Honda F12x Big Turbo Lag

[NOIDEA]

Hi Guys

I'm new to the forum. Thank you everyone for all your help. The ski is a 2005 model with a 107 hours. The problem is that it takes forever for the turbo to spool. Only starts to make boost at around 5200 rpm. It is very slow out the blocks but top speed is fine around 61/62 mph. there is also no fault codes on the ecu. So I went online and found a brilliant website called GREENHULK! So I see that most people having problems with the turbo is the waste gate actuator being stuck. So I checked and mine is stuck in the closed position. So why dint I get an over boost warning and why does it take so long for the turbo to spool? Maybe the waste gate itself is not seating properly?

Thank you in advance.

[supermac]

Hi Guys

I'm new to the forum. Thank you everyone for all your help. The ski is a 2005 model with a 107 hours. The problem is that it takes forever for the turbo to spool. Only starts to make boost at around 5200 rpm. It is very slow out the blocks but top speed is fine around 61/62 mph. there is also no fault codes on the ecu. So I went online and found a brilliant website called GREENHULK! So I see that most people having problems with the turbo is the waste gate actuator being stuck. So I checked and mine is stuck in the closed position. So why dint I get an over boost warning and why does it take so long for the turbo to spool? Maybe the waste gate itself is not seating properly?

Thank you in advance.

What is your MAX rpm.

FYI, the engine wont turn 5200 without a few psi of boost. It could be operating normally for a stock ski.

[NOIDEA]

Max rpm is about 6000. There is definitely something wrong with it. My dad’s friend has exactly the same ski and his pulls much harder from a stand still then mine. Top speed is more a less the same but from a standstill he wipes the floor with me. His ski is also bone stock. My question is why didn’t I get a overboost warning if the wastegate is stuck close? All the exhaust gasses are going through the turbo’s turbine so it is supposed to make too much boost @ 6000 rpm with a stuck wastegate? If I close the throttle and open it up again it takes about 10 seconds before there is power again. It is like the turbo is taking about 10 seconds to spool.

[NOIDEA]

Thank you Supermac . I just want to point out by stuck I really mean stuck. The actuator is realy rusted badly. I managed to loosen it up with some WD40 and pliers. I will replace the spark plugs and take it for a test run on Monday morning. The only thing I can think of is that maybe not all the fuel is getting burned and that is why it is not making too much boost.

[Boost-A-Holic]

i dont know too much about honda skis but i would check your pump assembly. problems with that can lead to lower RPMS and drop in performance. Make sure you didnt suck anything up and damage the impeller. The wastegate should be fairly difficult to open up because it takes a certain amount of boost pressure before it opens up. Even with a 5lbs spring on my wastegate it takes some man power to get it to open up with ur hands.

also check for boost leaks you might be loosing some peak boost pressure up top. Do you have a boost gauge on your boat so u can see if ur down on psi? Check all ur intake lines, couplers, IC, etc... Even check for an exhaust leak near the turbo u never know where u could be loosing boost.


i dont know how long those turbos last on those boats but maybe ur due for a rebuild??? 107 hours on the same turbo?

[supermac]

i dont know too much about honda skis but i would check your pump assembly. problems with that can lead to lower RPMS and drop in performance. Make sure you didnt suck anything up and damage the impeller. The wastegate should be fairly difficult to open up because it takes a certain amount of boost pressure before it opens up. Even with a 5lbs spring on my wastegate it takes some man power to get it to open up with ur hands.

also check for boost leaks you might be loosing some peak boost pressure up top. Do you have a boost gauge on your boat so u can see if ur down on psi? Check all ur intake lines, couplers, IC, etc... Even check for an exhaust leak near the turbo u never know where u could be loosing boost.


i dont know how long those turbos last on those boats but maybe ur due for a rebuild??? 107 hours on the same turbo?

The turbos will last forever unless they are abused. (corrosion or FOD)

Check for damage and a boost leak. 6000 is normal for a stock 3 seater in warm weather.

[NOIDEA]

Thanks for all the help guys. Yes 107 hours on the same turbo. No unfortunately I don’t have a boost gauge. I’ll check for a boost leak on the compression side and check for any cracks and leaks on the exhaust side. LOL yes it does take quite a bit of man power to open the wastegate. I will also do a compression test on the cylinders. Supermac can you tell me what the compression must be for a 12x turbo engine?

Thanks again for all the help.

[JoeyDFZS]

170 something I believe......

[NOIDEA]

Thanks Rick

[JoeyDFZS]

when you do the compression test you must remove all plugs......remove gray sub air box cover........unhook injectors and crank and hold throttle wide open........ I believe thats the most accurate way to do it, otherwise I believe you get low readings

[supermac]

when you do the compression test you must remove all plugs......remove gray sub air box cover........unhook injectors and crank and hold throttle wide open........ I believe thats the most accurate way to do it, otherwise I believe you get low readings

Just make sure all 4 agree in PSI, dont worry about a number.

BUT, I wouldnt even bother with that test.

If you are turning 6000 your boost is most likely fine. You cant get to 6000 otherwise. You could have a prop that is too steep, like an 18/30. My bet is on that.

[NOIDEA]

[NOIDEA]

Thanks Rick I’ll do that. Here are some pictures I took from the spark plugs. They seem to be very black. Checked the exhaust for cracks and leaks, could not find anything wrong with it. I removed the grey air box cover and plugged the pipe that comes from the IC. Then I removed the boost pipe from the turbo and used the air compressor to get the pressure up to 17 psi. There were no leaks on the boost side. Thanks Mac I’ll check the prop.

[Boost-A-Holic]

those plugs are dirty as hell change those things out for sure!

[NOIDEA]

I did change them. Here is a picture of the new ones.