steve

I have a 22 scarab w/ a carbed 454. it was running great the other weekend, but this weekend it was dead. It starts on the first attempt if you have not touched it in a while, but it doesn't run long. After that it spits and sputters, but will never start. Then it will only turn over. I am not getting spark. When it sputters the spark is there, but it is only for a second. I tested the spark on a few wires, and theyt were all the same.

I checked the coil and it reads 1.1 and 10.55 ohms. Is there any way to check the modules. Are they like any automotive setups? By the way the ignition is completely stock. Plus I checked the cap and rotor, very clean. Also I added new plug 3 weeks ago, but it is not getting the spak to the plugs.

Anyone have similar problems. If you need more info or clearification please ask.

Biggus

iTrader: (1)

Check to see if you have 12 volts at the + side of the coil with the key on. If you don`t , check the ignition switch at the purple wire for 12 volts, If you have 12v at the key, you have a bad connection somewhere. I had a similar problem last week with a 242 Formula and it was a bad connection at the oil pressure guage.

Also, if it is a newer boat, it might be the sensor under the distributor cap. I have seen several of them fail this spring and with the same symptoms.

Kurt.

jpclear

Sounds exactly what a friend went through last year. If it's a Merc. T-Bolt, then replace the spark adv. module. No test that I know of other than try another. He went through two of them cause he had a funky ign/start switch. Those things don't like little power interruptions when they are trying to work. This would also be the perfect time to consider whether you want to stay with the stock 24 deg. mod. or go to the 20 deg. HP version. Merc has several different adv. mods. to choose from. --- Jer

steve

I know I have power to the purple wire, but I only tested w/ a light.

razor1115

If you can find/borrow one, Merc's repair manual has a very easy test procedure for all the ignition parts. I don't remember the exact procedure but it will walk you through step by step to isolate the problem (flow charts and all). I used it to test my mag. pick up in my distributor and locate the problem. t was as easy as disconnecting a couple of wires, placing another next to ground, ignition on, and tap the pick-up wire to a ground source to check for weak/no spark. It's been so long ago I can't tell you exactly...good to have a friend whose a cert. Merc mechanic

steve

Is it just for Mercury ignitions, or does it cover more. I'll call around to find it if you could tell me what to ask for. I can always use another manual.

razor1115

It's the factory Merc mechanics manual... the only place I have seen one is in a Merc shop. There are several volumes, like an encyclopedia, that cover all makes/models of merc power plants

eyezlee

I had something similar happen on my Scarab 3 weeks ago. You've tested for 12v at the coil with a test light, now get a grounding wire with clips, ground the one end somewhere, pull your coil wire off and put a screwdriver inside it. take the opposite end of the grounding wire and strike the green/white wire on the backside of the distributor (with key on). you should see spark, if no spark look to the ignition module mounted on the exhaust riser. pop it out and back in. mine was just loose, when I squeezed it, it popped back in place about 1/8 of an inch. I have since used some slicone on the connection to keep it from happening again.

steve

I just did that. I have spark out of the coil, and I have power coming from the module. I figure it has to be the distributor sensor. It is the only thing left.

steve

I put everything back together without changing anything and now the thing runs great. Hopefully it was just a bad connection. Glad I didn't run out and buy the sensor. Now for a test run, hopefully I don't have to padlle back.