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Random Quote: I dont know nothin about fishin but I can lie as good as any fisherman.
I have been having intermittent idling and starting problems with my 1990 Evinrude 225HP outboards (860 hours) so I decided to try the Dunk decarb procedure since it had been so successful for others that had tried it.
The decarb went fine I used a remote tank and followed the procedure as Dunk outlined. I was able to start and soak both engines 3 times and on the 3rd time they were both still smoking pretty good. After the procedure I reconnected the fuel lines to the main tank and headed back to the dock. I noticed that my port engine hesitated when I pushed the throttle down but I didn't think much about it.
I've been out on the boat 3 times and the port engine has been getting worse and worse trying to get it started and now when you put it into gear it stalls. Today it started hard and stalled almost everytime I put it into gear. It would start right back up and run fine, but as soon as you put it into gear it would stall. Once I got out into the lake I pushed both throttles wide open and the port engine hesitated but the RPM's started to pick up but stopped at 3,000RPM while the throttle was wide open. I backed down to about 3,500RPM and the port throttle was almost all the way down to full and the RPM's started to slowly increase but would only go up to about 4,200RPM WOT.
I fished for a couple of hours and both engines started fine but again the port engine would stall as soon as I put it into gear. I got mad and jammed the throttle down to WOT but it would only go up to about 3,500 RPM, then it bogged down and stalled. From that point on everytime I put it into gear it would stall so I had to come in on just the starboard engine.
Since the decarb my starboard engine hasn't really improved except it may be a little easier to start but it still stalls a lot at slow speed. Now my port engine won't even run when I put it into gear. I haven't checked anything or done anything since I did the decarb, but now I am going to have to try to figure out what the problem is. Could I have screwed something up doing the decarb? Where do I start when troubleshooting the port engine? Should I change the plugs, the fuel filter and the fuel/water separator's? When I change the plugs what should I look for on the old plugs? I'm looking for someone with experience that can give me a step by step list of things to check before I have to resort to pulling the boat. I don't want to pull the boat out of the water for the year as fall fishing is my favorite time of the year to fish.
There is a small red lever where your supposed to run the decarb through. When you unscrew the decarb can from the motor you can turn this lever that activates the choke. I did this once not even realizing it. I would'nt run the engines untill you figure out the problem, a small problem can turn into a big problem on a 2 stroke motor.
you probably didn't do anything wrong, but a lot of times when de-carboning an engine pieces of carbon get caught between the gap in the spark plugs & short them out under load. you're on the right track about replacing the plugs& filters. i had a similar problem but mine was the clear vinyl inner liner of my fuel hose started to disintergate & partialy plugged my fuel filter. good luck,PaPaBear
The procedure I have for a de-carb on a two stroke says to finish everything off and install fresh plugs, I definately would do the plugs and filters. It's an easy place to start. Post back your results.
Could it be that simple? I thought a fouled plug wouldn't fire at all, will it fire when not under load?
Fichtion- I've heard both sides of the decarb argument but I thought, what can it hurt? If I change the plugs and all is good than I'm sure the decarb did nothing negative to my engines...I hope.
you fell into the trap of believing that you need to decarb.
Yeah ... more 'fiction' there ...
Truth is, no 2 OB are alike, even 2 right off the line next to each other from ANY OB maker. One might carbon up and the other might not. The powerheads are formed by casting methods that can vary on the interior finish. At worst ... decarbing won't hurt anything and at best ... you could have added 500-1000 more useable hours onto that puppy.
Don't believe people who tell you otherwise, i.e., that decarbing isn't needed. It may be their experience with their 1 or more engines, but it belies the manufacturer's manuals and noted OB gurus whose experience I value much higher than the typical THT opine.
__________________ [red]MISS TEAK[/red], 25' Parker mod-V Sport Cabin "Life's too short to own an ugly boat ..." www.classicparker.com
Well seeing you ran the decarb out of a secondary tank. More then likely you fouled the plugs with carbon build up. Also the filter might have gotten clogged. With varnish build up the was in the hoses. Change the plugs and regap them. Also change the fuel/water seprator filters.
Could it be that simple? I thought a fouled plug wouldn't fire at all, will it fire when not under load?
Fichtion- I've heard both sides of the decarb argument but I thought, what can it hurt? If I change the plugs and all is good than I'm sure the decarb did nothing negative to my engines...I hope.
Russ
It's that simple. I went through many decarbs without fouling the plugs. This year I ended up with the same results a you. New plugs, and no problems. Running smooooth... Do the plugs. If you still have problems then you can take another step, but you will not need to. Spark plug functioning is not binary (pass / fail). If the plugs build up resistance, they will affect the way your motor works in a BIG way.
Now I will adjust my routine to include the decarb just prior to my annual plug replacement.
A 1990 Evinrude should have the red lever with what looks like the end of a valve stem with a cap. It does say to change the plugs when done but not untill you run all the "tuner" out of it, change the plugs and see what happens.
If I could have used the tire type valve connection I wouldn't have disconnected the main fuel lines. No remote entry to decarb. I wish there was. I have become so close to these engines that I could tell you every inch of them.
I had the same problems with my twin Merc 150's. I decarbed both motors and got the same results as you. I went through 4 sets of NGK plugs (gapless) and it is still not running better. It is going to the mechanic this week. I'll let you know what I find out.
Location: Los Angeles, FL.or Georgia, depends. In Fl now.
Posts: 5,979
Re: Decarb gone bad? What did I do?
Quote:
jigger - 9/3/2007 5:13 PM
Well seeing you ran the decarb out of a secondary tank. More then likely you fouled the plugs with carbon build up. Also the filter might have gotten clogged. With varnish build up the was in the hoses. Change the plugs and regap them. Also change the fuel/water seprator filters.
Check fuel lines for leaks. Retighten.
If fuel lines are over 5 yrs old they become suspect due to sun and flexing.
If it were a leak in a fuel line,he would loose fuel prime all together.Pull plugs and replace.When was the last time the carbs have been rebuild?With junk in the carb bowls breaking loose,you could of passed trash over to the high speed jet.So,if the plug change doesn't work,I would start looking that way after.
If it were a leak in a fuel line,he would loose fuel prime all together.Pull plugs and replace.When was the last time the carbs have been rebuild?With junk in the carb bowls breaking loose,you could of passed trash over to the high speed jet.So,if the plug change doesn't work,I would start looking that way after.
Ding, Ding, Ding......We have a winner!
When I decarbed my used Yammy the first time, it loosened all the crap in the carbs and screwed up the works. Clean and rebuild the carbs, and never let it go too long between decarbing.
BTW, many hours later for me, the motor runs great and I decarb often!
Decarb gone bad? What did I do? 
IGFA Certified Observer
