03 Merc 2.5 questions

[wired247]

Look at the back of my skeg...

[Slimm]

Look at the back of my skeg...

Thanks Wired, is that something that is added to the skeg or is the skeg notched and then another piece welded in? I assume that is there to combat steering torque, is that correct?

Thanks
Slimm

[wired247]

Theres a number of ways to do it. Bobs Machine and others sell a rivet on skeg wedge to counteract the steering torque . There are also weld on versions. Mine was built out of relatively low temp MIG wire overlayed about 3/8" thick over the parent skeg material and filed and sanded to shape when I was doing the nose cone addition. Some people build them out of epoxy or some of the stronger fillers.

[Jay Smith]

Cutting O ring heads is no issue we do it all the time, for 2.5 and 3 liter with stock OEM O ring grooves put back, I use TDR reeds valves in ALL my rebuilds, unless you have a very long tuner your stocker will be ok for the limited rpms that motor will turn with its ignition..

Jay

[Slimm]

Cutting O ring heads is no issue we do it all the time, for 2.5 and 3 liter with stock OEM O ring grooves put back, I use TDR reeds valves in ALL my rebuilds, unless you have a very long tuner your stocker will be ok for the limited rpms that motor will turn with its ignition..
Jay

Thank you for the input Jay. I assume you would cut the heads for a desired cc, and would like to know what the safest chamber volume would be for pump gas. Also do the TDR reeds have options for better low end, or mid/top end or do they have a single reed set for my engine? Do you have rod bolts for this engine?

Thanks,
Slimm

[Jay Smith]

IMO the TDR reeds are THE best available for any outboard application, all out race and recreational use.. Cutting heads we target for top pump gas numbers of 145 lbs cranking compression at sea level...

Jay

[Slimm]

Ok peeps, lets talk rod bolts. Who has 'em and if there is more than one brand to choose from what are my choices?

[TEXAS20225]

ROD bolts part number @ pro marine RB8000P over the counter is around 4.00 each. the fishing motors dont have rev limiters per say its the electrics that hold them back it does not have a specific BOX that's called limiter the CDM motors wind a little less then the switch box motors around 5800 and of course the set up and boat weight has a lot to do with how tight you can wind it. i have removed the oring heads off these motors and ran gasket heads the squish band on your motor is .044 thousandths you can add a stock head gasket and gasket head the compession will be very close to the same ive done it many times ive also scrapped the cdm's and changed it to switch box style electrics with right set up it can twist 6200 on my EFI's, carbs maybe a lil more Good luck oh yeah i would NOT do what all i did unless you have 2500 square foot of parts laying around it could get pricey
s

[Slimm]

ROD bolts part number @ pro marine RB8000P over the counter is around 4.00 each. the fishing motors dont have rev limiters per say its the electrics that hold them back it does not have a specific BOX that's called limiter the CDM motors wind a little less then the switch box motors around 5800 and of course the set up and boat weight has a lot to do with how tight you can wind it. i have removed the oring heads off these motors and ran gasket heads the squish band on your motor is .044 thousandths you can add a stock head gasket and gasket head the compession will be very close to the same ive done it many times ive also scrapped the cdm's and changed it to switch box style electrics with right set up it can twist 6200 on my EFI's, carbs maybe a lil more Good luck oh yeah i would NOT do what all i did unless you have 2500 square foot of parts laying around it could get pricey
s

Thanks Texas, I appreciate the info and the tips. Is there any real difference in performance or longevity between the oring type heads I have and the older gasket type?

[TEXAS20225]

the biggest plus is getting them cut is a LOT cheaper and there are quite few already floating around that are 34/35 cc cut you can buy gasket heads cut cheaper then you can have the oring ones cut as far as better Naw a cumbustion chamber is a combustion chamber the cylinder does not know what kind of gasket it has klast i checked it was 300+ to get some cut

[wired247]

Isnt the deck height higher on the O ring head motors so he's need a smaller chamber or to cut the deck to get the compression he needs.?

[TEXAS20225]

044 thousands squish band as stated plus a very thin oring . here is a been there done that nugget for you guys when you take a oring head and cut the groove out of it that seats the oring the head with a gasket will yield a 34 cc head

next one cost you a entry fee

[Slimm]

044 thousands squish band as stated plus a very thin oring . here is a been there done that nugget for you guys when you take a oring head and cut the groove out of it that seats the oring the head with a gasket will yield a 34 cc head

next one cost you a entry fee

Ok, so from what I just understood you say is that if I mill my current head until the grooves are gone I can use a gasket and my combustion chamber will be 34cc (including quench area I assume)?

On a side note, I am headed to pay for a membership now....thanks for all the information. If anyone is in Ky I'll happily buy you a cold beverage of your choice, but be warned I WILL talk your ear off...

Slimm

[TEXAS20225]

Slimm cutting your heads is a option but not if you want to go back, then you will be looking at cost to cu tyours then if your not happy you have to buy more heads, just dont get in no hurry no??? could not either when i was younger LOL look around for some they are out there

[Slimm]

I see many comments while I search concerning nickel bore and steel bore. How does one know which he has? Is there a year break that determines this or is it dependent on where the block was made or some other factor?

Slimm