onesojourner
I use a thumb throttle.
- Location
- springfield, mo
I have put about 2-4 hours on these. do they look ok?
what can you tell me about reading these plugs?
- Thread starter onesojourner
- Start date
SJBrit
Extraordinary Alien
- Location
- Bradenton, FL
It's hard to get a good read off new plugs, but the tan color of the insulator looks good on the left plug in the top picture. The right hand one looks a bit rich. I also detect that you might soon come into money, and that a long trip is in your future....
Is that from a plug chop, or did you just pull them out?
Is that from a plug chop, or did you just pull them out?
Frosty
New York Crew
- Location
- Western New York
only thing is, if you took them out after idling in through a no wake zone in a marina before pulling them out, they will be more oily or loaded up then if you pulled them following a normal ride. Right?
Frosty
New York Crew
- Location
- Western New York
so back to SJBrit's ? did you just pull them out, or did you chop?
- Location
- Amherst NH
Who's to say the bottom isn't lean and he idled in on a lean low jet and the residual oil you see is from a rich WOT ?
SJBrit
Extraordinary Alien
- Location
- Bradenton, FL
Exactly: that's why you need to do a plug chop. It's better to use old plugs too since they take the color better.
- Location
- Clearwater, FL
What if your plugs look great when idling or anthing below mid throttle, but if you do a WOT cut they start to become very white?
I understand that means it's running lean on the top end and I have tried going higher on my mains, but it never ran right.
Right now I am running 70 pilots 135 mains which is exactly what FP says to run with my setup and I also have my screws turned out much furthur than what FP says just to be conservative.
What do you all think I should do. I am usually never on the top end, but just in case I want to make sure I'm not running too lean.
Most people say you can trust FP's recommendations and I'm even on the conservative side so I always thought I would be fine, but after a few WOT cuts and seeing the plugs turn white I started to doubt my jetting specs.
Thanks:biggthumpup:
I understand that means it's running lean on the top end and I have tried going higher on my mains, but it never ran right.
Right now I am running 70 pilots 135 mains which is exactly what FP says to run with my setup and I also have my screws turned out much furthur than what FP says just to be conservative.
What do you all think I should do. I am usually never on the top end, but just in case I want to make sure I'm not running too lean.
Most people say you can trust FP's recommendations and I'm even on the conservative side so I always thought I would be fine, but after a few WOT cuts and seeing the plugs turn white I started to doubt my jetting specs.
Thanks:biggthumpup:
Frosty
New York Crew
- Location
- Western New York
that was my point... either way you can't take a plug reading after idling.
CarFanatic
Fiberglassing Newb
- Location
- Cincinnati, OH
whats the best way, wot run then kill the engine and read? is it always adjust high speed needle then low?
whats a plug chop?
whats a plug chop?
Last edited:
SJBrit
Extraordinary Alien
- Location
- Bradenton, FL
Really, the only reason to read plugs is to check your high end setting, since you can check idle and mid range just by the feel of the throttle response. A typical sequence of tuning is:
Check idle by letting the motor idle for several seconds and then hitting the throttle (I usually do this kneeling in the tray). If it's lean you'll get a "lean hesitation" which is a quick drop in revs that almost stalls the motor. If it's rich it will "bog" meaning it will hesitate like it has a cough and then leap into life. Your looking for a nice crisp pick up.
Then check mid range by doing the same, but from about 1/4 throttle. Same sequence applies.
Finally you check top end by doing a WOT run for 20 to 30 seconds, and then simultaneously hitting the stop button and letting go of the throttle. The goal here is to kill the spark and the fuel flow at the same time so you retain the WOT color on the plugs. Pull the plugs and look at the color of the insulator round the base of the electrode: light tan is perfect, very light to white is lean, dark or wet is rich.
The trick with the plug chop is getting back to the shore without either a long swim, or dying....
Check idle by letting the motor idle for several seconds and then hitting the throttle (I usually do this kneeling in the tray). If it's lean you'll get a "lean hesitation" which is a quick drop in revs that almost stalls the motor. If it's rich it will "bog" meaning it will hesitate like it has a cough and then leap into life. Your looking for a nice crisp pick up.
Then check mid range by doing the same, but from about 1/4 throttle. Same sequence applies.
Finally you check top end by doing a WOT run for 20 to 30 seconds, and then simultaneously hitting the stop button and letting go of the throttle. The goal here is to kill the spark and the fuel flow at the same time so you retain the WOT color on the plugs. Pull the plugs and look at the color of the insulator round the base of the electrode: light tan is perfect, very light to white is lean, dark or wet is rich.
The trick with the plug chop is getting back to the shore without either a long swim, or dying....
SJBrit
Extraordinary Alien
- Location
- Bradenton, FL
How many turns out are you on the high end? To be safe I'd go up to a 140, turn the screw out and tune down from rich. Go back to the 135 if your screw ends up almost all the way in when you're done. I like to have my screws a couple of turms out to give me some adjustment room without having to pull the carbs.
CarFanatic
Fiberglassing Newb
- Location
- Cincinnati, OH
ah! ok makes sense.
Is there a low mid and high needles? I thought there were just low and high.
Is there a low mid and high needles? I thought there were just low and high.
Mark44
Katie's Boss
- Location
- 100% one place
Different oil companies have different additives in there fuels thus making plug readings inaccurate unless you are using the same fuel every time. IMO
Also need to have a trained eye for this.
Also need to have a trained eye for this.
CarFanatic
Fiberglassing Newb
- Location
- Cincinnati, OH
what way do you recomend for tuning?
look at the piston wash on top of the cylinders!
go to a gun shop and get a fiber optic bore light that goes on a mini maglight.
stick it in the plug hole and examine the top of tbe pistons.
search for piston wash to see what they should look like and then tune appropriately.
go to a gun shop and get a fiber optic bore light that goes on a mini maglight.
stick it in the plug hole and examine the top of tbe pistons.
search for piston wash to see what they should look like and then tune appropriately.
I recommend www.mikuni.com
Click carburetors
Click manuals
Click SBN carburetor owners manual
They got excellent tuning info.
onesojourner
I use a thumb throttle.
- Location
- springfield, mo
I didn't chop it. just normal ridding with a 20yrd idle in.
onesojourner
I use a thumb throttle.
- Location
- springfield, mo
well the only reason I ask is some one told me that the ski being from michigan would not be tuned right for me this far south. the ski runs great.