was oil fouled, now carbon fouled

[cmattina1]

So, i've been doing some research, but this is has a few different variables so I can't quite pinpoint it.

As I said in a previous thread: I had some BP6ES plugs in, and the left side was all gummed up with oil when I took took it out after 300km (180 miles?). At this time I had the mixture screws OUT 1 1/4. It still had a spark, but I wanted to experiment a bit so, I put in some BP7RES plugs and put the mixture back to factory spec (1 1/2).

The right looks pretty good (bit carbon fouled). However, now the left side looks to be carbon fouled (rather than oil fouled). It still runs fine (good, i'd like to think). The only thing I found a bit odd is when I first start it up, the left carb will pop (both by sound and visually) 2 or 3 times and after a minute or so of idling it doesn't pop any more (the right carb doesn't do anything). There is also some decent backfiring (sputters) as I decelerate, though I have control over that depending on how much gas I give it as I gear down (i'm a new rider, so I'm still refining this skill)

The jets, as far as I know are stock, but the there are pod filters on, would this result in carbon fouled plugs, (having too small of jets)?

Also, perhaps it possible that the plugs were always being carbon fouled, but the left side was covered up with oil, which is now solved by running the bike a bit more (if it was sticky valves or rings).

 

[Purplezinger]

So, i've been doing some research, but this is has a few different variables so I can't quite pinpoint it.

As I said in a previous thread: I had some BP6ES plugs in, and the left side was all gummed up with oil when I took took it out after 300km (180 miles?). At this time I had the mixture screws OUT 1 1/4. It still had a spark, but I wanted to experiment a bit so, I put in some BP7RES plugs and put the mixture back to factory spec (1 1/2).

The right looks pretty good (bit carbon fouled). However, now the left side looks to be carbon fouled (rather than oil fouled). It still runs fine (good, i'd like to think). The only thing I found a bit odd is when I first start it up, the left carb will pop (both by sound and visually) 2 or 3 times and after a minute or so of idling it doesn't pop any more (the right carb doesn't do anything). There is also some decent backfiring (sputters) as I decelerate, though I have control over that depending on how much gas I give it as I gear down (i'm a new rider, so I'm still refining this skill)

The jets, as far as I know are stock, but the there are pod filters on, would this result in carbon fouled plugs, (having too small of jets)?

Also, perhaps it possible that the plugs were always being carbon fouled, but the left side was covered up with oil, which is now solved by running the bike a bit more (if it was sticky valves or rings).

A couple things come to mind. You could have had stuck rings (these sometimes free up as the bike is used more) and now not as much oil is getting past. If this is the case, we now have to looks a fuel mixture issues. But first things first. Backfiring on deceleration is almost always a indication of air leaks. Any and all air leaks have to be corrected/repaired before you move on to jetting.

 

[cmattina1]

So, could the air leak be at the rubber boot connecting the carb to the engine? As in, is that a common spot? and if so, would that make it "pop"? Otherwise, it could possibly be at the valve cover as the tappet cover O ring has seen better days, though canadian mikes is out of stock on those...

Could the air leak explain the plug though???

 

[Purplezinger]

So, could the air leak be at the rubber boot connecting the carb to the engine? As in, is that a common spot? and if so, would that make it "pop"? Otherwise, it could possibly be at the valve cover as the tappet cover O ring has seen better days, though canadian mikes is out of stock on those...

Could the air leak explain the plug though???

Yes, the rubber boots can crack and leak. Anything from the carbs back, vacuum ports and caps, boots and clamps, intake spigots etc, should be checked. The tappet cover and "o" ring cannot cause a vacuum leak. They could leak oil onto the engine, but they would not effect how the engine runs.

 

[cmattina1]

So, to find the leak, all I can figure to do is use the WD40 method and just spray around? Because otherwise, things appear to be okay.

 

[Purplezinger]

So, to find the leak, all I can figure to do is use the WD40 method and just spray around? Because otherwise, things appear to be okay.

With the engine idling I sometimes spray starting fluid in the suspected area. Aerosol carb cleaner (GumOut) also works. I've not tried WD40 to find leaks but it may work.
When you spray with the engine idling, if you hit a leak the engine speeds up (usually).

 

[cmattina1]

deleted...

 

[cmattina1]

I just gave her hell, sprayen and listening and didn't seem to notice any engine changes. I tightened the left side air filter pod and took it for a 10 minute ride. It actually seemed to sputter a lot less. For that matter, when i said backfire, it was a bit of an exageration, and it is more so a slightly sputter when i let off on the throttle fully, accentuated when going down hill.

there may have been a slightly change, definitely not speeding up, but a change in sound when i sprayed this part. I seriously don't know what you'd call it, but i found another pic online and pointed it out in yellow.

 

[XSLeo]

Thats the end of your throttle shaft. There is a seal in there, actually two in each carb. Four total. www.amckayltd.com/carbguide.pdf might help with replacement.
Leo