Hi all, <br />Forgive this long post, an absolute newbie in regards to 2 cycle outboard motors here. Any answers to any particular question of the many to follow are greatly appreciated! <br /><br />So, here we go... <br /><br />Background: <br /><br />My friend has an Avon Redcrest inflatable boat, 8-9 footer (like a zodiac), and it is powered by a 1978? 4hp evinrude 2 cycle, 2 cylinder outboad motor. The motor has no gears (except one of course), 2 blade plastic/composite prop, choke, and a rich/lean dial/knob (apparently used for adjusting the mixture during low/idle settings). The model number is 4806E and the serial number is E0002425. Don't have any literature for the engine. <br /><br />The engines history: <br /><br />They bought the engine second hand when it was about a year old. They then used it for 1, maybe 2 seasons up in the new england states. The boat/motor was used as dinghy for a 20 something foot sailboat, so its doubtful it accumulated many hours in that time. They then moved, and the engine sat in the attic until just a few years ago. Apparently, they put gas in it, and it cranked right up and has run fine since. Its only been run a few tens of hours every year since, and the owner guesstimates that they have accumulated between 50 and 150 hours total in addition to what the first owner put on it. And another thing, since the inflatable is soooo slow with that motor, the motor has probably spent 95 percent of its time at full power. Not sure if that is good or bad, however when I've used it on the inflatable, at least it doesnt sound to me like its over reving.... <br /><br />Now, besides a few scratches, some prop damage, and few rusty screws, the motor, wiring, and plastic stuff under the cover looks in nearly mint condition. <br /><br />The problem and questions: <br /><br />First problem. I used it for a couple of days recently and it started up on the first few pulls when cold, which is pretty good considering I have wirey "girlie" arms and am in wobbly inflatable when I'm doing it. Now, if I stopped the motor, it was pretty darn hard to start right away, EVEN if I tried starting it immediately after stopping it. The motor "throttle" has runs from idle/low to full power/fast, and there is a labled "start" position about 2/3 the full setting. It also has a choke. Now, what would be the proper procedure for an immediate start after stopping. And the procedure for after sitting say 5 to 10 minutes? <br /><br />And being in here in Florida, its almost always hot and very humid, if that matters any.... <br /><br />Now, I could get it started the longer I sat, and if I sat long enough that it was pretty cold it started again okay. And a 5 to 10 minute wait seemed to be enough to greatly increase the chances. Everytime I had shut down the engine it had been running wide open for a long period of time prior to shutting down, as it almost always is.....I'm not sure if it was some kind of heat soak problem or during the dozen or so restart attempts I managed to flood it or something... <br /><br />Now, when we came home, I decided to pull the plugs. The plug metal bodies looked pretty rusty, but amazingly they came out with barely a twist! Both of em! In hindsight, perhaps they were actually loose enough to cause loss of compression (particularly when warm and at the low rpms of a pull start?). But I could see no evidence of "blowby", not that Im sure I would recognize such a thing.... <br /><br />The plugs themselves looked pretty darn good inside. Electrodes good, tan interior ceramic interior element, and center electrodes rounded but not pitted or worn oddly. Probably the original or 2nd set of plugs the engines ever had. Now, there is a paper/plastic label on one spark plug wire that says use a champion L77J4, but the plugs IN the engine were champion QL86C. Would that caused any real problems? And the gaps in the old plugs where nearly .05 inches, which sounds kinda wide to me..... <br /><br />So, any advice/pointers on the plug situation? <br /><br />Now, looking in the engine itself through the spark plug hole, I can see a relatively thin layer of carbon "crust", but some of it can actually be flaked off the top of the piston to reveal the metal underneath, so it sounds like its pretty minor as far as 2 cycles go. Anything else I should look for in there that might be a good or bad sign of things going on? <br /><br />Wanting to give the engine some TLC, anybody have recommendations for safely decoking? the engine? Is there something that can be ran through it while running, or something I can pour in through the spark plug holes and let soak for a few days to a few weeks to clean things out? I thinking it would be nice to make sure that the piston rings are unstuck and remain that way.... <br /><br />I think the engine has been taken care of at least reasonbly well since my friends owned it, though perhaps not babied. The've used good quality 2 cycle oil and gas stabilizer additive (Stab-Bil brand fuel stabilizer), but I dont think they every really prepped it for long term storage or used the stabilizer additive at the high dosages, which it sounds like the least you should do when the gas is sitting around alot and the engine is getting used not many hours per year and goes many months between uses. <br /><br />Anybody got recommendations for a good gas additive/carb cleaner? And what to do when it gets run a few days then is put up again not to be used again for up to six months? <br /><br />And a question about oils....2 things. First, the mixture ratio is recommended at 50:1. Would there be any problems/downsides with upping that a bit to say 32:1? Sure, it would cost more to run it, but it sure would make me feel alot better about the engines longevity...Secondly, whats the BEST oil to use? Again, cost really isnt a consideration considering how little the engine is run per year and how much a major repair or new engine would cost in comparision. <br /><br />Can I compression test the engine? I have a standard car compression tester. Whats the general procedure, and what kinda numbers should I get? <br /><br />Now, the only "real" problem with the engine. The lowest part of the engine, ie the torpedo shapped part right in front of the prop. It has 2 screws for draining and filling with a oil/ lubricant. What kind/brand should I use? <br /><br />And the BAD news about that......I opened those drain plugs when I got home and about the only thing that came out was WATER! The gears probably had a coating of oil on them, but thats about it.....at least I didnt see metal flakes or other odd things come out as well.... <br /><br />How should I flush it out? And after flushing, should I just put in the recommended oil and see if it stays in there? Or should I replace the seals? Would that be hard to do? Would they be expensive or hard to get? And I take it there are 2 of em? one for the vertical shaft and one for the horizontal shaft for the prop? <br /><br />I took off the prop, and that leaves a metal shaft that has a nylon? "disk" (the thing the prop mounts on) on it that appears to be held on by a shear? pin. Can I push that pin out to inspect/replace the seal behind/under the disk, or will I have to remove the small metal plate under the disk as well? <br /><br />And would it be much work to replace the vertical shaft seal as well? <br /><br />Well, thats probably plenty of questions for now.... <br /><br />Thanks in advance for any input! <br /><br />Blll
<br /><br />EDIT: you and BF posted while I was writing this up. <br />The pin should have been stainless steel, but if someone stuck a nail through it it may be rusted in place and tough to remove. I just went through that with my '72 4hp. If that's the case, then penetrating oil and driving the pin with a screw or similair thing is the way to go. I had to go so far as to make a little wooden cradle for the plastic prop hub so I wouldn't break anything while I hammered from the other side. Try not to hammer against the propshaft or you'll risk bending it.<br />The water pump and carburetor rebuilds are niether expensive nor particulairly difficult. Disassemble your water pump before ordering parts so you can find out if you need to get a whole new pump or just an impeller and wear-plate.<br /><br />Here's a nice site for 3/4hp tuneups. Ignore the stuff about the ignition system though - that's older model information:<br />