[South Paw]

I've hit a crossroad with an outboard deciding whether or not to repair or replace it. I own a 2001 Yamaha 225 hp OX66 which has some serious ignition/electrical problems. The motor has 600 hrs and checks out mechanically and has passed compression checks. Fuel and fuel pump issues have been ruled out. It missfires at higher rpms causing sudden jerks in the forward motion of the boat. While on board you really need to hold on to the t-top or you are gonna fly. We can get the boat to plane but just barely and if we try to accelerate the bottom falls out. Airtime Sports in Hampton has the boat & motor and I have no regrets about that. A Yami certified mechanic working with Yamaha has been working on it and doesn't want to throw any more part$ at it to save my a$$. Yamaha tells him to replace the wiring harness, but we don't have an extra and they aren't cheap. Also the ECU computer could be at fault instead. From what I've been told this motor has a history of being a dog. People who know me and have fished with me know this motor has a long history of overheating due to corrosion buildup in the upper part of the motor. Something I've lived with. Is it time to repower? Should I get another mechanic to look at it? Bill's Marine might have a wiring harness they or we can use to troubleshoot with. I'm pursuing that and I'm seriously looking at financing a new 4 stroke motor. I know Bill's and Troy Marine have got some deals going on.

If anyone can lend me some advice it would be greatly appreciated. Sticking with a motor with a production history of problems seems like a **** shoot, but if an easy fix can be found it might be worth it. On the other hand buying a new motor right now is gonna financially hurt.

Sorry for the drama.

Thanks,

South Paw

 

[trnsmaster]

have same motor 1999 model, sure sounds like hi pressure filter inside vst tank or hi pressure fuel pump going bad or wiring problems to it. first thing at this point is a ride with pressure gauge on fuel system . you always have to be able to see a problem not just feel it to repair it. the guage will show if the fuel pressure drops out to cause the problem. if ok then scope on the plugs while running to see if the fire is cutting out. i blew a piston in mine first batch of ethanol gas. i am in process of closing on a replacement motor. so if you determine you need something external we might be able to deal. another clue to fuel issue is to shut it off after it bogs. turn key to on but dont start. turn off and then restart go to full throttle if it doesnt bog out its probably fuel. turning key on primes the tank. thats how they taught me to diagnose mine. could also have restrictions in fuel pickup in tank, insides of fuel lines flaking making flapper valves in hose, bad primer bulb bad hose from bulb to engine.have they run it off temporary fuel can ? need to know whats been done so far . eme [email protected]

 

[South Paw]

Thanks trnsmater. We have hooked up an external tank directly. So that's not it. I have had fuel pumps go bad on this motor and others and usually that results in much slower jerks. These are very quick and pronounced which means electrical problems to me. Air Time Sports has assured me that they have checked fuel pressures and supply, the motor is getting what it needs. The yamaha mechanic is a personal friend of mine and no rookie. He's doing the work for almost no cost to me. The thing is this motor, the model has a bad history. If I'm wrong please chime in someone! I'm at a point where parts are going to be expensive. ECU costs $1400. Wiring harness $700. Do I really want to seriously chase a problem down that has a master yamaha mechanic stumped right now?

Good Fishin

 

[27 sailfish]

If you are on a trailer and willing to bring the boat up to Baltimore, Md - we have a great Yamaha guy.If he can not fix it- no one IMHO can.He does a lot of warranty work and often gets the hard to fix problems that other mechanics can not repair.

Figure a new motor will run at least $12,000.00 PLUS rigging - OUCH.Even if you put $1,000 - $2,000 in yours, you will still be ahead.600 hours is nothing plus the compression is good.

Give Ed Miller a call 410 375-1638.You might be able to drive it up, stay one night- then take her back home.I'd guess 5 hour drive from Va. beach.

