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  1. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    this is a reman short block. it is non-vortec, 181 cast heads (supposedly the best non-vortec for marine). it has a qjet, 12 bolt cast intake with exhaust crossover for divorced choke. the qjet came with the 4.3 that was in the boat when i got it. it has been cleaned and rebuilt before...
  2. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    ac delco mr43t
  3. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    i thought about that, too. they are mr43t, which is what's recommended.
  4. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    thanks for confirming with this being a 4.3 and all the horror stories i've heard about detonation, i've been concerned about total timing, but i agree with ya...the plugs are showing timing is looking good. im leaving it there. with them looking lean, that'll get me back to carb. the...
  5. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    yeah, the plugs look lean to me. picture set with multiple shots of plugs and the piston tops as well as i could get them https://drive.google.com/drive/folders/1utOENunwJ3SqC6nYHq_C1BAAJdQHXq2J?usp=sharing
  6. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    i have a qjet on my truck, so i do have experience with them. :) yes, i have it set according to Cliff Ruggles paper that was sent with the rebuild kit. it states 1/2 turn for this model, so that's what i have it set to. when going from lowest-plane-speed (about 2600rpm on the 17p) to wot...
  7. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    im gonna pull them today and look. while they out, im gonna scope the cylinders for s-n-g.
  8. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    hello fellow iboaters...quick update over last few weeks, i found the timing to be set at 1° btdc per omc manual for 87 pump gas, for a total advance of 13° above 2800 talking with my engine builder, they recommend 8-10° base, so i set it to 8° which put total to 20°. we were finally able to get...
  9. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    right, and that is what i was looking for....a bit rich on the truck. just plugged everything back in the boat. verified timing marks on balancer, hooked up shop tach and timing light to check total advance. its currently running ~13° total, all in by 3000 rpm. as it's in between my marks for...
  10. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    i was wrong about the secondary rods i had installed. they were DR, not DP. since i was getting pig rich at wot on secondarys, i changed them to DP and tested again. wot now goes ~10.4 then down to 11.2 video of this run, for those interested. since it's in a truck, the aft does jump around a...
  11. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    next update. im sure i'll get some bs for this, but here goes anyway. i wanted a good way to check the carb and be able to verify it with actual measurements, so i put it on my truck. i have to say, it works better than the qjet i currently have on the truck. idle is 750rpm with 16" and...
  12. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    yeah, it does sound like a limiter, compared to yours. however, there is nothing like that on this mill. the rpm drop was me cutting throttle.
  13. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    UPDATE: took the boat out today to test. got a 4 blade 17p stainless (renegade 176575) in yesterday, so installed it to try first. temp was 89°f and about 70% humidity. time to plane was ~4.1s @ 18mph wot hit 4300 and 34 mph gps (13% slip) sounds like it was bogging, then backfired thru carb...
  14. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    yeah, internals should be quite similar for the 090m block. i've looked at a lot of boats in this size/weight range with the 4.3l. it seems like most of the 1.84 drives use 21 to 23 pitch and the 1.62 drives use 17 to 19. with mine in the middle at 1.76 i should be able to get 4400 or better...
  15. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    Scott, yes, the coupler is for a pre-1986 stringer drive. the couplers changed in 1986.
  16. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    marine shortblock from a marine engine builder in Florida. everything i put in is marine rated. (edit: except for the sla battery for my stereo)
  17. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    i researched the sh!t outta the coupling when i got the new shortblock. it required the staggered-bolt starter, which requires the 14" flywheel, which i didn't have either of...so before i started engine assembly, i had to make sure a 14" flywheel would fit. then i had to make sure the coupling...
  18. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    hey kenny. the base timing of 6° is for 93 octane and 1° for 87. im running 87 non-ethanol (it's cheap and close). pressure is ~7# at 29gph according to my testing. when i get home im gonna post on cliff's site and get some opinions there on this carb. i know it wasnt built right when i got it...
  19. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    hey scott. i hoped you'd see this. :) the boat originally came with a mercruiser 470 and 23p prop. that was gone long before i got it. so my frankendrive is just that. the 800 stringer is from a 3.8 and when i originally got it (in 2011), all the parts were from a 3.8 and would barely run...
  20. Zyen

    Engine, Carb or Prop? need suggestions or ideas please.

    i had thought that too, but everything i've read (on forums with well-respected experts) say that the 4.3 is already on the edge of detonation, and to never set total timing more than 18°. i have a chart somewhere comparing the 4.3 with the 5.0/5.7 and the v6 advance stops at 18°. OMC specs...
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