1989 225 Thermostats

Hey all. I recently acquired a boat with twin '89 225 outboards. The prior owner was in the process of re-rigging and it would be kind to say he wasn't an "expert" so I've had to try and undo a lot of his work. I've found that the thermostats in one motor were stuck open and he'd pulled the other motor's out altogether. I've purchased new thermostats and diaphrams that they screw into but had a question. Which direction should the diaphrams face? If you assemble them with the rubber groove ring bulge facing outward (like the parts book seems to show) the cover won't fit against the head until you screw it down and compress everything. If I assemble it with the rubber groove ring bulge facing inward everything fits together with no compression. I know that this is part of some kind of pressur relief system so I want to get ti right. Also, I know one shouldn't run these motors without the t-stats but what about just removing the vernatherm and spring and leaving the plastic bullet housing? Thanks for any/all help/advice.

Re: 1989 225 Thermostats

JonnyT,I have the same motors you have. I run them with the vernatherm and spring out but using the bullet housing as required. As for the proper installation, the bullet should seat in the bulge side of the diapham so that the other side has a small ridge in which the bullet screw will come out. If you don't understand post your e-mail and I will send you pictures. By the way were are you located ?.