 

[South Paw]

New motor is more like 14K. Ed's Marine I was told has the best prices. I would buy from them and have Air Time install. I already mulled this over with Air Time. If I put 1 or 2 K into this motor and a month later I look under the cowling and I see a piston rod punched through the block I'm gonna die. And did I mention the corrosion the previous owner built up in the motor causing overheating often. Anybody have an opinion/info about this particular motor? I was told it was good for about 1900 hrs.

Thanks 27 Sailfish. I will call up there Mon. morning. Can't hurt.

 

[c-note]

Is Chris your mechanic here in VB? If not let me know I will give you his number.

 

[South Paw]

C-note,

Thou is my mechanic at Airtime Watersports in Hampton. Who is Chris?


Mike

 

[chromeoverbrass]

To get rid of any engine, gas, diesel, inboard or outboard with only 600 hours would be obsurd unless you have self inflicted damage that you are not talking about. Electrical, did the boat have some kind of water damage? Overheating? are you keeping up with flushing and changing water pump components and thermostats regularly? Before I would consider buying a new engine package, I would get two more opinions. Just cause they are certified doesn't mean a whole lot.....

 

[tommy1]

Post your problem on MarineEngine.com and i bet you will get some great info from this site. Hope this helps, we have just like it, VST high pressure pump filter was the cause of our problem...and the temp alarm goes off on our in the summer if you idle to long...on that site you need to look for an answer from Just n time

 

[trnsmaster]

who ever told you that a 225 ox66 was a problematic motor is your main problem.. god help you if thats who is working on your motor!! its one of the best outboards ever produced. know some with 5000 hrs. we had 3000hrs on ours when we got load of low octane fuel and melted one. tstats poppetvalves water pump 3 vacuum fuel pumps every other year is routine maint for them.as for the jerks ours was like someone just turned the key off your about to go thru the windshield and it picks back up and throws you back in seat if you were standing. you would be surprised by what looks like a free flowing vst screen but its actually clogged. yama bought me a couple hi pressure fuel pumps cuzz i would show the grit on the screen after the fuel passed thru a racoer and a yama10 micron plus the engine fuel filter. some inexperienced techs called it ethanol deposits on the screen. one sure test is poke a bunch of holes in the vst filter and go fur a run.

 

[trnsmaster]

most ecu/computer problems either show up after box gets warmed up, or are bad ground connections. why replace a wire harnesss when all the leads could be scoped out ? are you dealing with parts changers or technician???

 

[Bust it Big]

O2 Senser. Been there done that.

 

[5th Tuition]

Year 2000 yamaha ox66 200 h.p. had issues. Trolled for a couple hours then wouldn't pick back up and get on plane. It would shut down like it was starved for fuel. On about the third try it would finally pick up and run. Also while running, it would surge; then pause. New O2 sensor and vst filter solved my problems. I hope you get that lucky!!!!! 5th (Marty)

 

[trnsmaster]

ecu can be rebuilt by a company in washington state much like cars computer.

 

[South Paw]

Good info so far. Thanks all. Trnsmater your description of the power jerks is right on the money. She'll quit, sending you forward and then all of a sudden a burst of power which throws you backwards. You can't stand up without holding on to something tight. I'm going to look into the VST filter. O2 also Great ideas. Thanks. Tomorrow I'm headed to Bill's Marine they claim to have over 30 yrs experience working on OBs. I'm just going to talk to them. Next I'll go to Troy Marine another Yami mechanic. 600 hrs. is nothing for a Yamaha. I can't say bad things about my mechanic friend who worked on it. He did alot of work for free and I know he meant well. Maybe it wasn't necessarily the best with the most experience. That's why I'm 2nd quessing. I'm still focused on the question "Is this 2001 Yamaha 225 HP OX66 a good motor?". Trnsmater I heard you. Thanks. I'll ask more mechanics. Anyone else have experience with this motor?

I have taken care of this motor, bought with about 300 hrs. No self inflicted damage. Kept up with changing thermostats, impeller, lower unit oil, spark plugs religiously.Previous owner didn't flush the motor that's why I've got blockage/corrosion issue (my mech's theory) in the motor and she overheats when I go from idle to low RPM often. Or if you idle too long. I take her out of gear and rev it a bit and that takes care of the problem. Hmmm almost sounds like a VST filter problem mentioned earlier.

