coupler issues + head question

[david_tye]

'89 omc 3.0

My coupler has loosened twice now. .. it took me two engine pulls to realize it was the coupler coming loose. I'm assuming the alignment was off both times. ..So my questions are:
1. Could I use bolts instead of studs to tighten the coupler to the flywheel
2. Would a mercruiser coupler work with my omc outdrive? I have a mercruiser bellhousing as well..
3. I am currently running a head with smaller ports than my original head. .. how much would I benefit from having the head with larger ports rebuilt?

 

[Don S]

Re: coupler issues + head question

Stick with the nuts, but get the proper lock nuts, (NOT nylocks). I doubt you could get the bolt into the coupler just because of the design.

 

[Grub54891]

Re: coupler issues + head question

+ one what Don said,If it came loose the threads on the studs more than likely got beat up a bit,and the nuts are shot. Replace all of it with new,I wouldn't trust studs that were hammered a bit if it were mine. I've seen automotive flywheel's explode,it's not pretty! And very dangerous on a boat to its passengers,and hull.

 

[Bondo]

Re: coupler issues + head question

+ one what Don said,If it came loose the threads on the studs more than likely got beat up a bit,and the nuts are shot. Replace all of it with new,I wouldn't trust studs that were hammered a bit if it were mine. I've seen automotive flywheel's explode,it's not pretty! And very dangerous on a boat to its passengers,and hull.

Ayuh,.... I agree with both of ya,.... New nuts, 'n New studs,.... probably a new coupler,....

How badly is the housin' beat up,..??

Usin' the Merc stuff, I believe will leave ya Short on spline contact area,...

'n if the other head checks out, Sure, throw it on,...

 

[david_tye]

Re: coupler issues + head question

Ayuh,.... I agree with both of ya,.... New nuts, 'n New studs,.... probably a new coupler,....

How badly is the housin' beat up,..??

Usin' the Merc stuff, I believe will leave ya Short on spline contact area,...

'n if the other head checks out, Sure, throw it on,...

The housing nor the coupler itself are beat up at all...I stopped running the motor once it started coming loose.

Thanks for all the replies guys; I'm headed off to try and find some new studs and nuts today.

I'm taking the head up to the machine shop tomorrow. Think I'm gonna get it decked a bit while it's there...

 

[david_tye]

Re: coupler issues + head question

Update...

Got the coupler tightened back on like it's supposed to be and spent several hours properly aligning the motor and fighting with the f*#&#^@)$*#ing outdrive while re-installing it. Got the large port head checked and shaved down .060 and installed.

I took the boat out today...no more banging from the coupler and it didn't loosen back up thankfully. After retarding the timing a bit due to the higher compression, i added about 3-4 mph on my top speed...might get a little more out of it if I run premium.

 

[Bondo]

Re: coupler issues + head question

Update...

Got the coupler tightened back on like it's supposed to be and spent several hours properly aligning the motor and fighting with the f*#&#^@)$*#ing outdrive while re-installing it. Got the large port head checked and shaved down .060 and installed.

I took the boat out today...no more banging from the coupler and it didn't loosen back up thankfully. After retarding the timing a bit due to the higher compression, i added about 3-4 mph on my top speed...might get a little more out of it if I run premium.

Cool,.... I love happy endin's,....