# 18 hp briggs no spark ?1984 engine



## timbo (Aug 11, 2005)

this is an 18 twin engine briggs and stratton model 422707 type018301 code 84057412 ok so the 84 is the year would this 84 engine have points ?that could be the trouble as it has sat outside but had no gas in it carb is soaking right now in cleaner ,for the night where could my spark be ??


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## justin3 (Apr 10, 2007)

Your engine doesn't have points just an Ignition module that provides spark for both cylinders. It would be located under the engine cover. If you have no spark, check your ground connection to the module and gap between it and the flywheel .010-.014 should do it. If the engine has sat outside then most likely there is moisture in the Ignition Module and it may have to be replaced it if doesn't work.


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## Restrorob (Dec 23, 2007)

If this engine is on a machine disconnect the black kill wire, It's at the right front of the engine where the plug wires exit. It could be a bad safety or ignition switch.


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## Jake T. (May 5, 2007)

Justin3 is right. The only thing you didn't mention is the spark plug. Did you try another one? It's a real quick test and could save some extra work. j.m.o.

Jake...


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## 30yearTech (Sep 14, 2006)

Air gap setting is .008 -.012" for solid state modules .010 - .014" for Points set ups.

As a general rule most engines manufactured after 1982 are solid state ignition.

The Briggs service manual however states that engines with a type number of 0500 and below have points. If your unit has points they will be located under a cover on the front of the engine just under the intake manifold.


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## timbo (Aug 11, 2005)

*so far to go 18 hp no spark yet*

Thanks guys for the info on my engine as this is the first twin cylinder briggs i have ever owned , i do though have 15 other L head engines single most are cast iron friom 2hp to 16 hp but twins are a different story ask any mother ,a single is a lot easier to work on ...when its all you know like me so thanks alot for the help so far (the plugs are brand new) , .>>>>>is there any test with a ohm meter<<<< for the coil its self ???,im looking at what i can do to get it to run, its mine and any changes will be for the better ,this has compression, more than any of my other engines.. i cant wait to hear it purr , might run a 36 inch sno thrower on the tractor , time will tell and help from you gents will get to run , this is (the site of friends for friends )and has allways had the info close at hand ,its what makes the hobby of small engines ,very exciting ,by helping the newbie with his small engines , the best advice on the whole web , happy to be here timbo


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## 30yearTech (Sep 14, 2006)

If you do have a solid state magneto (magnetron), I don't recommend using an ohm meter on it as even a small amount of voltage can destroy the triggering device and render the magneto useless.

Do as justin3 and restrorob suggested and clean the ground and set the air gap to the magnets, isolate the kill from the tractor and see if that helps, if not then it may be time to replace the mag.


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## timbo (Aug 11, 2005)

*ok no points here*

looked it over very good today no points any place and in thiking that moisture was the problem i bought a new armeture (coil has two plug wires out of it to the plugs and a ground (where is the fireing trigger) <<< MODULE>>>>,if it has no points must be in the coil its self , i dont understand how an engine that has no points can effectively fire two (2) cylinders with out a break in the spark comming off the magneto as the magnet on flywheel passes the coil LEGS a low voltage current is generated ,now i read in a manule a four cycle engine makes a spark every revolution of engine but it is wasted out the exhaust ,


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## 30yearTech (Sep 14, 2006)

timbo said:


> looked it over very good today no points any place and in thiking that moisture was the problem i bought a new armeture (coil has two plug wires out of it to the plugs and a ground (where is the fireing trigger) <<< MODULE>>>>,if it has no points must be in the coil its self , i dont understand how an engine that has no points can effectively fire two (2) cylinders with out a break in the spark comming off the magneto as the magnet on flywheel passes the coil LEGS a low voltage current is generated ,now i read in a manule a four cycle engine makes a spark every revolution of engine but it is wasted out the exhaust ,


The twin cylinder coil fires both cylinders at the same time even though they are only used every other revolution. You are also correct even on a single cylinder the plug is fired on every single revolution of rotation, even though spark is only needed every other revolution.


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## climax102 (Aug 2, 2009)

One of the best engines ever made The only problems I have found that has stopped my 18hp twin Briggs in over 25 years has been:

1. Replaced magneto coils twice
2. Rusted flywheel
3. Metal shavings from cleaning rust gathered in flywheel magnet. This shorts out magneto, and simple fix is blow out with high pressure air.


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## pyro_maniac69 (Aug 12, 2007)

make sure you keep your eye on your oil, they DID have an oiling problem and that was why there are so few left, and they scrapped the design


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