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Tuning with an o2 sensor, advice/tips?
- hardr0ck68
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At idle 11.5-12.2 range so it looks like I will be dropping a pilot jet size or two.
At WOT 14.5-14.9 (I went deep into the red a few time while watching the o2 sensor and not the tach! note to self, no MP3 player while tuning!). That makes me think I should go one main jet larger.
Now for the tricky bit, from idle to about 10% throttle I am seeing a perfect 13-13.5, but anything from about 10%-85% I am seeing very lean 17-18 I even got it to hit 20 a few time... these were readings at speed with a steady throttle (not just after I had whacked it open or slammed it closed). So what do you all think? The larger main should help a little, but I will probably need to drop the clip notch or two down on the needles huh? (bummer I just synced the carbs!)
Keep in mind I am only estimating throttle positions, but the results were fairly repeatable.
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- Motor Head
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Pic's?
Sounds like the needle is lean.
What is the set up, on /bike/ Mods/ carb size /altitude/ etc?
Are you doing any plug readings as well?
How about mileage readings or time from A-B?
1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- hardr0ck68
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Carbs vm24 without accelerator pump
Main jets are 117.5
Pilot jets are 15
Clip position unknown
float position was a bit high when I last checked it with the proper tool. So I raised all the floats a hair when I had the carbs off this week; but I have not checked the level with the tool since (The float level tool is MIA). When I find the tool I will re-check.
EDIT: I installed the wide-band so I would not have to look at the plugs. To me that is alchemy I prefer science. However the last set of b8es came out sooty on the outside and white on the insulator. I have not pulled these plugs yet.
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- Motor Head
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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- hardr0ck68
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I can check tomorrow... It is dark and raining out now.
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- Motor Head
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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- hardr0ck68
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Lets assume for tonight all plugs look similar, am I right to say one size smaller pilot, one larger main, drop the clip probably 2 notches, fresh plugs and take it for another ride?
As I understand it the bike should be at about 14-15 at idle and in 13ish everywhere else.
1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- Motor Head
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1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- hardr0ck68
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1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
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- Motor Head
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I'm a mile high and loose around 30% of anything made. An increase in compression or a turbo is needed here, and sea level jetting is to rich. But an average engine will handle more initial and total ignition advance, due to the lower cylinder pressures.
Post up some pic's of your set up/ bike if you can.
1982 KZ1000LTD K2 Vance & Hines 4-1 ACCEL COILS Added Vetter fairing & Bags. FOX Racing rear Shocks, Braced Swing-arm, Fork Brace, Progressive Fork Springs RT Gold Emulators, APE Valve Springs, 1166 Big Bore kit, RS34's, GPZ cams.
1980 KZ550LTD C1 Stock SOLD Miss it
1979 MAZDA RX7 in the works, 13B...
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- bountyhunter
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The needles call the tune in that region. You either need faster taper or shift them up to get a richer profile.anything from about 10%-85% I am seeing very lean 17-18 I even got it to hit 20 a few time... these were readings at speed with a steady throttle So what do you all think?
1979 KZ-750 Twin
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- hardr0ck68
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1977 kz650 c1
bought it because I was told it would never run again...I like to prove people wrong.
Please Log in or Create an account to join the conversation.