Need some advice from you Evinrude Gurus

[sfc2113]

Well I have to start by saying how pleased I am with my engine. Evinrude made a great prod with this carbed model. I have put 47 hours on it since I got it used in Nov last yr. total hrs is 315. My last comp check in June was betw 100-105 in each cly. not more that 2 psi difference

Other than a few ethenol related problems it runs great, and has kept me in the game all season. But , around the 4th of july, I started noticing that the engine is a little shakey/ bounces a little at low idle speeds 500-1000 rpm. Can hear a slight miss or spit. Only under load in the water put putting in and out of the dock and no wake area. Runs fine on the muffs but that is a different environment for checking an outboard engine. I dont have any issues at high rpm or take off, but it has stalled on deceleration twice after comming off plane recently and the rough idle is getting a little worse but not stalling point.

I have a new fuel system from the tank to the lines, filters ect. no restriction, even ran on a spare tank and same results.

I did a full decarb about 8 engine hours ago using sea foam and high octane gass off a small extenal tank. using dunks method with seafoam: http://www.switchbait.com/forums/showthread.php?t=159

Yes it got ALLOT of carbon out. used the entire gallon mix. Not sure but dont think it has been decarbed ever. there was a ring of crud around the boat.

Put in new plugs after the decarb. Took it for a nice run but it did not resolve rough idle at low speed.

Is ther anything else I should look at fuel wise? or just take it to the pros. I am pretty good mechanically but am mostly a diesel guy. have had my share of 2 stroke onan diesel and gas generator repairs. I could handle doing a carb rebuild myself but am not too good at fine tuning the low idle mixture.

I know the carb rebuild cant hurt and was planning on doing it this fall anyway. I am starting to think it is spark or something in the timing or electrical area. So before I delve in to the time and parts, ect was wondering if anyone here had anything else I should poke at?
Engine Model# e175execd

 

[richie rich]

SFC, I'm not an Envirude owner but have dealt with the same problems with a previous Yamaha 150.......the idle circuit of a carb may have something stuck in it that you won't see at WOT.....and spraying down its throat won't clear it...only a good rebuild, using a ultrasonic tank if you can get one, will get something like that out. That's all my Yamaha service shop uses when rebuilding an old carb. A small pinhole in the diaphram fuel pump may do the same...if you fix the carb, change that as well. You pretty much ruled out the fuel system with all the scenarios you mentioned. An electrical miss at low idle??? Long shot I would think if they are running well at speed. Most "snuffs or sneezes" are usually carb related.

Not sure where you live but the season in many places is on the downside so maybe enjoy the rest ( if you can) and rebuild over the winter.

 

[sharkboy]

I think I have the same problem, but it is with a 15 yr old 150 Evinrude. Believe it or not I got it used with 153 hours, but it hadn't been used but once a year for several years, and I had all sorts of problems that were all solved by a good tune up. Carb clean/rebuild, new fuel, new spark plugs, decarb, etc. Anyway now it runs like a top except when you open the throttle just beyond idle. When hot it will cough and sometimes stall out. I'm going to have it looked at during the offseason but I'll be interested in hearing any suggestions. My guess is an adjustement needed in the low speed venturi valve.

 

[GW VOYAGER]

WEll it's good to know I have a couple of OMC owners on this site besides me.
I bought my used grady with a Johnson 225 and as soon as I joined this site I found out most Grady owners own Yamahas.
No problem just good to know I'm not a loner.

 

[wanderer200]

What year is the motor? Is it smoking a little more than normal and or feels like the choke is partially on? Rebuild the carbs. Possibly a low speed circut plugged.How do the plugs look? any one different (darker) than the rest, check Ign wire and or coil for that cyl. (That would usually appear at higher rpms also.)

I`m an omc guy too. 1983 200 crossflow and now a 2001 200 ficht DI. Except for easy cold-starts and better fuel economy, not thrilled with the ficht. Had the crossflow for 16yrs and got towed once. When it finally blew-up. The ficht for 4yrs, towed twice and 2 or 3 lost trips for alarms and having to abort.

 

[BobP]

Since you are a DIYer, take it in to dealer, hopefully he supports DIYers, tell dealer you want to pay for diagnostics and will do the work yourself other than adjustments (I doubt it's an adjustment).

