# Possible valve sticking **URL:** \ **Category:** All Single Cylinder Guzzis\ **Tags:** stornello125\ **Created:** [19 July 2024 09:12 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691 "2024-07-19T09:12:25Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![garyhowell66](https://forum.motoguzziclub.co.uk/letter_avatar_proxy/v4/letter/g/ba9def/32.png) [@garyhowell66](https://forum.motoguzziclub.co.uk/u/garyhowell66)\ **Post date:** [19 July 2024 09:12 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/1 "2024-07-19T09:12:25Z")
Hello all, I have an interesting problem, my 64 Stornello is unrestored and have been riding it a bit to see what needs doing. I’ve done oil change etc. It rides great from cold but after it has been ridden for about 20 mins it starts misfiring at low revs. If you can get revs up it goes ok, but eventually misfires and won’t rev and stops. I suspect sticking valve? Any thoughts would be very welcome! Also can anyone recommend best source for gasket set and valve spares if needed? ![IMG_20240715_210155176](https://forum.motoguzziclub.co.uk/uploads/default/original/2X/d/d07c70c5c17f5023da176c65c812342ce95fcc93.jpeg) ---
**Author:** ![Phil\_Skinner](https://forum.motoguzziclub.co.uk/letter_avatar_proxy/v4/letter/p/a87d85/32.png) [@Phil\_Skinner](https://forum.motoguzziclub.co.uk/u/Phil_Skinner)\ **Post date:** [20 July 2024 04:05 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/2 "2024-07-20T04:05:27Z")
Hi Gary, you might be right but before opening up the engine I suggest you check the strainers on the inlets of the fuel taps. What you describe could well be a build up of rust and sludge which eventually blocks the fuel flow. Washing the tank out at the same time could also pay dividends. Hope this helps, Phil ---
**Author:** ![garyhowell66](https://forum.motoguzziclub.co.uk/letter_avatar_proxy/v4/letter/g/ba9def/32.png) [@garyhowell66](https://forum.motoguzziclub.co.uk/u/garyhowell66)\ **Post date:** [20 July 2024 17:13 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/3 "2024-07-20T17:13:26Z")
Hi Phil, thanks for your suggestion, I have already done that, plenty of fuel. This problem occurs only when engine is fully hot. Thanks ---
**Author:** ![Don-Spada](https://forum.motoguzziclub.co.uk/user_avatar/forum.motoguzziclub.co.uk/don-spada/32/67_2.png) [@Don-Spada](https://forum.motoguzziclub.co.uk/u/Don-Spada)\ **Post date:** [21 July 2024 18:14 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/4 "2024-07-21T18:14:20Z")
Hi Gary It is quite simple to pop the rocker cover off on a Turismo. It’s only two bolts. I make my own gaskets for the rocker cover. If you find you do need valve spares, then they will probably have to come from Europe, someone like Teo Lamers, Guzzi Retro etc. I can’t see it likely to be a sticking valve. A failing coil or ignition winding could be the cause. Try running it till it’s hot by riding around local to the house and then see if the spark is failing when it starts playing up. ---
**Author:** ![garyhowell66](https://forum.motoguzziclub.co.uk/letter_avatar_proxy/v4/letter/g/ba9def/32.png) [@garyhowell66](https://forum.motoguzziclub.co.uk/u/garyhowell66)\ **Post date:** [21 July 2024 19:46 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/5 "2024-07-21T19:46:00Z")
Hello Don, thanks for all the advice, I’ll assess the spark as you say first. ---
**Author:** ![garyhowell66](https://forum.motoguzziclub.co.uk/letter_avatar_proxy/v4/letter/g/ba9def/32.png) [@garyhowell66](https://forum.motoguzziclub.co.uk/u/garyhowell66)\ **Post date:** [1 August 2024 10:04 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/6 "2024-08-01T10:04:26Z")
Hi Don, I took your advice, it was the coil. Another small issue - when accelerating through the gears, the revs stay up for a bit when coming off the throttle. Also on tickover if you lean bike to left - revs increase and to the right they decrease - any ideas? Thanks ---
**Author:** ![Chris950s](https://forum.motoguzziclub.co.uk/user_avatar/forum.motoguzziclub.co.uk/chris950s/32/43_2.png) [@Chris950s](https://forum.motoguzziclub.co.uk/u/Chris950s)\ **Post date:** [1 August 2024 11:37 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/7 "2024-08-01T11:37:53Z")
It could be a badly routed throttle cable or a sticking carb float? ---
**Author:** ![garyhowell66](https://forum.motoguzziclub.co.uk/letter_avatar_proxy/v4/letter/g/ba9def/32.png) [@garyhowell66](https://forum.motoguzziclub.co.uk/u/garyhowell66)\ **Post date:** [1 August 2024 12:21 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/8 "2024-08-01T12:21:27Z")
I’ve checked if carb slide and needle and that’s not sticking, I suspect float problem too, I’ll have a look. Thanks ---
**Author:** ![Syrup\_Head](https://forum.motoguzziclub.co.uk/user_avatar/forum.motoguzziclub.co.uk/syrup_head/32/15_2.png) [@Syrup\_Head](https://forum.motoguzziclub.co.uk/u/Syrup_Head)\ **Post date:** [1 August 2024 13:43 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/9 "2024-08-01T13:43:46Z")
Hi Gary the dell orto carbs are prone to play up on tickover when you lean them over.The owners of small ducatis fit mikunis to overcome this problem,My ducati has an amal carb which is better than the standard dell orto.I would check for wear of the components in the carb due to age of it. CHeers Syrup Head ---
**Author:** ![Don-Spada](https://forum.motoguzziclub.co.uk/user_avatar/forum.motoguzziclub.co.uk/don-spada/32/67_2.png) [@Don-Spada](https://forum.motoguzziclub.co.uk/u/Don-Spada)\ **Post date:** [1 August 2024 15:38 UTC](https://forum.motoguzziclub.co.uk/t/possible-valve-sticking/18691/10 "2024-08-01T15:38:55Z")
The float mechanism on the carb is very basic, just a point on top of the float that rises up into a recess and hopefully shuts off the fuel. Mine leaked for a while, I managed to pick up a new carb that resolved the problem. I have heard of people dressing the 2 together with some fine polish to help it seal.