Guzzi V50 Cone AIr Filter Upgrade

Hi All,

New joiner, after picking up my first Guzzi, a v50ii, last summer.

I have used the search function to try and identify similar issues, but not found any. Sorry if this has been asked before.

I serviced the bike myself a couple of months ago, and in doing so I have replaced the air filter with the cone filters from Gutsibits. I took it for a run after, it’s power was fine, pulling through all the range and no flat spots. The only problem was constant backfires every time i shut off the throttle, as such I changed the main jets to the 115 recommended on Gutsibits for the cone filter change.

I took it for a run again the other day, and whilst the backfires had stopped, I experienced two problems:

  1. on two occasions, when pulling away from a stop there was a half second of complete power loss when opening the throttle, not so much a ‘delay’ in the delivery, the bike started to move for a second, lost power for half a second (juddered) then kicked back in.
  2. when hitting 70mph if i continued to try and accelerate the revs went up (and quickly) but no further speed increase.

Does anybody know if anything else needs changing or tweaking within the carbs to alter the air to petrol ratio?



1 Like

Other issue with a switch to cones is that there is then no support for the back of the carbs. I’ve chosen to stay with the airbox so can make no there comment on jetting there.

If you have revs rising with no increase of road speed then that might well be clutch slip. That would need some other investigation - initially in the way you have the cable and levers adjusted up.

Yes, I thought clutch slip too.
Does the “white spirit wash” also work on small blocks?
Can remove contamination from plates and splines by pouring white spirit into the clutch through the timing hole.

Yes, I thought the same on the clutch slip.

Thanks all,

Appreciate the advice. I assumed it was an intake issue as the bike was riding/running fine before I changed the main jets.

I will start investigating the clutch.



Make sure you have plenty free play in the clutch cable and the adjuster on the back of the gearbox.
Are you sure it is rising revs and clutch slip rather than just more noise from the induction roar that K & N cone type air filters create? Sometimes I think my Spada makes more noise from the inlet than the exhaust when opening it up wide open around the local by-pass.