Evinrude 140 v4 (1987)

nymack66 · #1 06-11-2008, 07:58 AM

Help I need to know the correct plug to use on this engine, Is a Champion QL78YC gap at .30 OR QL77JC4 GAP AT .40 ?
I am currently running QL77JC4 @ 40 and its oiling up really bad.
I also have NGK's BPZ8HS-10 I can use please let me know the correct option or what works best. Thanks

THEFERMANATOR · #2 06-11-2008, 10:35 AM

QL77JC4's gapped at 35 work well for me, but I rejetted mine due to the loading up at idle as well. Try a set of 32's in your idle circuit and stay with your current plugs. The QL78YC's are a longer reach plug, but may actually load up worse as they will be pushed furthur into the air fuel stream. I know I ran them before and they didn't seem to run as well. Also buy your plugs at WAL-MART, there about 1/2 what most places charge.

nymack66 · #3 06-11-2008, 09:19 PM

Thanks Ferm, I will keep you posted on the results. I am thinking about changing my reeds to Boyseen reeds to improve idle and overall performance, your thoughts? Is it something I can handle without loosing my sync etc?

THEFERMANATOR · #4 06-11-2008, 10:04 PM

To replace the reeds you'll have to pull the carbs off and have to re-sync them afterwards. I put BOYESENS back in my 200 I just rebuilt, and will post the on the water improvements(or lack of) later. So far the engine runs SMOOTH on the hose, and starts instantly which is unusual for a fresh engine still loaded with assembly lube and oil. I would try the bigger air bleeds first and stay with the QL77JC4's, my 140 runs ALOT better with the bigger idle air bleeds. Alos make absolutely certain to run 50:1 if your pre-mixing, I tried 40:1 one time but felt like I was in NAM from all of the smoke.