Early (2001) Bonnie Stutter Help Needed

Steamerblue · Oct 14, 2020

My mate has a 2001 carb Bonnie. Nothing special, mostly original, standard equipment and tune. It has a stutter just off tickover which he has spent hours trying to fix.
In the worse situation one cylinder will fail to fire altogether until greater throttle opening occurs - clearly this isn't a great place to be. He has replaced plugs, leads, coils, bought genuine Triumph parts, stripped the carbs, used decent fuel, done just about everything he can to eliminate that small throttle "cough" - the sort you get traversing a roundabout in traffic. You know what he means? It isn't adding to his riding enjoyment.
As he's now at his wits end he would appreciate any info or help from the forum assembly if someone out there has had the same issue and found a solution to cure this problem. Many thanks.

joe mc donald · Oct 14, 2020

Streamerblue
Only thing i can bring to mind is make sure both carbs are in synronised properly and opening and fuelling the same and no sticky needles. Also check for air leaks both carbs and exhaust.
Regards
Joe.

capt · Oct 15, 2020

Look for air leaks in the manifolds, there are rubber caps on the vacuum side that perish , even though they may look okay. These are used to vacuum balance the carburettors.