what makes the most differance

[Joe Raimondo]

What one thing can be done to a stock out board that will make the most improvement.Not the prop or the motor height what on the motor itself.The stock outboard racers hopefully will have a few good ideas.

[BLACKBIRD]

Cut the heads!!! wack them babies till there is nothing left of them. then buy you some high octane fuel and let err rip!!!
seriously,,,stock standard 2 stroke,,, higher compression will be the quickest and cheapest hp gain. but you have to get different specs for diff motoers and don't ever buy 87 fuel again or poof!!!!!

[Joe Raimondo]

How much would you cut off on a 115 V-4 yamahas heads .010,.020,.030.I run high test pump gas 93 oct. and woudnt want to run fuel.On a car ten and a half to one is about as high as you can go on pump gas with max.38 degree timing with cast heads.Im not sure what the deal is on a outboard.How much would you cut them without fear of not being able to run pump gas.

[Joe Raimondo]

With a increase in compression would you have to back off on timing ,What about jetting would that have to be changed.Who makes a high performance 2 cycle guide book I would love to get one but have not seen anything on 2 cycle outboard hop ups.

[northeastcat]

Joe,
What you need to do is to know how much compression you have right now , then cc the heads, make an educated guess , take off a bit and bolt it back on ,and take another compression test , and repeat. Your goal should be no more then 150 psi. compression , unless you want to run race fuel.

[Joe Raimondo]

So 140 would be a safe max comp.reading for pump 93 oct. gas

[BLACKBIRD]

150 psi should be safe on 93. when you get it together go and run it hard for a stretch. bringing your spark plug tool with you, it is best if you can shut down the motor at wot. but be sure that you can do this safely. pull the plugs and look at them. look at the ceramic (white area ) it should have a tan color. if it is white you are too lean and you will have to get bigger jets for you new hp. also with a manafying glass look to see any aluminum particals on the plugs. if there is you need to go slow back to the dock. this would mean bigger jets or more octane. backing the down the timming is not ness. but do not advance it either. good luck!

[Joe Raimondo]

Blackbird ,Thanks for your advise and time.I think I will save the stock heads and play with another to get it right then do a plug check and make sure that we dont lean out.Thanks again Joe R

[Superdave]

if it is white you are too lean and you will have to get bigger jets for you new hp. also with a manafying glass look to see any aluminum particals on the plugs. if there is you need to go slow back to the dock
Good advice ??? :confused: Think not.
DAve

[BLACKBIRD]

Now thar's a helping hand for ya. lets see what Super???? would give you for advice??? ---- ------ ------ ------
------ -------- ---- ---- ------- ahhhh nothing I see. One of those better to say nothing then to remove all doubt kinda things.:p

[Superdave]

I would be REAL concerned about aluminum on my spark plugs. I'd say you were lean alright. You do a WFO shut down and find filings on your plugs you better do more than change jets. I'd make a little guess and say the pistons melting. :eek: :eek:
Dave

[BLACKBIRD]

that is why I said to go to the dock. I figured that needing to change something would naturally follow

[Superdave]

to jet it rich and work down. If the pistons start flaking it ain't gonna get better!!:eek: Might not make it to the dock. :cool:

[Joe Raimondo]

To put a stop to this between Super Dave and Blackbird,Hydra-Tech will tell what jet change should be made if you install there rec. head.You are correct Super Dave rich is safer and lean is fast and scary and you cant change damage after is has happend.Blackbird was helping with some friendly advice .Thanks to both of you for the help.

[Superdave]

difference in opinions. :rolleyes: Most of these guys are out for TOP performance and have a lot of spare parts and money to buy new. I'm a poor boy and don't want to ruin my junk. :D I would rather spend $20.00 on new jets and be too fat than to ruin a piston and have to rebuild. Good luck.
Dave

[Joe Raimondo]

Yes same here Im not trying to break any speed records I got a shallow water flats boat for back country fishing and want all the performance that I can get out of it and still be able to use it more than work on it.I dont mind someone faster unless they have the same set up .Cant stand being outrun with equal boats.Thats why I always want a little edge.I really appreciate the help and advise thanks again.