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WHY THE 60 hp 3 cylinder, big foot would run mid pack in T750.

If the powerhead was a 75 hp [at the crank] or 70 hp [ at the prop] I think they could be TOO competitive.
Even at 725 lb minimum.

IN VP75 when they allowed the 2 cylinder OMC in the class.....the twin was the better option.
2007 Kustom Camo 13' V We raced this boat one season and were undefeated with it. Was 2008 High point champion. With a 2 cylinder 60 hp motor it outperformed the competition running 75 hp 3 cylinder motors.
https://www.collectorboats.com/s/cc_ima ... 1364166202

The 49 OMC and 52 Yamaha 60 hp models will have more punch, but the big foot will hurt them top speed and handling.
We have lots of history with lake boat Voodoo's, a 13 foot Checkmate and a very heavy Critchfield.
The quickest was the Critchfield and it ran a 75 hp [at the prop] . It was competitive with Jakes 57-58 mph Delta OMC 60 hp twin.
https://www.youtube.com/watch?v=vdsi1bARVZc&t=15s

Our current top T750's run over 60 mph, so a 60 hp bone stock [at the prop] 49 or 52 triple will be less competitive.
The current sleeper in T750 is the 49 twin carb Mercury.

Racing motors with different performance characteristics in the same class has always made FE/EP/FV/T class more interesting to watch and helps to eliminate the PARADE type racing .

Don, If the 49 cid Merc is legal in T-750 then shouldn't the 49cid, 60hp triple OMC with small carbs be legal? Same cubes and same hp. To promote T-750 & make heavier drivers like me at 230 lbs. be competitive, the added torque of the 3 cylinder would help. My rig race ready with driver is 780lbs. That is more than T-850 allowable weight. We have drivers that weigh 138 lbs., with race ready rigs at less than 600lbs. If you look at the current entries in T-750, nobody weighs more than 178bs. except myself. My grandson Matt is now 21yrs.old, but won't run T-750 because he weighs 255lbs. We won't let him run T-850 due to Todd's accident.

Your thoughts, Thom

Thom, OPBRA is willing to look at any combination and provided the outfit meets the safety rules they will allow the boat to run in the class it is most competitive in.

[quote="craig737"]Right you are Paul! Every effort will be made even on race day to have all arrivals on the water.....there will be nobody watching from shore if I can help it. Anybody...especially newcomers...can always contact me with questions or if looking for parts or equipment. If I don't have the parts or the answers I'll get them in contact with somebody that does! Thanks![/quote]

Even with your weight disadvantage you currently are a top 3 boat in T750. The Le Mans start hurts you the most.
The key with the OMC and Yamaha 60 hp triples is the lower unit.
If OPBRA allow the triples to run with a big lower unit and with your experience I think you would still be top 3 but with a better chance to be number one.
I think the 60 hp triples with a nitro case would be too strong especially if the motor is race prep.
My idea with the 60 hp triples was bone stock, no race prep, low cost. Make it easy for people to try racing.
It's still GREAT FUN to race for 4th, BUT, let the top 3 be true T750 boats.
My suggestion is, put together a BONE STOCK OMC 49 and come to the race with both big and nitro lower units.
I am sure if it makes for better racing for the fans, OPBRA will look into allowing them.

Thom, I am going to make another suggestion.

We want to keep T750 centered around T750 motors.
If we allow the larger displacement 60 hp triples with big lower units racing at 725 lb minimum that doesn't help the heavier drivers whose outfits will weigh more than 800 lbs.
The 140- 160 lb drivers will run at exactly 725 lb and they still keep the same advantage.
AND YOU RUIN T750.

So my suggestion is:
If you want to run one of the larger motors the minimum weight is 850 lb.
That equalizes the playing field.
With the 594 lb minimum for the smaller motors, the lighter race drivers will run their current motors.
History shows the advantage is STILL with the pure T750 motors.

Plus it gets the non raceboat VooDoo's, Checkmates, Allisons, Sidewinders etc into T750.

MY RULE BOOK WOULD READ:
6. Motors:
a. Production Stock And Altered Stock 40 to 60 hp
b. 2 cylinder models up to 849cc................................................594 lb. minimum weight
c. 3 cylinder models up to 750cc................................................594 lb. minimum weight
d. Mercury 3 cylinder [twin carb] up to 49ci................................725 lb. minimum weight
d-1 OMC and Yamaha [6H2] 3 cylinder 60 hp up to 849cc...........850 lb. minimum weight [must run large lower unit]

SO WE HAVE ADDED BOATS TO T750 AND NOT HURT THE CLASS.
Also with the younger 12 year old drivers a larger boat say 15 foot Allison 49 OMC would be a safer boat to race in T750,

In this theoretical rulebook, what would the compression limits be for the larger 3cyls?

d. Mercury 3 cylinder [twin carb] up to 49ci................................725 lb. minimum weight
e OMC and Yamaha [6H2] 3 cylinder 60 hp up to 849cc...........850 lb. minimum weight [must run large lower unit]

still 160psi?


I like the idea of include more motors but keeping their performance in alignment with the class.

