Rocket Man Is Having A Performance Issue?

Headed out

I suppose with a name like Rocket Man, one may not want to admit you have a performance issue. I mean, just think about baseball, or your dead grandmother and you can at least be called Slow Ride man? Just say’n. Anyway, all kidding aside, long time fellow Woody boater Mark Bigda, couldn’t handle the Pepto stories anymore and is taking one for the team and asking a question of the peanut gallery. Just like its summer and he could actually do this work…  So.. Take it away Mr Rocket man.

Headed out in Warmer days!

Timing is Everything or A Performance Issue

Okay so I am having a performance issue. I would love to get some of those little blue pills and pour them into the carburetor and fly around the lake for four hours (any longer and I have to call a doctor) but that probably won’t work here.

Ready to go

My KL is actually having the issue. She starts right up every time, idles and runs great up to 2400 RPMs and then it happens when I try and go faster – the dreaded pinging. Ugh. I have gone through the motions to no avail. My carburetor was professionally restored, new fuel tank lines etc. Pertronix 12V ignition. Now the timing. I have tried every possible adjustment under load and I get the same result. I either cannot get over 2400 RPMs or I get pinging.

Everything look okay from here
I have also played the prop game. I started with the 12 x 14 that came with the boat. I then tried a stock ACME but that hit my strut. I then went to the prop on my hull card 12x 13.

New prop

ACME prop – ouch
Is this a common issue ? Is it a design flaw of these engines ?
Now I had one more thought – the distributor. In the bottom of the distributor are weights and a set of springs. They are supposed to shift at higher RPMs to adjust the timing and prevent the pinging. What if they are not doing their job ? I cleaned everything up in there and nothing changed. Well I should find out soon as I have sent the distributor off to be tested on – a distributor tester.

Is the problem in there ?

Any opinions ?



34 replies
  1. Larry FORGET
    Larry FORGET says:

    I would keep looking along the spark path, with the small black COIL.. or the wire TIPS connectors going into the top of Cap.. Did a helper switch a few wires on the top of cap and you no longer have the correct fire Order.? Plug # 1 may be in time, some got changed.. Or even the black wires are getting older , not strong spark.. With running pull one plug wire at time and should notice slight reduce in RPM on tach.. If no reduced idle , then that wire is bad. . I had all these symptoms on various cars.

  2. Robert
    Robert says:

    Get rid of the Pertronix as I had great difficulty with my 52 Riviera 18′ and my problem went away. The company sent us a second one and still no good.
    Let me know how it goes.

    • dreed
      dreed says:

      I had the same problem with the Pertronix as you are describing. I ditched it last year, went back to old school, and the problem went away.

  3. Flash
    Flash says:

    Pinging is predetonation, or preignition, and caused by several possible issues. Too little fuel, timing too advanced, or carbon buildup in the combustion chamber. Do you have a heavier spring for the distributor advance? That will keep timing the same at lower RPM’s, and back it off at higher RPM’s. It’s a centrifugal advance, so the faster it spins, the farther advanced it goes, at least until it hits a mechanical limit such as spring length.

  4. Captain kapok
    Captain kapok says:

    Use the kiss method, keep it simple. Does the carb have have a fixed jet or high-speed adjustable? What ever it has remove the jet or plug and also th throat drain and use a white rag to catch what ever comes out, I would use a carb cleaner to back spray into the carb to “wash out” what ever is in there. It sounds like there some foreign object that is causing a blockage during high Vacuum.thats my input, on a side not if you take your distributor cap off and try to turn your rotor slightly, if it springs back the mechanical advance is working. Keep us in the loop we’ve all been there.

  5. Flash
    Flash says:

    And yes, many ACME props will hit the struts on classic boats. They have a greater surface area, and therefore, the trailing edge is further from the hub. Chris Craft didn’t allow for much clearance on many models. I only had about 3/8″, so couldn’t use an ACME.

  6. Dan T
    Dan T says:

    Other possible causes of pinging are vacume leaks, wrong carb jets, and bad fuel. I’d start with timing and go from there. Its not a design flaw or the prop.

  7. David
    David says:

    I would also highly recommend you get rid of the Pertronix, or at least switch it out temporarily to test. After several years of problems, I finally switched back to points, and problem completely solved. I have talked to several engine guys since and every one of them says to ditch the Pertronix. Nothing but problems since they shipped them offshore to be made. The difficulty in diagnosing problems with the Pertronix is it isn’t a consistent problem for every one. I changed out mine three times and had problems with all three. Problem was, each one caused a different problem. So, it leads you to think it is something else.

  8. Doug in Maine
    Doug in Maine says:

    I have Pertronix in my ’48 tractor and my ’65 Ford in line six in the boat and they both work great. Try a higher octane fuel. I had pinging in the boat and switched to 93 octane on the advice of my engine guy. No more ping.

  9. John Rothert
    John Rothert says:

    gwad almighty! All these suggestions are good….but doesn’t is amaze that there can be SO MANY possibilities? I have been there and done that for years and I know the end feeling: you just want the damn boat to run right. I like to mess with challenges like this one…but as I have gotten old…so has my desire to mess with this stuff. Good luck. my humble?….ditch the petro…..the electronic…then look to the petro…the liquid.
    John in Va.

