Hello! I finally have my 1989 150 XR4 running after the rebuild. I did all new rings/bearings and 2 oversize pistons. It has all new electronics except for voltage regulator. I set the timing with a JSRE dial indicator. Set initital pickup to 4 deg and full advance @22 (advance module is removed) The heads had to be cut slightly to get them flat. Running premix 40 to 1 for break in. Oil injection gone.
The noise Im experiencing happens when I go from just off idle into a "punch it" sort of situation. Not full throttle, but what you might do if pulling a skier. Basically just getting on plane quickly. The noise is a "ping" noise. Like dropping a marble in a coffee can. I only hear like 4 or 5 times until it stops. If I'm already at about 3k and I punch it, no noise and it just pushes me into the seat. My assumption is preignition but not sure. If so, how would I stop it as my timing is already pretty conservative and I run 93 octane.
I also think my prop is a bit large as I've only been able to hit 5k but I havent really been trying hard because I'm still in the "break in" period. This is on an 18' bass boat btw and it's stupid fast.
The noise Im experiencing happens when I go from just off idle into a "punch it" sort of situation. Not full throttle, but what you might do if pulling a skier. Basically just getting on plane quickly. The noise is a "ping" noise. Like dropping a marble in a coffee can. I only hear like 4 or 5 times until it stops. If I'm already at about 3k and I punch it, no noise and it just pushes me into the seat. My assumption is preignition but not sure. If so, how would I stop it as my timing is already pretty conservative and I run 93 octane.
I also think my prop is a bit large as I've only been able to hit 5k but I havent really been trying hard because I'm still in the "break in" period. This is on an 18' bass boat btw and it's stupid fast.