Timing B50 with X4 Megacycle and STK010 Ignition

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Timing B50 with X4 Megacycle and STK010 Ignition

Post by OrcHero99 » Thu Mar 07, 2019 1:25 pm

Hello everybody

Does anyone of you drive with the STK010 ignition from Electrexworld? How much preignition did you set on your B50?

I drive with the Megacycle Cam X4, have 580ccm and a compression of 10.5:1. I currently have 34 ° but would like to increase to 36 ° or 38 °. Would be glad for a few experiences.


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Re: Timing B50 with X4 Megacycle and STK010 Ignition

Post by HPbyStan » Thu Mar 07, 2019 5:25 pm

Does your 580 have a larger combustion chamber? , if so it probably could use a little more spark lead.

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Re: Timing B50 with X4 Megacycle and STK010 Ignition

Post by koncretekid » Fri Mar 08, 2019 1:25 am

You mentioned that you had welded up part of the combustion chamber and that you have a squish band of .7-.73mm (about .028"), I am surprised that with the 92mm bore that your compression is only 10.5 to 1. So the top of your piston must be chopped or your valve clearances to the piston are quite large. Are you using single or dual spark plugs? Do you see signs of detonation on your plug(s)?

I am running dual plugs, around 14 to 1 compression with a 90mm stroke, and only about 31 degrees advance, but have tried other timings on the dyno from about 29 to 34 with very little, if any, change in hp. Whatever you do, adding a fitting in the exhaust near the head and watching the exhaust temperature with different timings on a dyno may be the best way to determine what will work best (safest) for your conditions.

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