nut size OX66

[flatstick]

Looking to change the flywheel on my 200 hp 1998 OX66.

What size socket is the nut that holds the flywheel on ?

Did some research and 36 mm came up a couple of times for larger motors.

Can anybody confirm that ?

Thanks

[CJ1]

Yes, it is 36mm. Or if your like me and the 36 is a impact socket, you just use a 1-7/16 12 point. Worked fine. The biggest problem was holding the flywheel to torque it. Cj

[flatstick]

Yes, it is 36mm. Or if your like me and the 36 is a impact socket, you just use a 1-7/16 12 point. Worked fine. The biggest problem was holding the flywheel to torque it. Cj

Thanks for the info .

Was looking to hold the flywheel with tool below, that I saw on Amazon, unless somebody has a better idea .

https://www.amazon.com/dp/B000FN7JE2...535999783&sr=1

I will be using a regular socket set with 1/2 breaker bar .

Hard part seems to be getting the flywheel off .


Going to use some type of harmonic balance puller , trying to avoid using a hammer like some people have been.

[CJ1]

Used a balancer puller like you stated. Popped off with just a 3/4" end wrench. Cj

[flatstick]

Used a balancer puller like you stated. Popped off with just a 3/4" end wrench. Cj

Wow did not think it would come off that easy .

how east what is to torque down and 200ft lbs correct ?

[CJ1]

Wow did not think it would come off that easy .

how east what is to torque down and 200ft lbs correct ?

I believe it was in the 140lb range, but I will check when I get home. I held the puller with a large crescent wrench and maybe put 60-70 ft lbs on the 3/4" end wrench and it popped off. I always try that before the impact comes out! CJ

[CJ1]

137 ft lbs. I pulled it down to around 80 to be sure it was seated and straight then hit it with my impact. I have used this on literally 100's of lug nuts and it always torques to 140 ft lbs on setting #2. So I am there. Do NOT try to hold the flywheel with the starter, you more than likely will damage something. And it is 137 ft lbs not 200. CJ

[flatstick]

137 ft lbs. I pulled it down to around 80 to be sure it was seated and straight then hit it with my impact. I have used this on literally 100's of lug nuts and it always torques to 140 ft lbs on setting #2. So I am there. Do NOT try to hold the flywheel with the starter, you more than likely will damage something. And it is 137 ft lbs not 200. CJ

Thanks for the info on everything . can't wait to get the HTEC lighter flywheel on there . hoping for a great holeshot.

[CJ1]

Thanks for the info on everything . can't wait to get the HTEC lighter flywheel on there . hoping for a great holeshot.

No problem, been chasing a idle rpm miss on mine. been through just about everything. Getting a set of injectors back from brucato we will see if that cures it. Almost has to, it is the only thing left. Have a 250 ECU on it now, we will see how it runs with that. Need anything else just ask. CJ

[ClarkBird]

Did you pic up that ECU, CJ?

[CJ1]

Did you pic up that ECU, CJ?

Yes, along with everything else from the engine except the block and crank. Cj

[ClarkBird]

That was a good find, they don't come up very often.

[flatstick]

No problem, been chasing a idle rpm miss on mine. been through just about everything. Getting a set of injectors back from brucato we will see if that cures it. Almost has to, it is the only thing left. Have a 250 ECU on it now, we will see how it runs with that. Need anything else just ask. CJ

Good luck on getting that rpm miss fixed. hope the injector cleaning takes care of it for you.

Just had mine done last year and should have done it sooner .

[CJ1]

Good luck on getting that rpm miss fixed. hope the injector cleaning takes care of it for you.

Just had mine done last year and should have done it sooner .

It appears to be the injectors, running great now. cj

[flatstick]

It appears to be the injectors, running great now. cj

Glad to hear that the injector cleaning has helped you out. well worth the money when I had it done.

[flatstick]

got around to tackling removing the original flywheel the other day .

The nut came loose without any issues.

Used the harmonic balancer puller and got it pretty tight before the flywheel broke loose with what sounded like a gun shot.

Used a fan clutch puller that I have to hold the flywheel while tightening the nut back down on the lightweight pulley.

Just going to borrow my friends torque wrench to make sure I get the 140 ftlbs before calling this small project complete.

Can not wait to get it out on the water , hoping this week .

Thanks again to all of those who offered up advice.

[CJ1]

Glad to hear it worked for you. Cj

[allstock]

got around to tackling removing the original flywheel the other day .

The nut came loose without any issues.

Used the harmonic balancer puller and got it pretty tight before the flywheel broke loose with what sounded like a gun shot.

Used a fan clutch puller that I have to hold the flywheel while tightening the nut back down on the lightweight pulley.

Just going to borrow my friends torque wrench to make sure I get the 140 ftlbs before calling this small project complete.

Can not wait to get it out on the water , hoping this week .

Thanks again to all of those who offered up advice.

Please post up the performance results, I can't wrap my head around a lightweight flywheel improving performance. I get the benefits of less rotating mass being easier on the top bearing with reduced gyroscopic forces etc, and for high rpm use you don't want a bomb rotating at 8k+ rpm, but...

[ClarkBird]

Quicker acceleration, won’t add power.

[allstock]

Quicker acceleration, won’t add power.

Measurably faster or "I think it feels faster because I spent money" faster? Not trying to be difficult but I like to quantify changes before spending $$$.