My buddies boat needs a new powerhead - he has 1,250 hours on F300 - Does anyone have a rough idea on how much this would cost? I told him to take it to West Coast, but he would have to travel from Ventura.
TIA
TIA
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New Powerhead for F300
- Thread starter Bend Session
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6k thats just the head.
The motor ingested water - I think he was having a problem intially with "making oil". Then went chasing tuna back in November, and put on a bunch of hours on the engine. When he pulled the oil dip stick, a bunch of oil/water came shooting out. He had to get towed back to the ramp. Now he has let the water sit, and hasnt done anything.
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The problems with making oil and getting water in the oil are two different animals. one is fuel getting into the oil through piston wash and the other is related to a gasket or possibly cracked head/ block.
Bad head gasket with minor rebuild and clean up and flush could be 3-5k.
Bad heads with the same as above service figure 5-7k
Whole new power head w/ core with R&R figure 11-14k
Whole new power head w/o core with R&R figure 12-16K
One of the real issues is going to be finding a good powerhead ready to go. Inventory is still low around the country so you might have to settle with some off brand shop and or high shipping costs for a powerhead ready to go.
If i were him id flush that motor as much as possible with diesel and oil and hope its not turning into a block of rust inside.
Bad head gasket with minor rebuild and clean up and flush could be 3-5k.
Bad heads with the same as above service figure 5-7k
Whole new power head w/ core with R&R figure 11-14k
Whole new power head w/o core with R&R figure 12-16K
One of the real issues is going to be finding a good powerhead ready to go. Inventory is still low around the country so you might have to settle with some off brand shop and or high shipping costs for a powerhead ready to go.
If i were him id flush that motor as much as possible with diesel and oil and hope its not turning into a block of rust inside.
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Could have been the thermostat. If they get stuck open, the engine will not heat up enough and water vapor will not burn off and be introduced to the crank case, adding to the oil. Letting the water sit in there after finding it is just a straight knuckleheaded maneuver.
Jesus Christ.
Sounds like your buddy should be more thoughtful about maintenance. Must have deep pockets. Good luck!
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Agree with this. It's what he should have done immediately upon finding water in the oil...
Because the water inside was fresh, and not salt, there shouldn't be much/any corrosion. He should be okay if I am correct.
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The guy is a home loan/refinance/loan officer, he has been struggling for cash, guess he plans to spend some tax money on the repair. Probably gonna cost more cuz he didnt remove the seawater from the motor.
He told me the motor would only make 4500 rpms, and then would surge from 300 to 4100 rpms, no alarm or overheating, but when he got back he noticed oil leaking outside of lower unit and oil under cowling and all over motor checked dipstick and found water in oil
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No, the water would be adding itself straight through the pistons.
When the motor takes air into the combustion chamber, that air includes water vapor. If the motor does not heat up to its normal operating temperature, that water vapor does not get burned off and adds itself to the oil. This goes on and on, and you get enough water in the oil to cause increase in pressure and eventually it pops out the dipstick like your buddy has found out the hard way.
You gotta change out your thermostats. Easy to do and cheap as well.
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Tell him to pickle the motor with diesel for a week and then flush it with clean motor oil a couple times. He might be okay
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Boy the description sounds bad. Loss of power and then a huge surge in the idle ending in oil bleeding out... If I were a betting man, which I kind of am Id put 50 bux on a cracked head.
Unfortunately Yamaha, even with all their good rep and love here has had their share of problems trying to be light and efficient.
Hpdi's had bad pistons that lost their locator pins and fuel filters that needed constant changing.
Early 4 strokes had horrible corrosion problems.
F250/f300s up to around 18-19 have issues with the heads cracking.
F350s liked to snap their cranks and throw the flywheels off balance.
F425s? They seem to be holding up good, but most of these owners are truly open check book maintained by professionals.
All that said, I'm still repowering my skipjack with an 05 hpdi 300
Unfortunately Yamaha, even with all their good rep and love here has had their share of problems trying to be light and efficient.
Hpdi's had bad pistons that lost their locator pins and fuel filters that needed constant changing.
Early 4 strokes had horrible corrosion problems.
F250/f300s up to around 18-19 have issues with the heads cracking.
F350s liked to snap their cranks and throw the flywheels off balance.
F425s? They seem to be holding up good, but most of these owners are truly open check book maintained by professionals.
All that said, I'm still repowering my skipjack with an 05 hpdi 300
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Do yourself a favor and google "300 HPDI problems"All that said, I'm still repowering my skipjack with an 05 hpdi 300
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done and done, i have over 900 hours on mine already. pulled it off to repower my speed boat with a 300 mercury v8. the hpdi is a good motor, but the mercury is overall more stable, faster and more comfortable above 80mph.
Most of the problems with the HPDI are attributed to 3 areas that are easily fixed:
#1) the pistons from yamaha are garbage. i don't care how good they are in other engines, they are junk in the hpdi. WSM pistons with molly coated skirts fix 99.9% of the power head issues. Most of these die a horrible death from detonation. this usualy fractures the pistion causing scoring or it knocks the locator pin loose and ring hangs up on one of the ports. the WSM pistons do not have this problem.
#2) shutting down 2 of the cylinders causes uneven heat cycles. so when your sitting there idling for an hour those 2 pistons cool down and rattle around. then some one sees a school or decides to head for home and jams it home. well, esentially they are going full throttle/load with 2 cold pistons (this is also why most failures are on these two cylinders). you can either A: idle in gear for at least 3-5 minutes to warm up the engine or, B: put in an over-ride switch on the neutral switch. the engine needs to start in neutral for full power but after that you flip the switch and it idles on all 6 all day.
#3) those stupid mystery filters get clogged up and a lot of people ran them lean until they popped. All you need to do is put in a canister 2 micron filter right before the engine and check them every other year.
I personally like the HPDI for a fishing motor, a full rebuild is kit is only 1200 bux and you don't even have to pull the powerhead as long as you do it before it pops. A whole new powerhead with 1 year waranty and wsm pistons is only 4k. and the last reason i really like them, is because people run the f*ck away from them leaving lots of cheap parts that are easy to find.
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