LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

[Theoutdoorsman]

I've asked this before but need more opinions from some folks long-in-the-tooth.......

One hole bored (one oversized piston), or all holes bored the same diameter (all pistons the same size)? I've got my doubts on one hole. I'm not trying to be pushy, I just don't want to do this again next season or the following for making a bad decission. And I'm ready to drop this block off in a couple of hours !!!! Can I expect years and years of service from boring only one hole or would I be looking at crank bearing replacement due to uneven compression and/or piston weight? Surely some old timers out there have opinions. Please, I need you guys to speak up. Not trying to start an all out war on this subject, just looking for opinions from folks in-the-know. Thanks a bunch.....................ALAN

 

[Dhadley]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Once the machine shop measures the bores all those questions will be answered. If the motor has very few hours on it and the other holes measure OK, you'll be fine.

If you have a cylinder damaged from a broken ring it usually means the motor was being lugged. That causes a lot of higher than normal combustion temp. On those motors even the undamaged cylinders will be out of spec and need to be bored.

IE - if the cylinder is within spec after it's honed, it's perfectly acceptable to bore less than all cylinders on a 2 stroke. I doubt they will be in spec.

The wear tolerance on a given motor is .004". If when you're done honing it's at .002" over, it will have 1/2 the life of a "fresh" cylinder. .003" over = 25% of the life left.

 

[Dhadley]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

One other thing -- make sure to use a machine shop accoustomed to boring outboards. Do not use an automotive shop.

 

[Theoutdoorsman]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Reason being? I can only assume this is because of the ports within the cylinder walls correct? The machine shop, locally, says they have bored many outboard blocks. Would you suggest I, instead, ship this thing to Mar-Fab? Thanks a bunch............ALAN

 

[Dhadley]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

If they are set up to do outboards, thats great. I'd ask questions first though. Like what do they use for the finished bore size?

 

[Theoutdoorsman]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Thanks Dhadley. I just got off the phone with Kurt at Mar-Fab who has answered a lot of my questions concerning the rebore. I'm thinking it might be in my best interest to allow them to perform the "heart surgery" for me. However, I do think I might find my parts to be a little cheaper elsewhere. Any suggestions?

 

[Dhadley]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Yep. Don't try to find cheaper parts -- that's what you'll get. And they'll end up costing you more in the long run. Use what Kurt suggests and supplies. Trust me, you'll save time and $$.

 

[Theoutdoorsman]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Will do !!!!!

Here, what I think, is everything I'll be needing from Kurt at Mar-Fab. If you feel I have left anything out that should be added, please let me know.


1: 4 new weisco piston kits (as recommended by Kurt)
2: New rod bearings
3: New rod bolts
4: Lower crank shaft bearing (p/n 385503)
5: New powerhead seal kit
6: 2 temperature switches for the heads (p/n 386686) preventative
7: Thermostat Kit
8: Water Pump Kit
9: (2) Carb Kits



Again, if you feel I have left something out, please let me know! And thanks a bunch................ALAN

 

[Scaaty]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Sounds like a real winner to me. You will have just about a brand new motor.

 

[Dhadley]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Wasn't one of the heads all beat up?

 

[Theoutdoorsman]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Yep........ Thanks.

 

[Dhadley]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Give Kurt the casting number on the good head (not the damaged one) so he can match it up as a set.

 

[KYHunter2]

Re: LAST MINUTE QUESTION !!! NEED SOME FEEDBACK FAST !!!

Im a penny pincher at times.

But, as far as the temp. switches .

If you don't know their good. Test them .

If they are good ,I'd just clean them up and reuse.

At $ 50.00 a piece, or so. Its worth the effort.

There's really not much to them.


Im sure your machine shop will tell you.

Just in case , be sure to follow the warm up procedure , with the wiseco pistons.

They need to expand properly , before higher rpm's.

KYHunter
KYHunter