C60 Yamaha Performance Upgrades

G3Boats

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Joined
Apr 21, 2007
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14
I have a C60 Yammie on a 2002 G3 Pro 175 aluminum boat and every post I have read on other forums on my rig indicates speeds ranging from 36-38 mph. My top end with a full tank (21 gal) me and my gear is 32.6 GPS at 5500 rpm. My cavitation plate is even with the bottom of the hull.

1. What are any comparable rig owners experiencing?

2. I have received conflicting advice on whether a SS prop would make any difference. A Yamaha rep told me that on my rig there is insignificant "flexing" on my 13 1/2 x 15 prop and not to waste the money on SS. Other prop sources say it will make a performance difference (maybe to sell a prop). Can anyone comment on this?

Any advice on performance upgrades will be apreciated.
 

finlay

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Joined
Apr 22, 2007
Messages
26
Re: C60 Yamaha Performance Upgrades

ss is better for proformence dont let any one tell u different, The only reasons outboards are sold with alloy props is because there cheap and if u hit a rock at speed the prop brakes and not your gearbox.

I would be running a higher pich prop maby a 14-15 , u can go ally or ss, the ss is going to give u better proformance than the ally but if u are strapped for cash and ally prop with a higher pitch should do the job. The beauty with ss u can mod them in many different ways to suit u down to the ground.

On the other side of the coin if its a fishing boat and u also use it to tow the kids round on the tube i would leave it as is.
More speed = bigger pitch prop

bigger pitch prop= a decrease in rpm at wide open throttle and slower punching on the plane.
5500 is the sweet spot for revs at wide open throttle if u pitch up in prop it will drop so u then might have to lift the motor which will give u better top end but cavitation getting on the plane and cornering.

it just goes on and on hope this helps.
 

WillyBWright

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Dec 29, 2003
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8,200
Re: C60 Yamaha Performance Upgrades

Is that a High Thrust model with the large gearcase? That diameter sounds high for most 60s. The ones with big gearcases are for heavy pushing, not planing. They'll plane a boat like that, but it won't be as fast as one with a standard gearcase. I'd say a good 6mph slower. If you have one of these heavy duty units, you won't get a huge performance increase by going stainless, but you'd notice an improvement.

I see the 2-stroke 60s use the large gearcase, and the regular 4-strokes use the small gearcase and high Thrust models use the large gearcase. I think that what's slowing you down compared to other 60s is that large gearcase.
 

G3Boats

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Joined
Apr 21, 2007
Messages
14
Re: C60 Yamaha Performance Upgrades

WillyBWright, I don't have a hint on the gearcase. The boat is a typical modified V hull bass boat, but the prop is stamped "13 1/2 x 15 K" and it came on the motor. The complete motor designation is C60TLRY and the max RPM is 5500.

Thanks for the input.
 

NelsonD7004

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Joined
Apr 24, 2007
Messages
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Re: C60 Yamaha Performance Upgrades

G3Boats, you inspired me to register on this forum and reply to your post. I have essentially a comp ratable rig as yours. I have a 2004 G3 1756DLX SC deluxe john with the C60 Yamaha. I have experienced what you have talked about.

Currently my rig is hitting 34mph (GPS) with the same prop as yours at 5500. Generally my load consists of 21 gal of fuel, shad tank, kicker motor, and the few other essentials for fishing. I have experimented with a few different props, but not any SS's. I have tried the Yamaha 17 and 19 pitch aluminums and 17 and 19 pitch comprops. To be quite honest I haven't seen much change from what the 15 is giving. On the 19's I generally would pick up 1 mph, however my RPM was just a fraction at 5000 rpm. I felt this was bogging my motor so I went back to the 15 to keep me at or near WOT. I have consulted with G3 and they told me that the 15 pitch was recommended on my rig, but did say that some people have been better suited with a 17.

To be honest I really don't think you will se much more than what you are getting right now with the aluminums. Perhaps the SS's will be another story.

Hope this has shed some light on my experiences. Happy boating.
 
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