Dellorto Accellerator pumps

[phil37]

I really don't see the logic in any of this

I like a nice easy pull throttle and the ability to get off the line a bit sharpish as mentioned before - regards - Phil

 

[2622]

I really don't see the logic in any of this. If they really don't do anything then find out why and fix it !!

The pumps on the PHF Dellorto's are there basically to add a very very small amount of responsiveness on fast throttle openings...without them connected the carbs basically then work like normal slide-throttle carbs... so if set up correctly you would be very hard pressed to notice them not there if removed. Also as Phil and others you get a lighter and crisper throttle action which is way better for street riding anyways IMHO.

Also as Maurice is chasing a flat just spot off idle as I understand it, then would very much doubt the pumps would be the issue as Laverda's typically use 60/2 slides which means that the pumps dont start working anyway until the slide is open 13mm which is near on half throttle or a tad before.... No 2 ramp means opens at 13mm and closes at 23mm of throttle opening.

 

[Paddy]

Good..thats that sorted then, everyone disconnect their pumps I always wanted a SF so now i've pull the plug out of my centre pot on my triple........ sorted  .and a 180 section rear tyre...about 300 Ibs psi should do the trick..And as for saving fuel ? well i just turn one tap on 

 

[bazzee]

Good..thats that sorted then, everyone disconnect their pumps I always wanted a SF so now i've pull the plug out of my centre pot on my triple........ sorted  .and a 180 section rear tyre...about 300 Ibs psi should do the trick..And as for saving fuel ? well i just turn one tap on 

You can also try only half-filling the tank. 

bazzee

 

[beauchemin]

Brett's reply is spot on.  To clarify, a sudden large increase in throttle opening results in a loss of vacuum until the engine speed starts to be commensurate with the magnitude of the new, larger, throttle opening.  This short period of imbalance (between engine speed and throttle opening) causes the mixture to be lean, so the accelerator pump is designed to compensate for this imbalance.

If you don't engage in sudden large throttle openings, then you can disconnect your pumps with impunity!

 

[nick7]

Yes Brett's reply is indeed spot on...the accelerator pumps have nothing to do with the flat spot off idle and will not cure it whatever you do to them...

 

[3patC]

'well i just turn one tap on' so does Nick
I like the pumps, they do work and no I'm not a mechanic.