Power arc

Hi again,

I installed a power arc on a complete restoration of a Combat. I am wrestling with the mikuni as you may have noticed on a recent post but my question now is about the Power Arc. Does the power arc need different settings for a Combat vs a standard Roadster given the higher compression and agressive cam?

Regards,

Gordon

To answer your question, no I don't think so.

I set mine up by the book, Statically. The encoder wheel is highly sensitive and I tend to trust it over the timing marks on the primary side even though I have the marks set right. That is to say, I am more confident with the static timing over the strobe with this system. The key is how perfect you can be at TDC when setting up.

don't i remember reading something somewhere that also said the timing light isn't as useful on the power arch because the three sparks?

Thanks for the feeback.

My system seems to be working fine but since I have been having trouble tuning the Mikuni I wanted to be sure the PowerArc was not contributing to the lack of midrange performance.

I set mine up per the instructions and it appears to be working fine. You just have to be sure to follow the starting procedure if you dont want a strong kick back!

Regards,

Gordon

The hi CR 2S cam Combat likes a faster rise than standard and 4 degree's less total advance, mainly d/t detonation avoidance on KS more than WOT help. As its ridable as is and the 3 sparks make idle mixture variations about a non issue I'd try to bump in some advance and see what happens, but as it seems spark related first thing I'd do is follow the earlier Miki carb advice. Could get er warmed up to a good place to put in new plugs then run up to the stumble or blah zone hit kill clutch to a stop and get a sense of rich or lean to change. I've had great performance times on my past single Miki Combat and my buddy has 34 Miki on his '71 that real trouble for my current dual Amal Combat to keep up with. Keep diddling because a right on Combat just pulls harder off idle on no lags til blows its top. Fred or Powerarc can reprogram curve to suit any application but you'd have to tell them your best guess to try or spend a bit more for DIY kit.

Gordon said:

Thanks for the feeback.

My system seems to be working fine but since I have been having trouble tuning the Mikuni I wanted to be sure the PowerArc was not contributing to the lack of midrange performance.

I set mine up per the instructions and it appears to be working fine. You just have to be sure to follow the starting procedure if you dont want a strong kick back!

Regards,

Gordon

Click to expand...

Gordon
Did you get the recent firmware upgrade on the power arc from old britts? It's suppose to help with kickback

Thanks Guys,

I will try to solve the mikuni issue but will call Fred on the upgrade available for the power arc. I was not aware an upgrade to the firmware was out.

Thanks again,

Gordon

power-arc-ignition-firmware-update-t14533.html

luckily i read this just before i installed mine so i shipped it back to Fred first. Very quick turn around on the update.