Affects of longer diaphram spring in carb

[Azgunner]

I installed a diaphram spring that was 1" longer than stock in a 44mm CV carb & ran it for about 45 miles. I was told by the shop I got it from that it was a spring out of a 40 cv carb, apparently not.

Anyways, can anyone tell me what actual affect using a heavier spring (longer spring) pressure is having on the afr or MAP or anything else. I am putting back a "known" stock spring in the carb tonight. The bike seemed to run very good with the longer spring, just wondering what real affects it was having.


Here's my original post trying to find out what the stock length should be.
http://harleytechtalk.net/htt/index.php?topic=11404.0

Thanks.

[Doc 1]

I installed a diaphram spring that was 1" longer than stock in a 44mm CV carb & ran it for about 45 miles. I was told by the shop I got it from that it was a spring out of a 40 cv carb, apparently not.

Anyways, can anyone tell me what actual affect using a heavier spring (longer spring) pressure is having on the afr or MAP or anything else. I am putting back a "known" stock spring in the carb tonight. The bike seemed to run very good with the longer spring, just wondering what real affects it was having.


Here's my original post trying to find out what the stock length should be.
http://harleytechtalk.net/htt/index.php?topic=11404.0

Thanks.

Actually there is a stiff Stock spring and a weaker performance spring available....if one of those is a inch longer chances are some one has stretched it.
The stock spring will deliver more torque in the bottom end because the slide doesn't open as fast keeping the velocity high in the port allowing for better cylinder fill....the performance spring has less resistance on the vacumm slide and allows the slide to respond faster to your input with the throttle grip.
I always found it best to leave the stock spring in the CV carb if installed on a heavy bike like the cruiser...it provides better torque off the line, however the performance spring will benifit a lighter bike with better throttle responce in mid range and top end.
A stretched spring is worthless.
Doc

[mayor]

I had some left over springs in my carb tuning box, so I posted length and diameter information on your original post.  I agree with Doc, if the spring is longer than 5 3/4", some one stretched it and it's worthless...