WOT I could feel way too much fuel at 2.5 turns out and it got almost snappy like it should be at 1 turns out. My plugs just don't make sense. Is my engine not getting hot enough for a proper burn? After that 20 second WOT run I got out the laser temp gun and my cylinders were about 145 and my chamber was only 120 and my headpipe/exhaudt mani was close to 180.
This melt down just might have me stumped..
- Thread starter Roseand
- Start date
It takes several minutes of overly rich running for plugs to get dark. The plugs heat range also make a big difference. A mixture that would turn a #9 black will make a #6 light brown. Generally #8s are the best compromise for skis. Congrats, you are about to be an expert carb tuner.
BruceSki
Formerly Motoman25
- Location
- Long Island
Dude. Idk what your doing. 30:1? Is it an air cooled motor?
40:1-50:1 is just fine from a 650 to a 1400cc Jetski engine.
Used plugs give plug readings much quicker than new ones.
Put that sucker up against the dock and run it wide open while turning the high speed screw in until you get it to scream as hard as possible. Then back it out 1/16-1/4 turn. Go ride 5 gallons of gas like it doesn't matter and quit p u s s y footing through break in. I took my ss865 brand new right out into the ocean and ran 5 gallons of gas through it. You ever see a two stroke dirtbike racer break in a new piston?
Use oem fuel and cooling lines. None of that Tygon garbage. I've seen so many stupid problems from making the engine bay "look cool". Stock Yamahas run for 15 years with dirty fuel filters and owners who run them hard, put away wet in salt water and don't flush. I'm so frustrated reading this thread that I think I am going to unsubscribe.
40:1-50:1 is just fine from a 650 to a 1400cc Jetski engine.
Used plugs give plug readings much quicker than new ones.
Put that sucker up against the dock and run it wide open while turning the high speed screw in until you get it to scream as hard as possible. Then back it out 1/16-1/4 turn. Go ride 5 gallons of gas like it doesn't matter and quit p u s s y footing through break in. I took my ss865 brand new right out into the ocean and ran 5 gallons of gas through it. You ever see a two stroke dirtbike racer break in a new piston?
Use oem fuel and cooling lines. None of that Tygon garbage. I've seen so many stupid problems from making the engine bay "look cool". Stock Yamahas run for 15 years with dirty fuel filters and owners who run them hard, put away wet in salt water and don't flush. I'm so frustrated reading this thread that I think I am going to unsubscribe.
If ive learned anything, its that bruce knows what hes doing. 30:1 is WAY too much oil. remember that in on drop of mixed gas, adding more oil leans out the ski (less gas per drop). Running it up on the dock is a very great way of getting things dialed in quickly. The hood off, tune, hood on, ride, and repeat thing gets very tiresome.
- Location
- amarillo ,tx
Yeah at least 32:1 for first tank, then 40:1 there after what cpt told me to do for break in
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BruceSki
Formerly Motoman25
- Location
- Long Island
FYI I've never ran anything 32:1 unless the label on the engine required it.
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BruceSki
Formerly Motoman25
- Location
- Long Island
I'm @45:1 now. Klotz R50.
40:1 was too sludgy out the exhaust.
40:1 was too sludgy out the exhaust.
Jesus christ give me a freeken break Bruce ski! I was running it richer on oil because I was breaking it in and I wanted to be on the safe side until I got it closer to dialed in. And I completely realize that more oil=leaner!!
I just stuck a piston so I was being more cautious so that didn't happen again... Because it felt right to me when I tuned it strapped down on a trailer in the water three weeks ago, and it ended up blowing up.
This is how I was told to tune your high-speed /main jet by holeshot and I've read it other places too. You want to start rich. The jet that you use should make your ski sputter at WOT when the screw is 2.5 turns out, then you move it in till it rips. And fine tune with a tach to lean it out as much as you can until you stop gaining rpms and then turn in the screw just a little bit so you're rich of peak.
Usually I run 40:1.
I'm doing things right this time okay? No mistakes.
I just stuck a piston so I was being more cautious so that didn't happen again... Because it felt right to me when I tuned it strapped down on a trailer in the water three weeks ago, and it ended up blowing up.
This is how I was told to tune your high-speed /main jet by holeshot and I've read it other places too. You want to start rich. The jet that you use should make your ski sputter at WOT when the screw is 2.5 turns out, then you move it in till it rips. And fine tune with a tach to lean it out as much as you can until you stop gaining rpms and then turn in the screw just a little bit so you're rich of peak.
Usually I run 40:1.
I'm doing things right this time okay? No mistakes.
BruceSki
Formerly Motoman25
- Location
- Long Island
My echo 12" climbing saw runs like a raped ape!
I yanked those stupid plastic caps off that stop you from adjusting the screws. Lean is mean. As long as you know what too lean sounds like.
I yanked those stupid plastic caps off that stop you from adjusting the screws. Lean is mean. As long as you know what too lean sounds like.
speedysprocket
Alex
- Location
- Chesapeake, VA
All you did was replace a piston. Not like you have a new crank in there, which is usually why you run more oil for break in...
BruceSki
Formerly Motoman25
- Location
- Long Island
What we are trying to tell you is this "break in, more oil, etc" is hurting you.
A 2 stroke is as close to a diesel as you can get. There's not much you can mess up if you know what you are doing.
Fill the tank to the top like it's mid season and run it.
A 2 stroke is as close to a diesel as you can get. There's not much you can mess up if you know what you are doing.
Fill the tank to the top like it's mid season and run it.
Your def rich. Your plugs will probably never color at that setting. At least not on the outside rim at the bottom of the threads. Whatever color you would get is washed off by raw fuel. If bet money if you looked down the plug holes, the tips of your pistons are wet. It's exactly like mine. Seems way too rich until the pipe hits and then it rips
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Spot on! Once it's on the pipe it rips with whatever jet I'm using.
- Location
- wi
If you are breaking your engine in the right way, you shouldn't use a synthetic oil like klotz. The rings won't seat correctly. I've been told this by many reputable people that know wayyy more than all of us combined.
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We would not have this thread and you wouldnt have learned anything if your machinist cut your bore just .002" larger to begin with.
I used dyno oil for the first tank, then switched to klotz.
id suggest a mineral oil for the first few tanks. rings usually dont seat after one tank full.
as for your tuning, understand that you high speed adjuster doesnt fine tune your high speed jet, its adjusts 3/4-full in its own circuit. backing it out will add more fuel at 3/4 throttle though, making any issues with the main jet seem minimized till you jet up which will actually correct the problem. if you have a 3/8-3/4 issue its in the high speed jet. Also remember that the low speed adjuster is set once at idle under load and then left alone. its only touched if you adjust the idle stop screw. I know people love to dial these back and forth and then either stick a piston or never get the power their motor can make. Just a FYI.
as for your tuning, understand that you high speed adjuster doesnt fine tune your high speed jet, its adjusts 3/4-full in its own circuit. backing it out will add more fuel at 3/4 throttle though, making any issues with the main jet seem minimized till you jet up which will actually correct the problem. if you have a 3/8-3/4 issue its in the high speed jet. Also remember that the low speed adjuster is set once at idle under load and then left alone. its only touched if you adjust the idle stop screw. I know people love to dial these back and forth and then either stick a piston or never get the power their motor can make. Just a FYI.