port'n'polish

[andrew k]

i had my 20hp merc apart last year(split the block) was planning on porting exhaust and fuel. i ended up just polishing what i could reach. i wasn't sure how acurate i had to be when porting. so i just polished anyone have any numbers for me when it comes to porting. year 2000 mercury 2 stroke.<br />any help would be appreciated<br />atk81

 

[andrew k]

Re: port'n'polish

^

 

[andrew k]

Re: port'n'polish

^

 

[MercFan]

Re: port'n'polish

No info from me sorry. I generally go with: If merc could get more horses without sacrificing something, they would've done it.<br /><br />But porting on 2 strokes has been around for as long as 2 strokes have been around, and positive results are achievable. Same thing with 2 stroke exhaust tuning. I hope you get the info you're looking for! Good luck! Lemme know how it turns out!

 

[WillyBWright]

Re: port'n'polish

About all you can do is clean-up any sharp edges on the reed block and match the intake manifold opening to the carb bore. I doubt you'd gain more than a tiny fraction of a horsepower. There's nothing you can do with the exhaust I'm aware of.

 

[Laddies]

Re: port'n'polish

The major differance from the 20hp and the 25hp mercury engines is the tuning pipe under the powerhead and carb jetting

 

[andrew k]

Re: port'n'polish

any more info on the tuning pipe? a couple people on iboats have mentioned it to me. i'm sure if you could explain it to me i'd understand what and were it is. i did have my motor apart.<br />thanks for the info<br />atk81

 

[andrew k]

Re: port'n'polish

^

 

[Laddies]

Re: port'n'polish

atk, I just went to the BAM Marine parts site and cked seems on the newer engines the tune pipe is the same on the 20 and 25 but differant on the 18hp if you want to take the time and ck the actual differances in the 2 engines you can go to their site and compare part numbers sorry about thr wrong info--Bob