Need some help - Port motor not running
 

Port motor is giving me trouble. It will fire off occasionally, run like complete **** and shut off (if I can even get it to fire). I am an old school setup - thunderbolt IV, MSD Blaster ignition coil, single Holley carb setup.

So far I have swapped my MSD blaster, thunderbolt ignition, and carb from one motor to the other with no luck.

Unbolted the MSD rev control box with no luck.

I cleaned the distributor cap the other day - carbs are full and pump gas whe I pump the throttle. No water in the oil or cylinders - I've pulled all plugs and found nothing unusual.

Could I have a ground problem? Problem in my ignition switch(which is a little finneccky)? I do believe one battery to be bad, but I'm using it on ALL battery position to overcome that concern......

Motors only have about 20 hours on them and have run fine up until now......

Thanks for any suggestions.

+12 Volt at coil (key on)?
Are you getting spark at plugs?

..

Hook it up to a test can and try running it. 6 gallon outboard cans work great.

I assume so - timing light is firing so I assumed that it was getting spark to the plugs

After a shut down. Pull a plug to see if wet or dry. Should give you a hint on fuel or spark

Saw you cleaned the dist cap. . If you got some carbon tracking inside the dist cap, it can't be fixed. You'll have to replace the cap. Try swapping dist caps.

I think I am going to replace the cap - I had buildup in each terminate that was close to 1/16th of an inch deep

I have to fix the hatch reservoir first so I can get the hatch up - always something.

Start with the basics. Replace dist caps and rotors.

Change out the sensor in the dist. and check for water in the fuel water separator..

Okay - back to the top, still no luck.

I've replaced the Dist Cap, rotor and sensor underneath with no luck. 12v on both sides of the coil. Put a paper clip in the wire, placed it a quarter inch from the distributor cap and had spark.

I also switched MSD rev control boxes with no luck.

I'm stumped, and frustrated......

I chased an intermittent issue with a key switch, I don't know if you have buzzers or not (this boat did not) and it would intermittently not fire. Out of frustration I jiggled the key and hit the starter switch and it would intermittently fire. Replaced both key switches and then it was fine until the rev-limiter went bad but that only shut the engine down after it heated up, once it cooled down it ran fine. These issues were on a Top Gun, I don't know if the Cafe Racer has the breakers in the cuddy, but you could have corrosion somewhere causing issue. I would try working all the breakers and switches a couple times to maybe break them free or remove/clean/replace.

Since it's the port engine, you could move the cannon plug over to starboard, and see if the issue moves or not. Then you will have an idea if its dash-side related or engine-side related at least. I doubt you have enough slack on the starboard to move it to the port...

This is of course assuming its ignition and not fuel related. Have you tried running it on starting fluid to see if that keeps it alive?

That bad battery could be screwing with you even on 'all.' And remember, only + is thru switch, so bad ground will remain bad ground.

Basics for me after checking if ignition is fine, since a Holley, is to pull it apart and clean every passage and air blead and etc, etc.

If still doesn't start or run right, time to check compression (I don't care if brand new or rebuilt - seen issues with those) and then fuel pressure.

Tbolt IV diagnostics:

http://ww2.justanswer.com/uploads/JA...1_scan0004.jpg

So........

Don't think its fuel - have tons of fuel flow, and have swapped carbs. Definitely doesn't seem to be fuel.

I got it started and after about a minute it started running better, and by about 2-3 minutes it was running fine. I actually experienced similar symptoms over the last couple months the one or two times this happened before. I'm wondering now if the battery voltage is bad and after it builds a little voltage it solves my problem. I'm charging them overnight now, but I'm still not sure because I also swapped batteries.......

Well, same thing today. Barely got it to fire, ran like crap for a minute or two and then cleared up.

I'm thinking of building a machine that just repeatedly kicks me in the nuts - I think it would be more fun than boating......

ever resolve this? I am still ahving the same issue on one of my 525sc's
Ramb