1967 johnson 100 hp

I have a 1967 Johnson 100 hp golden meteor model v4tl-13a. The pulse pack went out a year ago , so I had a boat shop fix it and they got it running and it now has spark,. so I went to the lake to try it out and at idle and half throttle it ran really rough and the hole motor would shake, but at full throttle it ran great then as the day went on it got worse now it only idles and when u put it under a load it does not go runs rough, the plugs load up, I have checked and all plugs have spark. I have played with the timing but not sure if its set right I don't have any specs on it, have check to see if the carb and distributor are synchronized they are with what the timing is set at right now, it wont even reve up. when I run it in a tank I get oil and gas in the water tank, I have tried different plugs, I cant find a boat shop that well work on it so I guess I have fix it my self . lost don't know what to try any help would be great . thanks I do have a 1968 service manual but things are a little different then my motor.

If you have proper compression (100+ psi and even on all cyls) and spark that will jump a 1/4" on that model with a strong blue lightning like flame... a real SNAP!... then look for a carburetor/fuel problem. You're going to need the proper manual for that engine as the carburetor is not for the faint of heart. The float levels themselves can drive you nuts.

However... try this valve setting routine.

(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note 1: As a final double check setting of the slow speed valve(s), if the engine has more than one adjustable bneedle valve as yours does, do not attempt to gradually adjust all of the valves at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.

NOTE: The carburetor has four (4) brass fixed high speed jets... make sure they are perefectly clean!

Thanks joe . Tonight I checked the compression perfect on all 4 cyl had a 100 + on all they were all with in a couple pounds I well continue with what you also posted and let you know what I come up with thanks a ton

As Joe said, that carburetor is not to be messed with unless absolutely necessary. Gaskets/kits are obsolete or hard to find, and $$expensive if you do. Floats require a special tool to adjust.

You said you "messed" with the timing. Well, that sends up an alarm. But nevertheless, the problem might be an arced-through distributor rotor. Or cracked/carbon tracked distributor cap. Or bad plug wires. You can't just assume everything is ok just because it has spark.

Your 68 service manual should have information on the carburetor.---The 67 100 HP is a prime candidate to retrofit a distributor from earlier V-4 motors. Various HP models that have the battery powered points / condenser / coil for much cheaper parts.

Just as a suggestion perhaps, a note of sorts, things I've done in desperation over the years so to speak.........

Some of those four barrel carburetors have a weird spring setup between the float and a hollowed out needle valve that is just this side of impossible to get seated properly. I've found that setup to be a fuel flooding paradise that would drive one nuts.

I got rid of those spring loaded needle valves and installed regular ones (40hp valves if I remember right worked fine), turned the float chamber upside down and adjusted the floats so that the float end opposite the needle valve was just slightly off level (higher) than the other end. When the float chamber was upright and installed, this prevented the chambers from flooding but still provided the correct amount of fuel to flow.

The replacement valves to use... could be that the 40hp models weren't the ones (been awhile). Use a small drill bit to measure the inlet hole of the float needle valve to figure the proper one to use as a replacement.

Ok , I finally had some time to work on the motor again , I set the timing to spec I sync the card and distributor , I checked the high speed tubes in the carb but didn't wont to dig into the carb much because of what u guys posted about the carb , the tubes looked clean . I check spark sometimes I get a good blue spark that well jump a 1/4 and sometimes not . I think it is a spark issue , the engine runs erratic . Is there a vacum switch on this motor ? When I bought the boat it had a perstolite 65 cd box on it . The new box that the boat mech put on it is a prestolite idg 3001A well this cd box work on this motor , all that I can see is he changed out the box and that's it . I think he also changed the pick up wheel under the rotor from a brass one to a nickel one . It still has the pulse transformer on it , with the new box does it need a new kind of coil ?Could it have another bad cd box on it ? I also put new fuel lines on and the fuel filter and pump look clean . Thanks for all the info so far it's been great .