95 inch ping

[egstandard]

2004 carbed flht. Did a bore and 95 inch flat top stock compression pistons last july. 2006 stock heads. .030 head gasket. Andrews 26 cams. It pings under load sometimes now. Only when it is really hot outside. Thinking i should have gone with the .040 head gasket? Stock ignition.

[rigidthumper]

Stock curve may be slightly aggressive, but it should be close, as it as designed to be safe/proper for an 8.8:1 engine with a 30° intake close, and you now have a 9.3:1 engine with a 35° intake close.

[PoorUB]

I did a 95" with Andrew's 26 cams, milled the head .030" and used a.030" head gasket plus got it tuned. It would ping occasionally. 

Get it tuned!

[jls 64]

Aftermarket ignition plus  get it tuned

[egstandard]

Like a Daytona Twin Tech?

[1FSTRK]

Like a Daytona Twin Tech?

I had great luck with DTT, all my local builder uses.

[Hossamania]

Like a Daytona Twin Tech?

Yes.

[Hossamania]

I'm assuming the stock cv40 carb, was it rejected, possibly a different needle?

[egstandard]

Yes, it's jetted and running a cvp velocity needle in a cv 40.

[Hossamania]

Next step is ignition, then. The DTT is a good unit. It has manual adjustments that are easily used, and it can be programmed with a custom tune as well.
Putting it on a Dyno would help dial it in and verify that your fuel is correct.

[jls 64]

Ignition fron ultima is cheap.but a dyno tune is need it.

[Y2KRKNG]

A DYNATEK tc2000 would get you where you need to be also. It has preset timing tables on 3 different zones and a rev limit setting. That's it, pretty simple.
If you're not going to "take it to the tuner" at a cost of $1G+tuning devise, then the Dynatek will fit the bill.

[egstandard]

I should also mention that these andrews 26 cams were in the bike when it was 88 inches. Also with a .030 head gasket and the 2006 heads. Never had any ping with that combo.

[Y2KRKNG]

Sounds like the stock timing is serving you well then. Just leave it and use some octane booster on real hot days or a quart of race/Av gas.

[1FSTRK]

I should also mention that these andrews 26 cams were in the bike when it was 88 inches. Also with a .030 head gasket and the 2006 heads. Never had any ping with that combo.

Your compression was lower with that combo.

[Y2KRKNG]

2004 carbed flht. Did a bore and 95 inch flat top stock compression pistons last july. 2006 stock heads. .030 head gasket. Andrews 26 cams. It pings under load sometimes now. Only when it is really hot outside. Thinking i should have gone with the .040 head gasket? Stock ignition.

A little more description would help. You MAY be able to skate by without a new IGN module. Does it ever ping at WOT? Is it only in high gear(4th or 5th) at high load low rpm(below 3k)? Have you gone to a colder plug and smaller gap with the higher compression?

[egstandard]

Never at WOT. Higher load low rpm ping, yes. I'm  not a lugger though. Slow roll of throttle and it usually won't ping. Stock plugs, gapped in the middle of spec. Octane boost does help.

[muskwa]

As Y2KRKNG says, try a colder plug before you spend money on the aftermarket ignition.  I run autolite XS4162 in mine. (2 heat ranges colder than stock replacement XS4164).  An NGK in the 9 heat range would be equivalent.

[egstandard]

I'll look for some of those plugs. What gap you running?

[jls 64]

Try oem 10r12.cheap.two step.cooler.gap..35/.38.

[1FSTRK]

If you are getting ping on a long hard pull the plug may be over heating so the colder plug could help a touch, If you get ping during roll-on or coming into a grade that is pure timing and closing the gap will add timing to an already too advanced curve. If it is ever so slight and only in the hottest weather you could try running maximum plug gap but it would be a long shot.

You have done this build over time making improvements every step of the way, maybe you owe yourself and your engine one more performance step and add the DTT. It will bring out the power from the build you have, be adjustable for anything you may change in the future, and protect your investment no matter what you are running.

[jls 64]

 

[bobo]

If you go for a DTT do not forget the cable so you can fine tune the ignition

[egstandard]

Good point!

[Hillside Motorcycle]

Set the DTT at 1, 2, 2 and 6000 rpm limit for starters, until dyno tuned, if need be.