My stock 2007 runs well and I push it hard. I pulled the plugs the other day and noticed that the ground strap was very white. I know we run lean per factory spec, but Im wondering if it's too lean. Wondering if I had bad tank of gas, I replaced the plugs and tested them again. Below are the steps and pics. I appreciate any feedback, and I'm not interested in re-jetting, I just want to be sure it's not so lean that it could damage the engine:

1. Warm up the motor, kill engine, install factory DPR8EA9 plugs, air filter is clean
2. Start the engine and red line through all gears up to 4th gear (I didn't have the runway to take it to 5th)
3. Hit the kill switch, pull in clutch, with throttle still wide open.
4. Pull plugs

Here are the pics, "old" plug are the plugs I put in 1000 miles ago, "new" are new. Right/left side look pretty much the same:
http://imgur.com/IVu1Z4u

You can take a bone stock 07 and go up to a 20 pilot from the 17.5 Pilot and go up to a 132.5 from the 130 main jet. Because Suzuki took something that ran fine and then leaned it out for the EPA in the US to improve it's emissions. Change the pilot and the mains and open up the idle mixture screws to 3 turns out, your bike won't be as cold blooded, your throttle response will improve you will be much happier with it's performance overall. First thing I did when I got mine.

Having said that, stock jetting will work on your bike and allow it to be a senior citizen just the way it is many years down the road, rejetting puts it closer to where it should have been when it came off the showroom floor. 

You said you aren't interested in re-jetting, but the way you describe your riding habits and the look of the those plugs basically requires it.

It isn't hard to do at all.  The carbs are fairly easy to remove, and as long as you are careful not to strip any screws changing the jets themselves is also easy.  Just takes like a half hour in the garage.
There are guides on this site.  Just go for it!  You will be VERY happy with the result.


Do you have any aftermarket exhaust or intake?  Edit:  Nevermind, you did say it was stock.

OK, so if it won't strain the engine as people are saying, I can rejet. I tore the carbs down last winter and cleaned them, so I'll just rejet. I'm curious, how can you tell by my plugs that I ride it hard?

Quote from: Darkstar on May 30, 2016, 07:40:44 AM
My stock 2007 runs well and I push it hard.
2. Start the engine and red line through all gears up to 4th gear (I didn't have the runway to take it to 5th)

This is how we know.

hehehe
i was about to post that same quote