  10. Matt
    Matt says:

    HAHAHA! Internet engine diagnostics are the best. Like searching for a cold remedy and finding out you may have toenail cancer. I will say, never knew there was a petronix issue out there. Yikes! I wonder if that has something to do with heating up a coil and thus this issue. Wait, maybe its ethenaul. Ya, thats it, thats what all the mechanics blame when they have to rebuild all the chainsaw and leaf blower carbs.. Hey, its saturday, cold as crap. And this is not a Pepto Bismol story.

  11. Matt
    Matt says:

    BTW, I did not even place this story on Facebook, cause its a train wreck! To thanks Mark, this would have been an easy and good Boat Buzz story, but we needed something! We do have some more fun boat stories coming. Thanks Rabbit for a great one soon!

  12. Ollon
    Ollon says:

    Nobody mentioned it yet but it sounds like your cam shaft is worn. If you try to keep pushing the RPM does it start to backfire? Is it worse under load than in neutral? Maybe its just because I enjoy rebuilding engines and tend not to keep it simple, but after trying everything talked about above on a pinging engine, that’s what it tuned out to be for me. I would remove the side valve covers check your clearances. If they are not opening all the way or you have valves that open more than others as you turn the engine this would be your problem. I’d rather change a cam now than spend half the summer chasing all those other issues around.

  13. Dave Hughes
    Dave Hughes says:

    The internals of your distributor look pretty “rough”…I’d start by disassembling the mechanism – thoroughly clean off the rust – lubricate the moving parts – test the weight of the springs (they must be pretty old now?) and go from there. Overheating coil usually manifests itself with a complete shutdown of the engine until the coil cools off – wherein the motor starts up again. If that doesn’t sort things out and you are certain the spark is good at all rpms’ then move on to the carb (fuel) and work through that system…good luck!

  14. Steve L
    Steve L says:

    I had the same problem with my K motor. I got rid of the Protronix and installed the points and never looked back!

    While many people have success with Protronix in a variety of applications, I think the problem has to do with the small distributor. I’m told that the Protronix is a magnetic switch. maybe its picking up interference from the small body of the distributor?

    • Jerome
      Jerome says:

      I apologize to anyone that likes the Protonics system. But I have purchased them for everything from antique boat engines to stock car engines. Each purchase came with a great guarantee of satisfaction. We consulted with the experts and they were filed in the garbage bin. Give me a good old fashioned polnts system.

  15. Beau in Mays Landing NJ
    Beau in Mays Landing NJ says:

    Years back had my carb rebuilt professionally through a well known reputable Old Time Chris Craft Dealer long story short no power same as you…Installed Wrong Jets in the Carb…then again there is the dreaded fuel tank contamination once you get underway the dirt and worse gets rolling around and sucked into fuel pump and carb ?? Just a couple problems that slowed me down! Good Luck Sorting Through!

  16. Briant
    Briant says:

    No offense, but you could stop beating yourself over the head with a stick and just make a swap to a nice, dependable, powerful Ford 302….

    Our beauty has given us over twelve seasons of trouble free boating fun. Inexpensive tune up parts, loads of torque, plenty of power.

    I know, I know…..not the original. But, do you want to spend your days farting about with a problem, or be on the water, zooming about with family and friends?

  17. Arnie
    Arnie says:

    I had a Graymarine 109 that I put a one step hotter set of spark plugs in. It ran great up to 2500 rpm, but it started pinging and pre-igniting above that rpm. I’d back off the throttle and it quit. I finally put back the original plugs and it ran fine thruout rpm range. I concluded the hotter plugs were acting like a glow plug and caused the problem. No damage was done to the engine.

  18. John Rothert
    John Rothert says:

    I’m liking Arnie’s post and suggestion…..wrong plugs? cheap to try….and like grandma’s chicken soup…it couldn’t HURT.

    and Matt….putting the story on fakebook would not “be a train wreck”……fakebook IS a train wreck…..imho….

    John in Va.

  19. Mark in Ohio(sometimes da U P )
    Mark in Ohio(sometimes da U P ) says:

    I know there is a lot of good knowlagble people weighing in. Here is mine from all In my years of experience. Install proper spark plugs gapped correctly Find the factory specs on timing, get a GOOD inductance timing lite and check and set timing. Is there a resistor on the coil, looks like weights in the Dist are moving properly. Rev the engine without a load (don’t do it long) see if it goes over 2400, take it out on the water, either yourself or someone else determine if its a ping or a knock. There is a big difference. If this does not cure it check the carb. for cleanliness and settings. Good luck you still have several months to figure it out.

  20. Carroll P
    Carroll P says:

    If you recently had it rebuilt, and the compression is too high – due to the head being machined a bit too much – you may need expensive octane boost to stop the ping. That’s the only thing that helped me. It’s expensive though

  21. Larry FORGET
    Larry FORGET says:

    All the comments on carb rebuild,,, there was a good post last week on the outboard forum from a OMC collector where smaller Jets were being sent out if one ordered a complete KIT..! The same part # was being sent in plastic bag if you only order Jet & was correct original size , like 06 thousands bigger than the kit item.!! Supplier had a mixed up inventory stockroom somewhere in country … Something like a 059 new jet is being sent, when original part is 065 . Carpenter says , measure twice , cut once.. or mechanic, measure twice, install once. !

  22. Dana
    Dana says:

    When you check your ignition timing make sure that you also cheak your TOTAL timing. This is your timing at high rpm. A weak spring or worn bushings in the distributor could give the proper timing at idle but allow for to much advance at high rpm. Not sure what the total timing should be perhaps someone else can weigh in.

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