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Yamato cooling
Ok,Now I get it..and thank you all for your response.I really appreciate it!
Rich
Ok,Now I get it..and thank you all for your response.I really appreciate it!
Rich
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What do you mean by the inside diameter? Which size hose should be used?Originally posted by jsilvestriComment
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Side Note
As a side note about propellers, cooling, and Yamatos. The second year I went to Depue the Yamato team brought a pro Pugh "replica"
boat to the Nationals race and a professional factory driver (with rising sun ascot and all new driving equipment!). 
The factory team of engineers and crew technicians knew their motors better than we did, with the exception of our "special modifications" to gearboxes, blueprinting, balancing, some shaved heads to APBA minimum "specs" on the 102's and new 302's, ...and our wide variety of props. They were amazed at the speed we got out of their motors, and how high we run them. They spent days trying to get propeller information out of the US racers, with no success, crashed in testing (driver error) 
, and did not place in the final heat. A few years later they learned about the setup changes we made and our high performance prop sources, and they came back with a new driver to place (I think second) in 350 ccH! I didn't ask them if they had cooling problems in testing... 
All I know is my 250cc engine steams worse than my 102's, and I have gone to moly-coated pistons to reduce the over-heating effects! 
Semper Fi!
Al Peffley
15-R/R-25Comment
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Yamato cooling
I sent a BIG thank you to all who responded,But somehow screwed up,it never appeared.
I now understand the dynamics of whats going on,and why.If it wasn't for YAMATO,we would be where?I guess my remaining question would be,what was the factory YAMATO prop specs?I guess it was all the same for all the racers...What was the Diameter and pitch?
After all these years,it looks like the 302 is a turkey?What makes it an also ran?
Many thanks to all who responded...this is really interesting too!
Anybody like to discuss the black art of propellors?
Thanks guys!
Rich OliverComment
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I'll agree that there are many ways to make the 302 pump water better. Look at how the exhaust cover routes the water, and how you have you discharge hoses routed. Also, take a look at the inside diameter of your discharge hoses. Bigger inside diameter discharge hoses helps keep the motor from creating a vapor lock when the engine isn't pumping that well.
I do think that a lot of guys look at the height of the propeller shaft correctly. You should think about the height of the propeller shaft when you are racing. If you have a boat that airs out really well from front to back then your propeller shaft height is higher than when racing a boat that does not air out well at the transom. This makes a big difference when wanting to pump water all of the time.Joe Silvestri
CSH/500MH
Dominic Silvestri
JH/JRComment
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The 302 is NOT a turkey.Originally posted by Rich Oliverbill bComment
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Rich O.
A little advice..........Testing and racing conditions vary greatly. Chances are you will be able to raise the Yamato 102,80,or 302 to a height that may be fine testing but not work under race conditions. You have to keep an eye on the water pumping at a race and possibly have to lower the motor to be 'raceable' in rough race water. A lot of guys burn motors up by not making the adjustment at the races!
J-Dad
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Matt. Very true. We use a Digatron head temp meter on the hydro. If it gets to 425 degrees you are in the RED zone. Fact is we have not stuck a motor since we started using one.bill bComment
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cooling modification...........
would not a more simpler solution to the "cooling problems" related to the 302's, to just allow the inlet hole in the exhaust snout to be opened up more, versus adding a pickup, which will slow you down? Just amend the dimensions for the hole.........Daren
DSH/750ccmh/850ccmh
Team Darneille
sigpicComment
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I agree....but someone need to do just that, drill theirs bigger and test. Than get the test data to the SORC or come to LA with it so the SORC has facts to make decisions on. What if drilling the hole bigger leads to some other problem....Don't know what... but that is the problem with the SORC, most of the time they don't have the data so they are not willing to just make decisions.Originally posted by mercguy View Post"Ask anyone, I have no friends. I do have some people that put up with me and mostly because they like the rest of my family"
Don AllenComment
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11 years later, newest model Yamato same problem, very very Discouraging to a new guy just getting into the sportComment
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Seems to me that they were talking about solving the problem the same way that they are talking about now!! Was no one listening 11 years ago??
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Exactly the reason I made a comment to bring it to the top of the forum. So everyone could see that possibly this problem may never be resolved. Might be time to look at another class before I spend anymore money on a "stock" YamatoComment
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Sidewinders have impellers...
Ryan Runne
9-H
Wacusee Speedboats
ryan.runne.4@gmail.com
"Imagination is more important than knowledge"--Albert Einstein
These days, I find it easier to look up to my youngers than my elders.Comment
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