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pilot jet richening the whole rpm range?
- martijn
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I'm asking because I can not get my vm28 of my kz900 (1200cc) running well without pinging in the 4-8000rpm range. Tried serveral main jets,float heights and ignition settings. Still the 17,5 pilot.
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- bountyhunter
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Does the pilot jet provide feul over the whole rpm range?? and thus richening??
I'm asking because I can not get my vm28 of my kz900 (1200cc) running well without pinging in the 4-8000rpm range. Tried serveral main jets,float heights and ignition settings. Still the 17,5 pilot.
Yes, but as the throttle gets farther open, the pilot jet's contribution gets very small by comparison to what the main jet is putting into the flow.
1979 KZ-750 Twin
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- mark1122
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- Keep twisting it
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do u have any porting done?
76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
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- wiredgeorge
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wiredgeorge Motorcycle Carburetors
Mico TX
www.wgcarbs.com
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- martijn
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I know 28 mm is way to small but I'm not for top peak power. But with these carbs I can maintain the original airbox and air filter (and sidecovers)
Head has not been ported. It did run easily with 28mm carbs 11.000rpm in fourth gear... then it got scary
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- bountyhunter
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At 11:1 compression, you are going to ping on pump gas unless you add some octane booster.Does the pilot jet provide feul over the whole rpm range?? and thus richening??
I'm asking because I can not get my vm28 of my kz900 (1200cc) running well without pinging in the 4-8000rpm range. Tried serveral main jets,float heights and ignition settings. Still the 17,5 pilot.
FYI:
www.batterystuff.com/fuel-treatments/OS6q.html
1979 KZ-750 Twin
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- wiredgeorge
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1. Give you retarded advance curves to tone down the pinging. I think there are 8 curves; 2 or 3 are advanced and 5 or 6 are retarded. You really need to retard the spark.
2. Give you a REV LIMITER - Any KZ engine spinning 11K rpm needs a rev limiter in the event a shift is missed. A bent crank or blown up clutch hub will result pretty quickly otherwise.
wiredgeorge Motorcycle Carburetors
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- mark1122
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As George mentioned there are a lot of benefits with it. it also eliminates the old stock mechanical advancer completely.
Another option is to degree the cams for less advance.Say, 110 lobe centers. this will bring down the compresion and raise the torque curve.
Or install a thicker base gasket.
76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
~ ~ ~_@
~ ~ _- \,
~ (k) / (z)
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- martijn
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I have not been able to test tke kz withe bigger pilot jets. It seems to have a complete electrical failure.
I'll let you know if there is any progress.
Just something about the ingnition. It is not an ignition timing issue. It is not pinging due a wrong timing. Even with 10 degrees full advance it keeps pinging....
That's why I'm looking at the carbs and the suggested intake lobe retarding might be the best to do.
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- Patton
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I was also of thinking retarding the intake cam..
I have not been able to test tke kz withe bigger pilot jets. It seems to have a complete electrical failure.
I'll let you know if there is any progress.
Just something about the ingnition. It is not an ignition timing issue. It is not pinging due a wrong timing. Even with 10 degrees full advance it keeps pinging....
That's why I'm looking at the carbs and the suggested intake lobe retarding might be the best to do.
Even with 10 degrees full advance it keeps pinging.... --- perhaps misinterpreting, but am thinking ignition timing should be set more retarded (i.e., later) than stock timing to reduce pinging. If pinging when ignition timing is set to stock specs, it will ping worse if ignition is advanced ahead of stock specs. Firing before stock specs (i.e., set too far advanced) would be plug firing before the F mark reaches the permanemt timing mark on the case.
Just thoughts.
Good Luck!
1973 Z1
KZ900 LTD
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- martijn
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Today wheater up her was miserable (rain) so no testride. I'll keep you informed. Thanks for your replies!!
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