Many thanks,

Mike

 

[trnsmaster]

poppet valves for overheating . they are kinda like tstats for water flow. thats probably your restriction. especially how you descibe the low speed part, the weird thing about the vst filter problems is ours didnt show up until i had just picked boat up from spring service. ist trip out on way home it acted up thought tech screwed something up. it took them 2 weeks and 150 gal of fuel to find problem. vst filter was last on list to check since it was brand new !!! o2 sensor wont give you jerking you just loose power or fuel economy etc. it was our 2nd or 3rd year when this problem occurred. yama has since made a bigger filter to flow more gas. 3 or 4 yrs ago people started experience this problem more preventlently due to fuel grades.mixes. when our motor melted a piston it was partly our faults as we were trying to beat storm in and it was running rough but we kept going. go to hull truth.com do a search for your problem check shipyard island marines section there also. yama didnt have """bad motors "" until the race for monster motors that pass epa/ 250 hpdi was first to have alot of issues.ox66 are great motors and 200hpdi is another classicbtw we flushed ours religiusly first year then never again unless it was on muffs for service no corrosion when we pulled head ten yrs later , now i have seen motors with electrolisis corrosion due to internal zincs not changed .

 

[26Albe]

I had similar issues with my 97 250 OX66. Motor would overheat at low rpms after trolling for a while, alarm would sound. Try getting up on plane and nothing. Shut the motor off and restart, wouldnt overheat for another hour or so but still no getting on plane. Changed waterpump and a few seals that were bad and it runs like a champion now. If you are local to Va Beach I would highly recommend Virginia beach Contender for your service needs, they come to you (at no charge) or you can take the boat to them for service. Not to mention their labor rates are cheaper than any other service dept in the area. Call David and he will get you fixed up.

 

[tommy1]

You can change the VST filter your self its not a bad job, i just loosen all the screws on top then remove the 3 10mm bolts that hold the tank to the block pull the bottom off and the filter has to rotate out then you pull it down and off.......i tried to clean ours would work for a while then it would get stopped you again replace it that works better and when you store the boat drain the VST tank, brass screw on the side of the tank. Hope this gets you going

 

[South Paw]

I talked to Bill's Marine and to Troy at Troy Marine in person. Troy is a real knowledgeable person on Yamahas I spent a good hour with him. Time well spent. Airtime Watersports sent me to him for advise and info on new motors. Bottom line and the biggest piece in this puzzle: This nonrelated overheating issue, serious corrosion in my motor is making it a time bomb. A problem that I feel makes the crazy jerking problem right now not worth pursuing or getting fixed. The previous owner did not flush his motor. That and a number of other things. We did poppet valves, we did stats we did impeller. The guys at Airtime, who I see and talk to everyday and are my friends and their families I know were politely trying to tell me all along and this is in Troy's words " You got a piece of SH*T" for a motor." What I learned was that the OX66's typically last around 1300 hrs. They are good motors, just not mine. That's if you are a typical owner who is isn't religious about changing ALL filters every year. If you change everything including the VST, use Yamaha's micron filter, Yamalube and run Ringfree you got a shot at getting the motor past 2000 hrs. Troy has only seen one go the distance. The VDI series is a little better and lasts longer. This ethanol is bad news, we all know that. Gas is so bad that there are pieces of corn in it. I kid you not. I guess I'll find out how well a 4 stroke drinks that because that's what I'm buying.

Thanks for all the help and I hope something was learned here.

Good Fishin

 

[Scotsman]

Dont know whether this is of any use to you, but on my previous engine (93 150 OceanPro) I has a similar missfiring issue at higher speeds/RPMS. Exactly the same symptoms as you describe. After working through the list of possible causes finally fixed by replacing the powerpack. Apparently a common problem with this engine.

Its a good excuse to get a new 4st engine


Hamish