evinrude 6 throttle linkage

[carlisle]

The linkage on my newly rebuilt Evinrude 6 is rigged such that at WOT, the throttle butterfly is not quite all the way open; maybe an eighth of a turn more to go before the external linkage reaches the stop. Little 12 footer won't quite plane out and would like to get as much out of her as possible. Anyone think that last little bit would make a difference? If so, is there an easy adjustment?<br /><br />Chris

 

[carlisle]

Re: evinrude 6 throttle linkage

Sorry...It's a '65 year model and I believe the model # is 1301 or 1302. It runs and idles great. The plugs are new and as I said, it's rebuilt by a dealer from the prop up. <br /><br />Another question though. I also own an experimental airplane that uses a Rotax 582cc 2 stroke. In that engine with oil injection and electronic ignition, the correct plug appearance is slightly brown on the insulator. Checking this engine's plugs after about 2 hours of stop/go use, they're quite black with liquid oil accumlating. Manual calls for 24:1 mixture. <br /><br />So....Is it running too rich? Can I get by with say, 30:1 mixture? Or, are these older engines just supposed to have the higher oil content?<br /><br />Thanks,<br />Chris

 

[carlisle]

Re: evinrude 6 throttle linkage

Sorry...It's a '65 year model and I believe the model # is 1301 or 1302. It runs and idles great. The plugs are new and as I said, it's rebuilt by a dealer from the prop up. <br /><br />Another question though. I also own an experimental airplane that uses a Rotax 582cc 2 stroke. In that engine with oil injection and electronic ignition, the correct plug appearance is slightly brown on the insulator. Checking this engine's plugs after about 2 hours of stop/go use, they're quite black with liquid oil accumlating. Manual calls for 24:1 mixture. <br /><br />So....Is it running too rich? Can I get by with say, 30:1 mixture? Or, are these older engines just supposed to have the higher oil content?<br /><br />Thanks,<br />Chris

 

[Paul Moir]

Re: evinrude 6 throttle linkage

Your manual is wrong. OMC went to 50:1 on all its engines in '64. 24:1 is the break-in mix for that engine though. Did the dealer replace the piston rings?<br />Your model number doesn't seem right. It should probably start with a 6 ('65 would be #6502). There were no 6hp engines before '65, so the 50:1 mixture stands.<br /><br />I doubt your problems are related to the extra oil. Since your experiencing performance problems, I think may be running rich, or your compression may be low. You would have to have really excessive oil to slow the engine that much. 6hp should make your boat move.<br /><br />Good luck!

 

[carlisle]

Re: evinrude 6 throttle linkage

Thanks...I figured the oil was a little thick! So, if I'm running rich, is there provision for adjusting mixture at anything but idle speed or is it a fixed jet? BTW, the service manual is on the way. My experience with such publications though is that this kind of one-on-one experience is much more helpful.<br /><br />CHRIS

 

[Paul Moir]

Re: evinrude 6 throttle linkage

There's no high speed adjustment on that engine. It's a fixed oriface. I was thinking a badly adjusted float level, or a leaking needle valve. When you pump the primer bulb, does the carb leak any gas? Other possibilities is a leak at the high speed oriface or the high speed nozzle. When they rebuilt the carbs, perhaps something didn't get tightened down.<br />Both plugs' firing end are identical, pointing to a common problem, right? That's why I'm thinking it's the carb.

 

[carlisle]

Re: evinrude 6 throttle linkage

I'm really not even sure I have a problem but if so, I suspect the carb too. Plugs are firing and look identical. No leaks either while running or when priming; i.e. the engine looks sound and appears professionally rebuilt. That's why I suspect this linkage problem and am anxious to see the adjustment when the service manual arrives. <br /><br />Think a 3-bladed prop would make any difference?<br /><br />CHRIS

 

[Paul Moir]

Re: evinrude 6 throttle linkage

3 bladed props are less efficient than 2 bladed. They are better at handling heavier loads though. The 5hp avaliable that year came with a 3 blade prop, with the same pitch and diameter as the 2 on your 6hp.<br />You really ought to be planing off your boat, unless it's made of cement or something is really really wrong with your setup. I regularly plane off a 15' aluminum utility boat with a 5hp.<br />I don't think it's a linkage problem myself, since you should be planing at about 1/2 throttle.

 

[carlisle]

Re: evinrude 6 throttle linkage

I know it'll be in my service man. when it arrives, but you guys are such a good source I just can't wait. If mixture is through a fixed jet at operating speed (everything except idle), does Evinrude make jets with different orfices? I might want to try some experimentation to see if I can get the plugs looking right.<br /><br />CHRIS