YAMAHA 250 2 stroke questions?

[pine island fred]

Neighbor comes over Yesterday evening, she is crying with tears running down her face. She and her husband have a big PATH FINDER with a 250 2 stroke hung on it, commercial use, thats how they make there living. Engine is on its 3 rd. powerhead and just burned another piston. YAMAHA made good on the powerheads but not this time. Looks like I am going to get involved and dont know what to expect. Few questions!
When a new power head comes from YAMAHA, does it come completely built up or is it a short block? I have a suspicion that a bad injector or two is following the motor around.
When the motor is pulled it will be on an island. This is a big motor and I only weigh 150 lbs. so I figure it would be a easier to go out and pull the powerhead instead of putting the whole thing in a boat and bringing it home. What can I expect as to what the power head weighs?
Have no idea what damage is done, if it turns out to be just a piston and cleaning the cyl wall, do replacement pistons come with rings that are already lapped? I know I will have to take care of the ring end gap.
Please tell me that I will not find a pressed together crankshaft with one piece connecting rods! 3 days ago they had a tank cleaning-fuel polishing service do a job on the fuel system along with replacing all the filters. She is convinced that water caused the burned piston, I dont think so. Your opinion? Might be getting in over my head and am sure I will have a lot more questions.
Motor specs. are Z250TXRB s/n 60VX-1001035. Is fuel injected. Now that the weather is improving, might throw the head in the truck, find RODBOLT, lock him in a garage and not let him out until he fixes it. Will pass him some beer thru the window. regards FRED

 

[aleutianwest]

Re: YAMAHA 250 2 stroke questions?

Neighbor comes over Yesterday evening, she is crying with tears running down her face. She and her husband have a big PATH FINDER with a 250 2 stroke hung on it, commercial use, thats how they make there living. Engine is on its 3 rd. powerhead and just burned another piston. YAMAHA made good on the powerheads but not this time. Looks like I am going to get involved and dont know what to expect. Few questions!
When a new power head comes from YAMAHA, does it come completely built up or is it a short block? I have a suspicion that a bad injector or two is following the motor around.
When the motor is pulled it will be on an island. This is a big motor and I only weigh 150 lbs. so I figure it would be a easier to go out and pull the powerhead instead of putting the whole thing in a boat and bringing it home. What can I expect as to what the power head weighs?
Have no idea what damage is done, if it turns out to be just a piston and cleaning the cyl wall, do replacement pistons come with rings that are already lapped? I know I will have to take care of the ring end gap.
Please tell me that I will not find a pressed together crankshaft with one piece connecting rods! 3 days ago they had a tank cleaning-fuel polishing service do a job on the fuel system along with replacing all the filters. She is convinced that water caused the burned piston, I dont think so. Your opinion? Might be getting in over my head and am sure I will have a lot more questions.
Motor specs. are Z250TXRB s/n 60VX-1001035. Is fuel injected. Now that the weather is improving, might throw the head in the truck, find RODBOLT, lock him in a garage and not let him out until he fixes it. Will pass him some beer thru the window. regards FRED

Should have a got a injector for that hole thats what we do
make sure oil is coming out of oil lines to make sure they were bled
those motors are bad for not being bled right

 

[EAVES]

Re: YAMAHA 250 2 stroke questions?

How many hours gets put on this engine before the hole goes down (since its had many powerheads ) replaced and normally the remans are alot cheaper and have good warranty as well

 

[pine island fred]

Re: YAMAHA 250 2 stroke questions?

Thankyou for your response. Dont know the particulars yet and might not ever know. Boat is used for charter fishing, sight seeing, water taxi. As for hrs. , dont know but they do keep records. She did say that they go thru 10 sets of plugs a year and cases of oil.
My understanding is that the powerheads were replaced by YAMAHA under warranty or entended warranty. Also seems that they still have to pay for the labor on the swapps, so the boat sat for a time until they could bail it out of the shop. Cost her a good bit of change just to have a compression and borascope done the other day. Remanufactured head would be the way to go but is out of the question do to the lack of funds. They are currenty swapping out the motor with a 225 MERC off another boat so they can keep operating.
Word of advice to all that want make a living off their boat. Not that easy, to many people in the business and no one is doing any better than just staying above water. OK for those with deep pockets and just want a hobby job. Stories you hear of people doing great at fish or dive charters, wont tell you that they are very well off from inheritances or family and can afford to rope-a-dope on the water.
Another question, are the cyls. strait or taper bored on these engines? Going to be an interesting project. regards FRED

 

[rodbolt]

Re: YAMAHA 250 2 stroke questions?