Here you go Matt:
6. Motors:
a. Production Stock And Altered Stock 40 to 60 hp
Class max is 60 hp....so no 70 hp parts unless the same part is on the 60 hp

b. 2 cylinder models up to 849cc................................................594 lb. minimum weight
c. 3 cylinder models up to 750cc................................................594 lb. minimum weight
Same as 2019 rules

d. Mercury 3 cylinder [twin carb] up to 49ci................................725 lb. minimum weight
I increased the weight to 725 which is T850 weight...160 rule still applies but block design limits compression to 145 to 150 lbs.

e OMC and Yamaha [6H2] 3 cylinder 60 hp up to 849cc...........850 lb. minimum weight [must run large lower unit]
Craig Fraser's Critchfield was a 75 hp OMC large lower unit, it weighed approximately 850 lbs and was competitive with Jakes twin.
By having the same basic motor run the smaller carbs we slowdown a 850 lb boat . 160 rule would apply but with no motor mods allowed 145 to 148 lb compression is best. This combo will run 57 to 58 mph.

Yamaha [6H2] 3 cylinder 60 hp
No 70CES parts period and no 70 hp parts unless they are common with the 6H2 model. 160 compression rule applies but you cannot cut the 6H3/6H2 head to achieve 160. At 850 lb weight this a 54 to 56 mph combo.


60 hp OMC parts list
https://www.crowleymarine.com/johnson-evinrude/8753.cfm

60 hp [6H2] yamaha parts list
https://www.boats.net/catalog/yamaha/ou ... 95/p60tlht

Matt here is the big lower unit yamaha drive shaft part number
6H3-45501-00

https://www.megazip.net/zapchasti-dlya/ ... 5501-00-00

no motor mods =
no cutting of head.
no mods to exhaust tuner whatsoever. no exhaust tuners from other models.
no changes of any type to intake tract (ex: no removal or change of reed stop height)
no use of any parts other than those that came from the factory on that motor.
no removal of any parts to reduce engine load or reduce engine weight.
no speed increasing decnals or speed holes.
no fast colours (ex: yellow)

Matt, I didn't change the other 2020 rules
e. Low emission and 4 stroke models are encouraged.
f. All motors limited to 160 psi compression
g. Rev Limiters may be raised or removed
h. Any combination or configuration of factory available parts.
i. Aftermarket parts must be direct replacement
j. Air intake may be modified, must retain stock carburetors
k. Minimum 15" midsection

You could read these rules as you say.
NO MODS
EXAMPLE: If the model you run came with 120 lbs compression in stock form that's the way you must run.
And the previous ANY tuner rule is gone,,,,as are the engine blueprinting and balancing rules.

h. Any combination or configuration of factory available parts.
This too....is not a alteration but rather a rule to make more STOCK parts available.

k. Minimum 15" midsection
You would be using a different model's parts to do this.

Matt, you also have first hand experience with the 70B long shaft VS the 70B long shaft with the small lower unit VS the 55 hp twin long shaft with a small lower unit all on the same VooDoo.

For the YAMAHA people....a few 6H2 60C models show up once in a while. The 70B 6H3 are more common.

So to convert the 70B to a 6H2 you need
6H2 Reed stop plates
https://www.ebay.ca/itm/1997-Yamaha-60T ... 3A&vxp=mtr

6H2 carburetors
https://www.ebay.ca/itm/Yamaha-Outboard ... R7&vxp=mtr
You need to compare your model 6H3 with the 6H2 carburetors......I think jetting is the only difference.

That's all you need to do for a long shaft.

A nice final touch...the cowl
https://www.picclickimg.com/d/l400/pict ... linder.jpg

FOR A 15 inch short shaft...these are the original 1992 part numbers..most are updated due to change in colour.
Complete lower unit
6H3-45300-02-EJ

Mid-section
6H3-45111-00-EJ

Muffer for a 15 inch mid.
6H3-14711-00-9M

6H3 Yamaha Pro 50 power trim bracket assembly
Trim unit must read 6H3 not 6H1 the 6H1 trim unit does not fit the Pro 50 clamp brackets

The other parts are the same as the long shaft. You could buy the water tube, it's the same part as the long, just shortened.

I don't think I have a really good back to back comparison to take meaningful conclusions from.. Setup has evolved over the past few years, and the 70hp motor I use on the Voodoo is now a different motor than when I first ran it with a large case. (if I remember correctly, prev owner ran a Yamaha drag 14x22, at 55mph. And when I put on a small case and a un-worked Ron Hill semi-cleaver, I saw 55.5mph)

I'd say though that a Yamaha 70hp 2stroke is not a strong 70. I think Tom's Merc Formula Race 60 is stronger (2 or 3mph faster). Not sure how Dok is seeing his speeds (don't know his mods). My 70's are old and stock. Actually, I think Dok's top speed and Tom's are the same?

I'd have no problem saying that an untouhed Yamaha 70 2 stroke (large case) is slower than the top T750 boats. My voodoo with a 1987 70hp and a small case sees 61, maybe 62 on a cold crisp day.. Heavy hooked boat though.