Yamaha F150 issues

The compression is fine;
#1 145
#2 140
#3 140
#4 145
I did not have the throttle open so that may explain them being a bit low plus all I did was twist it in using the hose might not have sealed real well but consistency was there.
 
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Came back from Sandheads last Sunday and the engine ran really rough not able to get over 4200 rpm. I went to the marina this afternoon looking to find the issue. Had the throttle up around 1800 rpm and started pulling spark plug leads one at a time. Number 1 and # 4 pulled the engine down significantly while 2 and 3 made very little difference. Two and three share a coil so I swapped the two coils to see if there was any difference and non whatsoever.
Any ideas guys. The engine has 550 hours on it and is a 2004. Would it be time for injectors. The engine has always run like a top. I think it was starting to run a little rough going back a couple of weeks after I nailed a log. I was thinking it was a dinged prop and changed it out last Saturday. I guess the timing was coincidental. Might pull it out of the water tomorrow. Any recommendations on a good marine mechanic in Langley?

Thats the it, times up for a Yammi........



Sorry bud had to get that jab in lol
As mentioned I really think you got some bad fuel, I would start with both filters and drain the VST tank.
Injected motors have no sense of humour when it comes to wet fuel, tips can rust in real short order.
 
Those #s are fine and prove its nothing fatal.
I would also fire it up on a portable tank of known good fuel because the fuel in the tank is suspect until you can prove its not a fuel related problem
 
That's originally what I thought,bad fuel, even asked a few people at the marina if anybody knew of any bad fuel recently.Funny thing is I tried to get fuel at the same place I usually do the next time and was turned around as they were shutdown because they had no power. I grabbed it at the other place. Im only half way into that tank of fuel but was having some isssues on the previous tank. I did not see anybody else without power that morning. It's got me wondering now.
 
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Compression is good and even across the board, so that's good news! Keep trouble shooting and eliminating possible symptoms. It's issues like these where there are a number of possible symptoms that might be causing the problem. As a buddy of mine said (who is a very good marine mechanic) "you want to fix the problem, not a symptom"
Good luck. Keep us informed. It's always interesting learning what the problem was.
 
I guess the next thing I'll do is pull the injectors and have NW clean and inspect them. On Saturday I changed the Raycor out and emtied the fuel filter bowl on the engine. The red ring in the engine filter bowl that is supposed to float with any water was right down and the fuel I drained from the Raycor looked fine. It led me to believe it was not a fuel issue but maybe the damage was done from the previous tank or it really doesn't take much.

I also added a litre of Lucas conditioner and injector cleaner with another $60.00 of fuel to mix it in and ran out to the Jetty light and back hoping for a miracle but no such luck. Hoping not to have to drain off 50 plus gallons of fuel.
 
Wow the injectors are easy to pull on that engine. A couple of bolts holding the fuel rail on and and some wiring to unplug. A couple were a little stubborn to wiggle out of the rail but not much more than a 5 minute job. I did see some rust and dropped them off. I will drain the VST and any filters I can find and rig up a temp tank to test it. Looking like bad fuel. The kicker is a carb so I would think it should be fine. Now what the heck do I do with 50 gallons of fuel. I don't cut my lawn that often...
 
Well the good news is the injectors pre-tested awesome at 35cc and I don't have to drain the tank. I had them cleaned anyways to see if we could get rid of the couple of specs of rust.

The bad news is I'm still hunting for the issue. It has to be spark related.... I'll play around some more with it.
 
check the continuity of your spark plug boots. On my older 2 stroke Yamaha I have had corrosion issues between the connection inside the spark plug boot where the wire connects fo the clip that grasps the plug. On mine you can reverse thread the spark plug boot out of the wire and then test continuity from one side of the boot to the other. I ended up changing out all 6 spark plug boots and what I thought was a coil problem went away.
 
I'll give that a try. I already flip flopped the coils at the marina to take that out of the equation and really took some time making sure the wires were on the plugs properly but I'll take another look at them. I think I have some new leads kicking around I never used on a vehicle I sold. If they are a straight boot then I may be able to do a quick test with them.
 
I tested the spark plug leads and they are fine. I've got to pickup the injectors and throw it back together. I'll play around some more with it when I get a chance.
 
All good suggestions above. Have you seen the spark on 2 and 3. Did you pullem and ground them and seen the spark? Does the spark crackle? Sounds stupid I know. Coil pack on 2-3 could be weak producing spark but not enough. It spark or bad fuel. Try the day tank option and premium. Is fuel pumping out the exhaust? Can you see it in the water floating around?
 
I tested the coils as well as the plug leads. But, I've been having a bit of a low voltage issue showing on my Garmin and now I'm thinking that may be where this issue is coming from. Does that sound reasonable? I will charge both batteries up really well and see if she runs good once i get the injectors back. I should have thought of this earlier.
 
I always pull the plug and confirm the spark. If its quiet out it should crackle. When in the shade you should be able to see it. You can compare the spark against 1or 4. When you swapped the coils did you start pulling wire off to see if it switched to 1-4? Or just started it and was the same?
 
I pulled the leads off again one at a time after switching the coils at the marina the first day and 2 and 3 continued to be the weak cylinders. I also pulled the coils and resistance tested both of them with a multimeter today. I've got to get the batteries up on charge and the injectors back in. So I'll probably let it sit for a day or two and I will check spark as well.
 
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Did your oil level change at all. Last year I got diesel in my fuel and the oil level climbed up pretty quick
 
bones said:
What is the outcome? Get it figured out or did it go to a mechanic?
Click to expand...

I got the injectors back and threw it back together. The rain was coming so I got it cleaned up and put away. I put a charger on it and figured I'd get back to it. My insurance ran out on the bike today. I've been trying to get some riding in the past couple of weeks. If the weather cooperates this weekend I'll pull her back out and see how she runs. It's a bit of jockeying around getting in and out with room for stuff around it. Still wondering if she's a low voltage issue. I'll get it figured out, just need to do some more testing. I do have a pack of liquid brined bait if anybody needs some in the Langley area. My season is over. Too many chores left undone.
 
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