol conversion kit for when I find a way if importing a distiller from the states which could make 2 gallons a day if an oil crisis rears it's head but it's a very well made carb and more practical than the Amal T3GP2 that has no tick over screw

[Norm]

Phil,
Headworks have already done extensive work on the head so no problems there and I have a 32mm Concentric I could try and also have 32mm flatslide and was just tossing around ideas as to what might be best. After fitting that beautifull longstroke crank I don't want to mess things up

[Bullet Whisperer]

Hi Norm,
If it helps, I tuned a 500 with a MIKUNI 28 mm carb and opened the main jet out to approx 135 and that worked ok. I put a 34mm MK II Amal on another tuned up 500 job and fitted a 270 main jet in that. I dodged the head steady / tank bracket by angling the manifold face slightly, by putting it in the lathe on the skew. I have never tried any flat slide carbs, though, so I have no info on them, but dare say you should be pretty generous with the jet sizes to begin with at least.
Regards, Paul.

[Norm]

Thanks Paul, big jets to start with was my plan

[Carl C]

Hi Norm, I have run a Bullet 570 for around 4 years and in the last year with a 32mm Amal Mk1 concentric running jets sizes 106 needle, 220 main, 3 slide and top notch on the needle. In the last two weeks I have run a 230 main jet which made running at 65mph over long distances much smoother and the plug colour much to my surprise is almost a dark chocolate brown. Throttling back from high speed I noticed a slight step change in the fueling so I shall try a 2 1/2 slide. Tickover is fine so I plan to leave the needle jet at 106.

[Dampking]

Are you building an AVL570cc? I think heard similar stuff about it but never saw any of these bikes. If that is the case then how are you getting the parts required for it?

[Norm]

Carl,
Thanks for that, exactly what I needed,
Dampking,
Not an AVL this one is a cast engine.The crossbred motor is going to 535 shortly, if my mate ever returns it, worried he is liking it too much