fouling center plug

ejcamaro

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I recently bought an 01' SRX 700 with porting and the head cut down. It will not idle very long without the center cylinder fouling. I need idle to test some electrical circuits for another project I have going on. Should I mess with the air screw? If so, where is it located on the carb. Also, this sled has BR9ES plugs in it. Are those the correct plugs?
 

The air screw is located on the bottom of the carb, and the stock setting for it is 1 1/8 turns i believe. You can try that and work from there.

The plug that Yamaha recommends is br9ecs. This is the plug that i use.

BTW...When you are warming it up, make sure that you do not touch the throttle at all, just keep the sled running flipping the choke on and off until you can feel heat in the exchangers, then it should be ready to go.
 
10-4 on the no throttle warm ups. Anyone see a problem with the BR9ES for the time being, or should I not run it until I get the right plugs? Does turning the screw out lean it or richen it, I can't remember anymore?
 
Some guys report problems with the BR9ES when running long open throttle runs. I personally switched the BR9EYA plugs, and have run them in all kinds of temperatures and made some long wide open runs with them also. Have yet to foul a plug in 1.5 years of running them, I did foul quite a few ECS though when I ran them.
 
I only and would only run BR9ECS plugs in mine.Something must not be right what are you finding in the electrode that is fouling the plug and why only the center one .Ive had my 2001 since new and never fouled a plug and for warm ups once you take the choke off it should idle fine till warm i have never choked mine for more then 10-20 seconds.
 
ej, for the time being, you should be okay using the br9es plugs, but when you are doing trail riding where you will have long wfo runs, the br9ecs would be a very good idea IMO.
 
Well, I'm assuming it is fouling because of incorrect idle screw adjustment. This sled is not stock and has never seen snow since the porting has been done, so I'm expecting it to need some tinkering. As for the BR9ES plugs, I will pul them and replace with the BR9ECS as soon as I can, but I still would like to get it running today with the plugs that I have if it's safe.
 
Go ahead and get it running with the 9ES's it wont hurt a thing, just swap out for the ECS's before you really pull the Hammer! The ECS's have a recessed electrode and ground set up vs. the ES's, they will hold up to the heat much better and run slightly cooler, kinda like like a 9.5 ES :lol:

I have limped home on the ES's in the past with no adverse effects or lean conditions, it mainly WOT that may cause you some trouble. (so I've heard)

I'm sure there are plenty of opinions on the subject here!
 


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