Happy Days
Cadet
- Joined
- Sep 5, 2004
- Messages
- 7
I had my '87 4.3L Mercruiser replaced with a new block with a balance shaft, roller lifters and 4 bbl carb. I'm not sure of the exact configuration because it was a custom job done by a mercrusier dealer. I'm using my old transom plate. <br /><br />Anyway, it runs great but there is a VERY LIGHT spark knock starting about 1500 rpm and it stops at about 3000 rpm. The engine does not miss and has plenty of power. I don't know if I have Thunderbolt IV or V. It appears that the module is mounted on the rear of the distributor.. Maybe the picture will help..<br /><br />
<br />I've tried adjusting the timing but it doesn't seem to help. I wonder if this is normal for these newer engines.