Did you recently change from regular gas to ethanol?

Any other changess you made?

Does the primer bulb stay normal or collapse at exact moment motor acts up?

Dealer has the test equipment to get it figured out quick. Unlike test equipment, finding good troubleshooters is not so easy.

The carb OMCs are simple designs easy to figure out so not much of a challenge for mechanic.

I'd suggest first, you hook up the clear PVC fuel hose to see if any air is getting into fuel system, if so, same issues will occur. I explained this on other subject thread, for 10 bucks and a hour or so is all it takes. This test will verify fuel system on boat side of motor is normal.

You can have an air leak, and smell no gas or see gas, unbelievable yes, buy true, been there done that. The carbs can not handle too much air, the fuel will foam up in carb bowl and trick needle valve to close early

Make sure hose clamps, and those plastic rachet type clamps OMC uses on the fuel lines under cowl are all snug into and out of VRO pump and carbs, and not cracked.

 

[sfc2113]

What year is the motor? Is it smoking a little more than normal and or feels like the choke is partially on? Rebuild the carbs. Possibly a low speed circut plugged.How do the plugs look? any one different (darker) than the rest, check Ign wire and or coil for that cyl. (That would usually appear at higher rpms also.)

I`m an omc guy too. 1983 200 crossflow and now a 2001 200 ficht DI. Except for easy cold-starts and better fuel economy, not thrilled with the ficht. Had the crossflow for 16yrs and got towed once. When it finally blew-up. The ficht for 4yrs, towed twice and 2 or 3 lost trips for alarms and having to abort.

I did pull the plugs yesterday and they all look ok, they are getting tan in color after about 8 hrs since new after decarb. Most of the plgs have some oil on them , But I did notice that the stb side bottom plug is a a little dryer than the others and slight bit more tan than the other ones.( not burnt). I am going to try to finish out my fluke season Sun-Mon trip then drop it off at the local evinrude shop. Hopefully they can get her back in tip top for the Striper season.

 

[Stonewall]

Don't own a 'Rude but my Son does on his 228. He had the same problem at low speeds. (we do a lot of trolling here in the bay) So he contacted a local guy here who was recommended by the 'Rude factory. He came and checked out the motor and didn't find a thing wrong. However, he did provide one piece of valuable information.....whenever you are running at slow speeds, trim the engine up a bit. The design on these engines allows the oil to pool in the cylinders and not burn off. (poor design - but it is what it is) After a while it affects the performance until you rev it up by getting on plane and burn it off. My Son has tried this and it has really improved his performance. Plus he is not putting in new plugs every 100 hours the way he was before.

Try it.

 

[Simple Interest]

I have twin 1995 200HP rudes. I was given the exact same advice about not running the engines at low RPM's trimed all the way in. Seems to help a little. I still get stalled out from time to time when I put in reverse and apply throttle. I have never treated the engines for carbon build up and have the run the engines at least every other week during season since I bought the boat new in 1996. Perhaps I should run a treatment through the old girls.

 

[sfc2113]

I have twin 1995 200HP rudes. I was given the exact same advice about not running the engines at low RPM's trimed all the way in. Seems to help a little. I still get stalled out from time to time when I put in reverse and apply throttle. I have never treated the engines for carbon build up and have the run the engines at least every other week during season since I bought the boat new in 1996. Perhaps I should run a treatment through the old girls.

If you do the decarb do it in an area not near other boats, I took mine to a ramp in the evening when no one uses it and let me tell you, there was black cud all over the place and a ring around the whole boat when I was finished, If I did this in a dock my neighbors would be PO'ed. Oh and the smoke is lets say, WOW. I am suprised the FD did not come. Was going to do this in my driveway but glad I did not. It would have made a huge mess and neighbors would have called 911 from the smoke.

The decarb did improve the take off performance, I was getting a slight hesitation before the decarb but now it takes off like a batt out a
H***.

 

[JUST-IN-TIME]

every fuel system needs to be checked yearly, fuel lines replaced every 5-7 years


if you drain the carbs after each use, it will help from water sitting in there

rebuild the carbs