i think the hole shot has made up my mind on the lectron....have u ever had any of the throttle stickage like some others have talked about?

 

no stickage, just an irratic idle SOME times, but not an issue for me.

 

Thanks guys, i appriciate all of the helpful input.

 

well the difference on all of them may be very little, the 45 hasn't really been a bad carb for me. no dyno to compare with but several hundred races later not unhappy. the turbo used a fuel injection system and that is the one i would watch before buying anything. ds days should compare several systems. i'm going to put a pair of duals on mine, i think not sure i want to remove the top engine mount, seems i feel more vibration when that mount is loose so if i remove it i'm sure i would feel it all the time.

bigshow what kind of racing do you do? the comp in florence is about 300 ft up hill and getting to third is about it, so quick is good, so that maybe why i'm happy with the 45, quick hole shot is a good thing. the duals might be best at sand mountain think they said the hill is 1200 ft. so some of that might need to be factored in.
when we were at dunefest they had the studder start (msd cdi)on the turbo bike and that was nice for the hole shot.
the fuel injection was adjusted with a computer which , could be some problem on rain days. not sure if it will be a adjust once and ride or if it is a ongoing adjustment.

 

mostly 300ft drags....i talked to gary about the efi but i dont really know if i want to shell out 1500 dollers for a set up i have no knowledge about when it comes to repairs.But all in all its proberly the best option..

 

i'm learning that given time everything gets better and cheaper

 

i wish the lectron would get cheaper in a hurry!!![img]i/expressions/face-icon-small-wink.gif[/img]

 

We've dyo tuned 39fcrs on two different big bore bikes in the last week or so. They are definitely not my first choice of fuel delivery system!

222

 

DSMIKE had two DS650's stock bore, stock stroke, stock valve that made 80RWHP at 10,000RPM and redlined at 13,500RPM. He ran the dual carbs.

I'm running a twin 40mm throttle body. I can't keep off the 11,000RPM limit with stock cams and the lowend doesn't suffer at all, it's much improved, and it rev's fast.

People with dual carbs who have lowend problems don't have them setup right.

48mm is the smallest I'd go with for a near stock DS. one of the biggest restrictions that is VERY OBVIOUS is the stock 2-into-1 intake manifold setup. a 720 will do better with a bigger carb. might be easier to get the flow using a dual carb.

Most people don't understand that a large bore single cylinder motor requires larger intake/exhaust diameters than you would think you need based on a multi-cylinder automotive engine.

for example, a 650cc 4-cylinder streetbike engine has 4 smaller averaged pulses per 4-stroke cycle. a 650cc DS has the same cylinder volume but in one huge short pulse. because of this, for a large bore single cylinder the diameters need to be bigger than for the 650cc 4-cylinder so that the peak of the pulse is not attenuated from restriction.

we are running 0.67 exhaust A/R in the turbos. this may sound huge, but it's not huge at all for the DS. again it is the large bore single cylinder with one short huge pulse that rquires a huge exhaust housing to not hurt torque. the turbo produces 12psi at rest by blipping the throttle. the turbo spools fast. the BOV goes off after closing throttle even at 3000RPM at rest in garage.

 

Nice explanation of the carb / cylinder match Scooby !