Optimizing my setup

[badbass]

I havent been on the forums for a while now since the last time we fixed my motor I havent had any trouble since. I am now trying to get the most out of setup since I am a competative bass angler and I am trying to improve my top end speed.

My current setup is a 17.5 ft Thunderbird hull ( South African) this hull is known for it's speed and I am currently running @ 63 Mph (GPS) with a 200 Yamaha spinning a 25 Ballistic four blade @ 5200Rpm. I am trying to get my Air fuel Mixture closer to Stoich since I am running very rich at the moment and my plugs burn a solid black colour.

I allways clean and service my motor between comps and have been checking my Jet sizes according to the Service manual but I cant seem to find my specific model or carburettor ID in my manual.

First of all I need to know what my max rpm should be, and if I am running at the right rpm with my prop. and then if my jetting is correct?

My model: 200BETO/6G6/L404035
Carb ID: 6R401
Main Jets: 154 / 158
Pilot: 60
Main Air: 290


Does this jetting seem fine for altitude of 1700m

Thank you in advance

 

[steelespike]

Re: Optimizing my setup

Not a Yamaha expert ::
My manual doesn't have Engine model numbers.It also
only covers 84-89.It lists carbs stamped 6G600 for 1984,6G602-85-86,6G603-late 86-87,6G603-88,6G606-89.Manual doesn't indicate these numbers are model numbers.If your carbs are stamped any of these numbers I can give you the info listed.
As you probably know you want to be very careful about leaning your mixture,especially in competition.
My info says the 200 hp developes its' power at 5,500 rpm.Most shoot for 200 to 400 above developed rpm on your typical outboard.If you go over to the prop forum with your info they probably can help you pinpoint where you are prop wise.

 

[badbass]

Re: Optimizing my setup

Thanks for the info, I think I will stay a bit on the rich side since I might lean out too much if we have tournaments at sea leve. I dont think the performance upgrade will be enough to notice.

 

[deejaycee_2000]

Re: Optimizing my setup

that is very slow for that 200hp, I see you are up in Witbank, I'm in Cape town, I get at least 120kmh with my 200hp vmax on a 21 foot pinache with my 21 pitch power tech prop 3 blade, I would change the prop, a 4 blade is for power not speed, also make 100% sure your engine height and tilt is fine tuned, I see no reason why you shouldn't be able to get it up to 120kmh ......

 

[Ray Neudecker]

Re: Optimizing my setup

I would agree that more performance based on personal experience should be available with a different prop. I have found the Pro series Yamaha to be much faster than the Ballistic. There are many brands that will outdo the Ballistic in my opinion.
Hard to tell about the jetting but that sounds like one of the later model horizantal front half motors. I doubt that you are too rich for performance purposes. You need to prop for a top end RPM of 5800 or more. My prefrence for racing applications with stock Yamahas is 64-6800. RPM's. You have to disconnect the limiter to do this.
Racing set ups take a lot of test time and work if you want to be the king. Good Luck.