70 evinrude carburetor question

1995 70 evinrude.Have read a couple of previous posts of 70 rudes running inherently lean on #2 cylinder.one post said to change air jet from a 54 to a 53.Some said it would lead to inevitable cylinder problem if not adressed. how would one determine whether to change this jet or not?presently motor seems to operate well at all speeds.about 100 hrs. or so.does anyone know why any of the 70's would be running lean on # 2 or is this not something that I should be concerned with? don't know how to obtain tsb on my motor to see if a 1995 70 is listed for this condition.any feedback is appreciated.

Re: 70 evinrude carburetor question

I can't answer any of your questions, but if you're concerned about your nr.2 running lean, keep a close eye on the plug and compare it to the others. If it starts looking dry or whiteish gray check here or with your dealer.<br /><br />c/6<br /><br />Hooty

Re: 70 evinrude carburetor question

Good point Hooty.It looks about the same as the other two now.Looks like the primer line discharges to that #2 carb . Maybe those other conditions were somehow related.

Re: 70 evinrude carburetor question

You are on the right track with the #2 carb and the primer solenoid. One problem I found on my 60 evinrude was the maintenance valve on the solenoid was cracked and allowing the #2 card to suck air. The maintenance valve is a red plastic lever with a brass bleeder valve in the end of it.<br />Look for fuel leakeage when you hit your primer.

Re: 70 evinrude carburetor question

It's not that they inherently run lean, it's that they tend to run hot when the engine is lugged. Make sure that the engine is capable of turning 5800-6000 rpm's with an average load (even if you never run WOT). I was told by a retired OMC Engineering Tech about some test they once ran on that engine - he related an analogy to some of those TV-documentaries where you see huge bridges swaying during earth-quakes and such. Lugging an engine creates enormous stresses and he suggested the block can even "sway" (like the bridge in the analogy) a few thousanths - that would do a number on the crankshaft/con rod/piston/cylinder alignment. I don't rememebr the story word-for-word, but it made sense to me and every rig that went out the door was propped to turn the max rpm's. The dealership sold alot of them over the years and the guys who didn't change the propping are still running strong. <br /><br /> Dropping 1 or two thousanths on the intermediate air bleed will richen things up and that will contribute to "cooler" combustion chamber temps. But as previously suggested, you have to keep an eye on things. A conscientious maintenance schedule will go a long way to long engine life. Even if you're not mechanically inclined an occasional inspection under the hood can reveal alot. Finding a qualified and reputable service tech doesn't hurt either.<br /><br />-John

Re: 70 evinrude carburetor question

don't knock this mechanical ability john.

Re: 70 evinrude carburetor question

****,<br /><br />I had no inention of knocking anyone's mechanical ability. The point is/was: even if one is not mechanical, almost anyone can identify split or cracked hoses, fuel/oil leaks, and broken or disconnected wiring etc.<br /><br />If offense was taken I certainly apologize, but since in this type of format, we can't see/hear each others feelings or emotions I would suggest posters not take general statements personally.<br /><br />-John

Re: 70 evinrude carburetor question

I have a '78 model 70 hp Johnson that runs perfect. Has never been rebuilt, just a recent carb kit and run it-- run it hard every chance you get.

Re: 70 evinrude carburetor question

thanks for the input .solenoid valves and lines don't appear to be leaking.motor is propped to turn 6000 at wot.motor is rarely lugged ,only when tooling through no wake zones.will keep an occassional look at #2 plug to see if it indicates lean condition.If one checked my previous post about vro smoking on start-up they'll see that ****'s remark was facitious.

Re: 70 evinrude carburetor question

ob - I don't think you understand John's meaning of "lugged". If your motor will top out at 6000 you will not "lug" it at any throttle setting. If you prop it out to turn 5000, then you are "lugging" it at all throttle settings. <br /><br />Good luck!