Engine Troubles

[frayedspool117]

Hey whats going on, My name is Andrew and I am new to this forum. I found you guys through reading an article In Offshore, A northeast region boating magazine. I just wanted to say I am glad I have found a forum with other loyal Seacraft Owners. I love my hull and its design. This is my first boat, and sure when I get my captains license, I will be purchasing a 23 foot Seacraft. I have had the boat boat in 6-7 foot seas and was damn proud of how she handled. I love the hull very much, unfortunately my 2000 Yamaha 130hp is turning into be a love hate relationship.

I was out fishing the MiddleGrounds off of Marthas Vineyard when I went to make another drift, and punched the throttle. The boat took off and then all of a sudden bogged down and sputtered to its death. The engine wouldnt start again. I pulled the cover off changed the spark plugs. (all fouled) and it started but ran shitty back to the dock.

I bought the boat about a year ago and this was my 2nd time using it. Turned out it had bad gas in it. I drained the tank, changed all fuel filters, all fuel lines, and cleaned out the carbeurators.

This was not the problem. Still dint run right. I ran a compression test on all of the cylinders cold, and I was pushing 125psi out of all of the cylinders.

One cylinder is not firing and gets weak spark, plus the boat does not rev up fast. It bogs itself out. This is the kicker also. When the choke is turned off, it runs like crap, but when I have the boat half choked, it runs like a dream on the 3 cylinders.

So my Question to you guys is, what the hell is going on. I cannot figure it out for the life of me. If all the coils are ok, why isnt one cylinder isnt firing, and what could be causing my bad fuel/oil/air mixture. I am baffled.

Also I want to do the repairs myself. For 2 reasons, I am piss poor. I took a huge chance buying this boat, because my life dream is to be a charter captain and commercial fisherman.

The second reason is that I own the boat and I should learn as much about the engine as possible.

Any ideas would be appreciated.

Thanks

[gw204]

Frayedspool, welcome aboard! [img]/images/graemlins/smile.gif[/img]

Do you have a water separating fuel filter between the tank and the primer bulb or just the small filter on the engine? The fact that you have to choke the motor to keep it running indicates to me that the carbs are still fouled.

Just a few more questions:

How fresh is the gasoline in it?
Did you add stabilizer to the new gas after you first drained the tank?
Did you perform a complete rebuild of the carbs or did you just do a quick spray cleaning? If not, I suggest you do that. The process is pretty inexpensive and easy. I did a complete overhaul on all three carbs of my old 150 Merc. for under $100. That included new gaskets, new needles and seats and new jets.

Take it one step at a time. I would concentrate on getting the fuel system right before you look at the misfire. The one cylinder in question could be running so rich that it just kills itself.

Good luck. [img]/images/graemlins/cool.gif[/img]

[PipeDreamsMarine]

Sounds like you have a bad coil...You said that one plug is firing weak?. .that's a bad coil.. Firing intermitantly is the trigger under the fly wheel is bad. Replace the coil first. If you still have a weak or intermitant spark change out the trigger(OMC term for the device that fires the coils) doesn't sound like fuel to me..at least at this point.

[pogden]

Did you buy a service manual yet? If not I suggest you get one, you can find them on ebay pretty reasonable. try to get the factory manual although Sealoc and Clymer are alright (rebuilt four motorcycles and a VW using a Clymer).

[frayedspool117]

When I redid the fuel system I put 10 fresh gallons of 89 octane fuel in it in hopes it would burn a little hotter. I put 2 containers of stabilizer in the tank. I did not completely rebuild the carbs, I just took them off cleaned the jets, made sure the floats were at the same measurement and cleaned thm with compressed air carb cleaner and a toothbrush.

I also did change the water seperating filter. I am pretty much off the water for the rest of this season. So I think I am going to invest in a new gas tank.

Does anybody know where I can find one?

[frayedspool117]

I swapped 2 of the coil wires and that same cylinder wasnt firing, so that rules out the coil. I dont believe my boat has a trigger. The coil wires go to the power pack...

[ocuyler]

frayedspool117,

Welcome to the Classic SeaCraft forum. I, for one, admire your dream and you should pursue it as best you can. There is no shortage of us here that wish they followed their dreams....

I think Don and Brian may both be right. I've had these issues on snowmobiles that sit for months with untreated fuel only to find out at the start of the season that the carbs need rebuilding (or at least a good cleaning) to run right. The half choke comment is a dead giveaway.

I would defer to Don on the coil thing, because he's always right (although, his wife would disagree).

Personally, I like to see a Yamaha dealer do this kind of work as they have the experience, books, parts and tools, not to mention, it's what they do. But poor is poor. Been there...

Best of luck.

[cSickNick]

Did you open up the power pack cover? Corroded or bad connection to that coil? That's my guess.

One thing to keep in mind, these motors Yamaha 115 or 130 are simple and in my opinion very reliable. Most issues are fuel related.

You may also have a fuel problem. What fuel line/primer bulb do you have? If it is a Tempo .. throw it away!! They will suck in air, giving erratic running .... get a Yamaha one.

One of the best ways to "rule-out" fuel issues, get a new portable tank, new Yamaha line and connect to motor. How does she run? Another problem area over time is the fuel connector on the motor, rule-out by bypassing.

Good luck ... [img]/images/graemlins/smile.gif[/img] - Nick

[PipeDreamsMarine]

Otto I hear your wife calling you... You said you changed the coil wires.. Did you change the coil?.. Your motor has a trigger, because what do you think makes the power pack work in time with the pistons, you don't have a cam shaft and a distributor...Weak spark is your problem...Forget about the fuel till you get good spark on all 4 cycl....