1979 johnson 85 hp Javelin

[iceman121]

My Javelin used to run good and now it seems to run funny, by funny I mean it wont run past 3k rpms at full throttle and it coughs and sputters and surges under load. I have had the carbs redone new plugs gas new solinoid new gas lines new primer pump any Ideas

 

[emdsapmgr]

Re: 1979 johnson 85 hp Javelin

Check all 4 plugwires for hot spark. A spark checker or inductive timing light are both good test pieces of equipment.

 

[iceman121]

Re: 1979 johnson 85 hp Javelin

I am not too Mechanical, can you tell me how the ignition plays a part in this, the motor was smooth running and starting and it runs like it has bad gas in it. It surges periodically but sometimes it runs super fast sometimes 8mph and sometimes 40mph please help would like to know what parts to replace

 

[emdsapmgr]

Re: 1979 johnson 85 hp Javelin

Weak ignition components tend to fail when the engine heats up to normal operating temps. The ignition system has a stator, timer base, power pack and coils-any of which could break down with age. They are all fairly expensive, so an investment in some testing is worth your while. An inductive timing light put on each plugwire will show flashes. These flashes will show any weak firing, intermittent or even no firings. It can lead to finding the culprit component. Also, this model has two power packs and four coils, all of which can be swapped around to help discover a defective component. A factory manual is a worthwhile investment, as it has a number of electrical test procedures. You can get an original from Ken Cook Co., in Milwaukee. You can see the parts lists for this engine on the web at: epc.brp.com