Early last year I had a MSD box fail and sent it in to be repaired, as the box was not all that old they sent me a replacement at the nominal fee. My question is, can a box that appears to be running fine, meaning times out steady, runs good at idle and mid range, very little transom soot, lose about 400 rpm at top end?

I had MSD that would not let motor rap over 4400, changed box out & motor then went to 5600. I called MSD & they told me they do not have bad boxes & it was something else causing problem.

Ah MSD

Check with Bobby Daniels...He's the local MSD garu. He may be able to help you

Ah MSD

Check with Bobby Daniels...He's the local MSD garu. He may be able to help you

How old are the plug wires? my 250 hour old wires would be crappy at start up, could max out at 4500rpm by myself with gas so low that when I came into the no wake zone the boat stalled was also 48*. Changed them out with some MagStar wires this spring, starts first time, ran 4950 with 4 people and 1/4 tank earlier today (was 80's today).

I hate to admit this but MSD and some other boxes hate bad plugs its very very common to loose 4 to 5hundred rpm with plugs that look good ,,swap them and let me know ,it really kills them the wires too but mainly the plugs

Plugs are brand new NGK R5671A-7, wires are Taylor Spiro-Pro 8mm and are three seasons old.

Are they new after the box was replaced ??? and the wires are the best made they should be great

please try the plugs ,hope it helps if not please advise !!!!

To run 2 boxes, which wire gets switched? Do you splice the wires with the plug to the distributer together? or just leave them hanging loose till the one box fails?

Dan

MSD has a neat kit switch and dual coil kit for that its easy to wire so you simply flip a switch and change everything ,,pick-up ,,coil,,and box
Or any part of this look on their web page or pm me I'll send you a chart