what you are dealing with is a 3.3L HPDI 250 HP engine.
its an 03 so there was 3 oil pump updates,one link rod update an ECU update and you now have to figgure out IF they were actually done.
start looking for white paint marks on the rear cover and air box, mostly does the engine look chysler white.
there was also a regulator rectifier recall I think on that engine.
yes the pump bleeding procedure is a bit different than normal.
trust me you wont simply clean up the cyl.
when its bored use a reputable outboard machine shop.
the block assy is put together about like all V outboards for the past 50 years,suzuki's excepted.
there was a crank change that will be different than the original 03 block.
try to ID the part number from the last repair and use that number to order block related parts, this will include the cyl heads as well. any updates that have been done can be found from yamaha by running the engine PID and looking for warrenty history.
that powerhead probably weighs 200 or so pounds dressed.
you may whish to have the injectors tested at Flagship marine.
there are two non-servicable filters in the high presure pump, including those two and the one in each injector there are something like 12 fuel filters/screens on that engine.
if it was improperly bled oil pump that problem will be found in the first 20 min of operation. if it lives the first 20 minutes under a load then the oil system was bled properly.
we blow fuel into that cylinder at 1100 PSI after the piston has closed off both the intake and exhaust ports.
trust me if the cylinders dont seal perfectly it will rapidly selfdestruct.
a lot goes on on a Z 250 motor and all has to be 100 percent or it pops.
thats why I wont sell a commercial guy a Z motor, they simply wont do the maint and it pops rapidly.
I know its a chunk of change but I would reccomend an F250 or an F225 for what they are doing.
with that amount of plugs and oil I would suspect the updates were not done.
the 3.3 motors are hard on oil but the 03-04 Z250's were the hardest. hence the updates.
you may also wish to test the oil line check valve, a bad valve could either lean out the oil or make it very rich on that hole.
use tech bulliten o2007-011 for the correct procedure to ID the oil pump arm as well as the link and sync and bleeding procedures.
if you need the pump and its in the correct PID range call yamaha and cry like crazy.
myself I would use the PID to verify whats been done and if the updates were not done cry to Yamaha.
investigate first then plan a course of action.
the latest pump arm ID is 60v13.
if its not some dealership possibly did not perform the bulliten. the old numbers will be 60v10,60v11 or 60v12. all were warrenty replaced reguadless of warrenty status by 60v13 for Z250 TXRB with a pid range of 60v-10000001 through 60v-1004117. so your buddy should have the 60v13 pump, the link rod and ECU update, the regulator update and white paint spots all over the motor.

 

[pine island fred]

Re: YAMAHA 250 2 stroke questions?

RODBOLT, gave me an awful lot to comprehend. Wont know anything till I go out and get the power head. Afraid this might be the end of there venture. Assume what you are saying, all the EOs. done are recorded in the engine brain and identified with white paint marks ? Done quite often on aircraft.
So, can you share with us on how the replacement powerheads come from YAMAHA ? Full dressed or stripped? Could the problem be following a parts swap? If it gets that far, will definately have the injectors checked or replaced if they can afford it. Sure can understand your not selling certain item to commercial guys. There speed is always WOT on an overloaded boat, something has to give after awhile. Am thinking if I do get this thing back together, putting some kind of throttle restriction on it and not telling them about it. I dispise high manifold pressure.
Change of subject !! Hows the son doing in school.? Met a pretty woman at the tavern, says she knows you. Use to do the granite and marble work on the ego yachts there in WANCHESE, works on SANIBEL now. They still building boats there? Plan to buy you a few beers this summer. thanks FRED

 

[yoyo133]

Re: YAMAHA 250 2 stroke questions?

Tell your friends that if the Bridgestone tires they keep buying always delaminate then it's time to switch to Goodyears or Cooper tires. If they are truly commercial they will be money ahead (after 3 powerheads) to use the Yammy as a mooring, bite the bullet and try another brand. To keep throwing good money after bad is foolish.

 

[rodbolt]

Re: YAMAHA 250 2 stroke questions?

yamaha sends the Z250 powerheads as a block and cylinder head assy. all accesories must be reused but to often they fail to get checked and a repeat failure is inevitable.
this goes for any brand.
piston failure is a symptom not a problem.
most failures are caused by improper setup or maint schedule.
these engines are very durable but like any complex DI motor they require maint and a lot of it or they pop powerheads.
E-TEC,Opti-max and HPDI.
I have commercial guys with over 2000 hours on Z250's and Z300's but they get maintained a bit different than the average joe putting on 50 hours a year.
but once the powerhead is rebuilt or replaced all updates need to be verified and then the entire rig inspected for proper setup and fuel system requirements for both engine and hull side.
had an F115 lunch itself last summer.
when sold the boat had one leaning post seat and a center console.
50 hours later when it came back it had seating for 16 people and at that load was so severly overpropped it detonated a piston.
when everything is done it MUST be propped to run at its upper RPM range WITH the load its carrying THAT day.

 

[pine island fred]

Re: YAMAHA 250 2 stroke questions?

YOYO133, what you are saying makes perfect sense. The original powerhead and the 2 replacements were covered by YAMAHA. Think they just paid for the labor. This time is different, they are on their own. Things are not that good down here, sort of like fillet and release for dinner if you get my drift. I am just getting involved because I have some tools, lots of time, and just enought knowledge to get in trouble but a man has to know his limitations.
RODBOLT, thanks for the heads up on the way the blocks come. Was suspicious that the swapped bolt ons might be the problem. Big boat, big people lots of add ons. Think they should have considered smaller twin power but who am I? PATHFINDER set them back about 45K years ago. Dont want to consider what a new 250 hp. would cost.
Yamaha has to be a good engine as all the tugboats here use them day after day. Am sure they are set up differtly.
This POLACK feels a bit of irish in him tonight, think I will head for the tavern. See if you can start a tab at the BLUE CRAB for me and have a few on me. regards FRED

 

[rodbolt]

Re: YAMAHA 250 2 stroke questions?

mostly Ill wait till ya get here again.
but yes to many times repeat failures are the symptom not the cause.
if ya wish to help your buddy then I wont mind helping you as best I can.
finding a good machine shop is like finding a good divorce attorney, ya sometimes dont know till your done.
yes oversize pistons are avalible for that engine and the block assy is actually put together like and old jonnyrude or chysler.
other than the piston ring design, move along folks nothing new here.