TheSamba.com :: View topic - Dellorto 36mm DRLAs- new but leaky accelerator diaphrapms

Wed Dec 05, 2012 5:13 pm

Took apart the dells, cleaned everything - all passageways and replaced with accelerator pump springs and diaphragms with new ones from CB, along with a gasket kit.

However it seems to be leaking around the accelerator pump housing area. The diaphragm is new and the screws are tightened. However, the only difference is I screwed in the pump bar nut alot more since it no longer has mismatched springs and it seems like it was pushing them in more before with the nut with a couple threads showing.

Any suggestions? There was no sealant before, does it need sealant?

I set the float to 5.5mm when the float just closes, meaning just touches but the plunger does not drop in to completely close.

Also the drop open was set to 12mm.

Thanks

Wed Dec 05, 2012 5:42 pm

Check the pump cover, could be bowed due to age/overtightening. If so it can be sanded flat, easy job.

Wed Dec 05, 2012 5:46 pm

could tightening the accelerator pump nut alot more cause the leak?

Cant be the diaphragm, no leaks with the old ones, and used new ones. Right?

Wed Dec 05, 2012 6:01 pm

Maybe the new ones aren't flexible enough to conform to the warped cover, or you have one corner folded over(easy mistake)

I have not had any problems with CB's carb parts, weber or dell, but if the other aspects are ok then you have to suspect maybe they are the problem.

I don't see how the stroke adjustment would break a diaphragm, there are little stops inside the housing that keep it from traveling too far.

Thu Dec 06, 2012 6:19 am

Thanks Modok.

None of the corners were folded over. Tightened down the screws a bit more and backed off the adjustment but for the stroke on both to about 5-6 threads of screw.

If I did not set the float just right, could that cause excessive pressure that only the pump diaphragms would leak?

If it continues I think logically Modok's suggestion of warped cover is what the problem is.

Going to fire her up soon to see if that helped.

Mon Dec 10, 2012 6:16 am

Tightened down the accelerator diaphragm housing screws and no more leaks.

Also backed off the adjustment nut for less of a spray.

Running great!