Yamato pipes question

[STEVE FRENCH]

Also keep in mind,....They are run'n a huge Merc carb>>>>> https://hydroracer.net/forums/showthr...121#post181121
Anyone recognize that carb part number.....Year/HP Merc for "Junk Yard"/E-bay hunt'n????

[Little Fork Runner]

pipe/tuning

Hi I have been working on the pipe for my 302 and it is turning out pretty good. i got a few questions about the tuning. basically what am i going to have to do to tune it to run good. i am getting a tach this spring. i want to get my motor running perfect right around the 6600rpm peak before i put the pipe on. once its all good i will switch over to the pipe. will i have to adjust the carb and the jets, and also adjust the timing of the motor??? my pipe is being set up to slide so i can also adjust it that way to fine tune it that way. from what i here with the tuned pipe it will be running around mid 7000rpm will i have to tune it to a certain rmp that i want to achive???
Thanks for any info possible!!!

[GrandpaRacer]

Be aware that a megaphone pipe will be very loud and piss off your neighbors.

[JippeFIN]

I'm going to make two pipe for my yamato. These pipes are tuned to 7000rpm.
Stinger ID, bellyfact k2, kh and temp. I need some advice with these?

[JippeFIN]

Is this better than those above? This one is tuned to 6400 rpm..
Send me a pm if you dont want to comment public.

[johnsonm50]

As a C racer I will say that 65 is not bad, in fact -very good for a boat not running against other C's to compare. I've done alot of 'rear guard' in C running around 63-64 & have done well on good days at about 66-67. I know some guys run what seems like it must be 70+ in stock but don't really know if they are. Incredible driving might explain some of it.

[JippeFIN]

Rolled cones

[JippeFIN]

Ready for testing

image_41053.jpg image_41054.jpg

[JippeFIN]

I used permatex supra copper rtv silicone to seal plate and filler block, is it ok?

[ZUL8TR]

Do you have a tach, what type ?
What props do you have? Pitch and diameter specs and pics?

[JippeFIN]

I have tach, it's like tiny tach. Dewalt prop which is in place and two ron hills and those two blades also

[JippeFIN]

Do you have spray shields on pipes? This wasnt work as expected, 6000 rpm no more. Same setup with stock pipe it turns 6400 easily.
Maybe pipe support wasnt rigid enough, welding seam cracked and pipe is broken now.