Interceptor stalling/bad or no idle

[Fletch350]

I took my 2020 interceptor out for it's first decent run this year and developed a problem.I covered about 30 miles of 70mph dual carriageway then small B roads without any issues and the bike was fine.
After parking for a few hours the bike started ok but would immediately stall any time the throttle was released.Luckily traffic was light on my return journey and I made it home ok with just a few stalls.the bike has a mileage of 3k miles and an Enfield service history although is obviously out of warranty.
Today I've cleaned out the relays which were full of grease but not as bad as a scram 411 owned previously and checked the voltage at idle (14.3v).I also pulled the spark plugs which I wouldn't say were fouled were certainly dark almost black.Whats everybody's thoughts on plug colours on the interceptor? Mine gets 75mpg normally and is run on E5 fuel.
The bike is now running and idling again but I've noticed a very minor occasional "blip"on the right hand pipe holding my hands near the exhaust pipes outlets but it's barely noticeable.Any thoughts much appreciated.

 

[Scrapyard Sorcerer]

Hi, I can generally get 64mpg on my interceptor. They tend to run lean out of the factory. Have you checked the air filter? High mpg and sooty plugs needs looking into. I guess the oil level is fine? I run E10 all the time, when the weather is UK warm, (20 degrees and over!) I do get the odd over-run pop from the standard exhaust. Is everything standard? Plugs should be a toast or Teddy bear brown.

 

[USADoug]

Agree that black (sooty?) plugs are not right. Should be light brown. But 75mpg (UK gallons I assume) on E5 is very good. The initial stalls would be the biggest concern. Stale fuel and/or fuel separation during winter layover? I would drain the tank, inspect the inside of the tank with a flashlight and mirror (rust? gum?). Then fill up with fresh fuel. If the problem continues consider replacing the fuel filter. Though it sounds like you no longer have the idle issue. Have no idea what to make of the "blip".

 

[Scrapyard Sorcerer]

It may be, given the high mpg, that the plug colour may be down to slow riding and low engine rpm on high gear. Doing a "plug chop", as we used to call it, after a higher revving run. So higher revs, lower gear, check plug colour.

 

[Dabrakeman]

If the 75 is UK gallons then it's similar to 62mpg US which I consider normal for my bike.

 

[Bikeruk]

Have replaced the relays.
Fitted new bar end mirrors.
Purchased a Tec Bike gear lever, but yet to fit it.
I have since adjusted the current gear lever as it was pointing to far downwards too not quite "Horizonal" and find much easier to operate despite my size 12/13 boot size.

 

[Fletch350]

Thanks for the replies.The bike is standard apart from powerage short exhaust cans.I have ordered some Bosch relays to replace the re originals which were covered in grease in the usual way.
The standard air filter looks new and the fuel was recent UK e5.the bike normally runs very nicely but then I suppose everything does until it doesn't.Will fit the new relays and monitor the situation,my next step if problems persist will be a valve clearance check.sorry but I don't trust many dealers to do this job properly.rather like a previous r.e dealer who had no problem with doing a valve check on a warm engine.

 

[USADoug]

valve clearance check.sorry but I don't trust many dealers to do this job properly

Agreed. No one but me performs checks/maintenance such as that on my bike.

 

[Bikeruk]

Please ignore my post as it's in the wrong thread. It should have placed in the Interceptor 650 upgrade thread.
Have requested Admin to move it, sorry about that.