Misfire/white smoke 8v71 on start up

[TomC]

Or on a mechanical engine (which he probably has) pull the valve covers one at a time, start it, then push on each injector one at a time-that will tell you which one is dead or acting up. Good Luck, TomC

[eagle19952]

Or on a mechanical engine (which he probably has) pull the valve covers one at a time, start it, then push on each injector one at a time-that will tell you which one is dead or acting up. Good Luck, TomC

i just said that...

[AndyyCoulic]

Started it and drove it today, went for a nice 4 hour drive. I decided to plug the block heater in just to eliminate that possibility. (Its 20 degrees celsius here/68 degrees fahrenheit). Not cold. Started the same with a misfire, but after a minute of low idle and rough idling i engaged the high idle and it cleared up like usual. Drove fine and strong with no issues. So im pretty sure its just a leaking injector.

I found a complete set of jake brakes for my 8v71 for $500 (including all wiring, switches and valve covers, just have to find a rebuild/tune up kit) which i think im buying. So when i install that, ill buy and install all new injectors as well.


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[Barn Owl]

If it clears up and runs fine then I wouldn't worry about it. On rare occasion mine will act up similarly. One blip of the throttle and smooth as butter. I spent a long time looking for reasons to put my spare motor in, but as the years go by I think the old motor will outlast me. My DD mechanic/consultant loves the old 2 strokes and has seen trashed motors run well beyond any rational expectation. His only concern is getting them hot.

[gus]

My 671 always did that in cool weather (below 35F) unless I used starting fluid or preheat.

If it is probably pretty well worn that will add to the problem.

[uncle ned]

Huggy with a complete new engine with about 4 to 5 thousand miles does that. When fired up cold spit shakes and smokes for a minute or two. Then spits a big cloud of black smoke out and settles down to her 500 rpm idle.

makes every on in the campground happy.

uncle ned

[TomC]

Shorting the injectors refers to electronically controlled injectors-which a lot have. But most have mechanically controlled with linkage, racks, etc that have to be physically pushed on. I know, we're splitting hairs, but some here might be wondering what to short out when there are no wires under the valve cover. Good Luck, TomC

[eagle19952]

They called it shorting back in 1968m probably longer...long before ECM's....that's all.

take a screw driver and mash the plunger,with the engine running, lay a big rag over the valve train...

[luvrbus]

LOL call this one a draw DD says hold the plunger down it's like short circuiting a spark plug no joke it is in the book I knew I had heard the term shorting before