KAD300 Sync problem

Hi
I have twin KAD300 in a Riviera and recently developed a fault where when the engines are in Sync (on EDC), the starboard engine will lose revs for about 1-2seconds. The problem only happens when (a) the EDC Sync is engaged, (b) the engine is reving over 3000rpm and (c) after about 30 minutes of running. When it happens, the Port engines stays at set revs and the starboard will drop say from 3200 to 2900rpm and then 1-2s later get back in sync. It will do it every 2-3 minutes. We have checked the fuel system, swapped over the air intake temp sensor and checked for loose electrical connections. The starboard and port run fine with no loss of power when Sync is not engaged.

Has anyone experienced something like this.

I don't know the details for that engine, and may not have this quite correct, but there is likely a magnetic pickup on the bellhousing or more likely if it is like some other models on the front timing cover. This is your electronic 'rev counter'. If the wire connection on that was loose it could cause your issue.