Choke Pulloff - Marine Carb just rebuilt

[5stareventsdj]

Idle runs nice and smooth at 550 rpm. I may do the bushings anyway.

Greg

[429bbf]

greg couple of questions? when did this problem start? did you pull the carb and overhaul because of this problem. this could be a timing advance problem in the dist. or is your cam broke on the secondaries not raising the sec. rods out of the holes to give it enough fuel.when it doesn't run as fast as you think it should. does it act like its running out of fuel.give us a run down on how this all started and someone will have the answer to help you fix the problem. dean

[429bbf]

greg sorry for the questions i didnt see your post on the sept.25. how did the carb work on the old engine? dean

[5stareventsdj]

Hi Dean,

I can't say for sure. I bought my boat in August 2012. Engine failed in September after a couple of miserable outings. Manifolds were bad. I wish I knew then what I know now. It's quite possible the carb was not right then. I did do a rebuild using Cliffs Marine kit. It's running real nice. Since I replaced the motor I've been trying to troubleshoot my WOT problem. Stopped counting the $$$ spent quite some time ago. :-(

It's been better with every step though. I'm just trying to get it right.

Thanks for following up. This is my new favorite forum.

Greg

[429bbf]

greg i hate to ask dumb questions but sometimes you get to the bottom of the problem .did you check the cam timing?maybe the cam is timed wrong.1or 2 degrees .how about comp.?did you get a slug low comp. engine.dean

[5stareventsdj]

greg i hate to ask dumb questions but sometimes you get to the bottom of the problem .did you check the cam timing?maybe the cam is timed wrong.1or 2 degrees .how about comp.?did you get a slug low comp. engine.dean

Not dumb questions at all. Thank you for asking them. I've never checked cam timing. Not quite sure how to do it. I did check compression 150psi on all 8 cylinders.  I will look into checking cam timing. I also haven't used a stop to verify tdc. I will put that on my list of things to learn/do.

I bought the engine remanufactured from a reputable engine builder. I didn't expect I would have to check these things... :-(

Greg

[429bbf]

greg i built a 1970  429 about 11.5 comp ratio.when i did the comp test it tested about 250 .i could burn diesel.to make a long story short i had a (reputable) shop do the the heads .and guess what? 10,000 miles later i had it back apart because he never put hardened seats in like he said he did. and the valves where half way sucked up in the head.just a suggestion go the the shop and find out what heads, pistons ,and cam are in it and the chevy guys on this site will tell you if it 150 hp or 300. with 150 hp it may only rev up to 3800.jmtc. dean

[89SS196]

Did the boat run 4600 rpm before the motor broke?  Maybe your boat has too tall a prop for the motor to turn at the correct rpm.
What is your boat's weight, length and hull deadrise?  These factors all affect the amount of power it takes to propel it.  What is your drive ratio and what is your prop pitch?  If the prop is too tall the motor won't be able to reach correct wide open throttle RPM.
I guess what I am saying is, are you sure the motor is the problem?