Joined Jun 2001
1K Posts | 3+
Berkshire, England
Well, my mind is completely fried on this one so here goes:
It's my 2001 FS650 that has now be de-tuned to stock engine components for trail ride use and therefore needed to be softened off a little bit :?
The only modifications it has is the LX1 cam now but the problem occurred with the 55 cam anyway and I have fitted a 2003 enduro exhaust system.
The problem is that the intake boot keeps on filling up with fuel - so much so that the engine will not run with the boot in place. With the boot removed the bike starts and runs fine barring a slight missfire at 1/4-1/3 throttle which much worsens slightly under load (e.g. 3rd gear compared to 1st). This missfire was death to the running with the boot on.
The following are the things I have already checked:
Cam timing - triple checked, trust me, this is OK, including even a new countershaft cam chain gear to remove excess play in the chain.
Cylinder head has been removed to check valve seals etc. Last time I the valves themselves out of the head was when de-tuning the engine - about 4-5 hours running ago.
Carburettor, been to pieces more times I've slid down the road, including having checked and adjusted the float level. We've been from silly lean jetting to silly rich jetting and just about everything in between.
Spark is fine but since when has the carb. intake boot had anything to do with the ignition?
Instinct stillsays it is either valve timing or carb. - but what exactly?
Any ideas however imaginative would be very gratefully received.
Ta,
Simon
It's my 2001 FS650 that has now be de-tuned to stock engine components for trail ride use and therefore needed to be softened off a little bit :?
The only modifications it has is the LX1 cam now but the problem occurred with the 55 cam anyway and I have fitted a 2003 enduro exhaust system.
The problem is that the intake boot keeps on filling up with fuel - so much so that the engine will not run with the boot in place. With the boot removed the bike starts and runs fine barring a slight missfire at 1/4-1/3 throttle which much worsens slightly under load (e.g. 3rd gear compared to 1st). This missfire was death to the running with the boot on.
The following are the things I have already checked:
Cam timing - triple checked, trust me, this is OK, including even a new countershaft cam chain gear to remove excess play in the chain.
Cylinder head has been removed to check valve seals etc. Last time I the valves themselves out of the head was when de-tuning the engine - about 4-5 hours running ago.
Carburettor, been to pieces more times I've slid down the road, including having checked and adjusted the float level. We've been from silly lean jetting to silly rich jetting and just about everything in between.
Spark is fine but since when has the carb. intake boot had anything to do with the ignition?
Instinct stillsays it is either valve timing or carb. - but what exactly?
Any ideas however imaginative would be very gratefully received.
Ta,
Simon
