HPBCANADA.COM

Reason for asking?
This seems to be a good buy......could be reworked for a Mercury, Yamaha or Tohatsu.

https://www.ebay.com/itm/13-Spline-Sign ... 0012.m1985

I'm hoping to see 80mph top speed, and maybe 75mph average over the kilo, Rolf reckons he can get 350rpm from the engine. My problem now is that all the record classes are changing in the UK so I won't have a class. Looking into maybe attempting an APBA kilo record for X class SLT, not sure if they'd be happy with a Scotsman breaking an American record in the UK though

Do top world speed records take into account salt water vs fresh water, different altitudes, humidity and temperatures...or is it simply the highest recorded number is given the crown?

So let me try to understand this......You have posted on other sites that your current set up runs 58 knots [68 mph] with an 18 pitch.and one person in the boat.......now with a Rolf legal S850 70CES powerhead you are going to run 80 mph with two people in the same boat and set a world record.....seems impossible to me!

Don, looks like he is at 74-75mph a few months ago:
http://www.rib.net/forum/f50/my-thunder ... post785783

Thanks Matt, I had not seen that.
Successful time down at Coniston Powerboat Records Week. I’ve been out every day except Wednesday, which I spent re-tuning the engine to squeeze a bit more out of it. On Monday I got 62.79 miles per hour, 63.65mph on Tuesday, 67.83 on Thursday and after three runs this morning I hit 69.99mph twice, and then reached 70.10mph, faster than the existing world record of 67.47mph. Hit 74.9mph on one run today!

AND HE HAS 2 PEOPLE IN THE BOAT.

The problem I have is the reference of this motor being a 70CES. The 70CES is a SPEC motor and as such EVERY spec on the spec sheet must be followed. ANY change from the specs and the motor is NOT a 70CES it is a MOD 70. Even the custom tuner makes the motor not a 70CES. With the correct label MOD 70 the motor can be a bit MOD or very MOD. The latest MOD 70 Yamaha is between 58 and 61 cubic inches. It has different sleeves, pistons, enlarged 90 hp carbs, modified ignition system and porting similar to a 60DES. It produces over 115 hp @ 6500 rpm and turns over 8000 rpm.
This at first sounds great and even though the MOD 70 Yamaha is strong.......the problem is the COST and the fact that for FAR less dollars you can build a stronger 56 OMC. How fast are these MOD 70 and MOD 90 motors? Between 65 and 71 mph in 660 feet ...there drag boat motors.

THE CURRENT APBA RECORD FOR X CLASS
This is the one I found. STEVE CAN YOU CONFIRM?.
SLT EXPERIMENTAL KILO
67.13 MPH 4/5/2006 CRESCENT CITY, FL
BY: EVEN GOLDBERG
HULL: AQUARIUS
MOTOR: MOD YAMAHA

The 67.47 mph is Production stock free hull.
SO YOU ARE IN VERY GOOD FORM TO SET THE APBA RECORD.

I always found this thread very interesting since I had purchased BRAND NEW in the original box a 6J2 Yamaha 70CES in 1996.
https://www.screamandfly.com/showthread ... -70-Yamaha

I had my motor for 10 years when this thread appeared. They really had no idea about the 70CES . They were building crazy MOD 70 Yamaha motors, some 1000 CC and even an EFI 70 Yamaha. One person on the thread set the APBA record that same year as mentioned in the above post. Yet if you compare their MOD APBA record to the UIM STOCK 70CES record they are basically the same.

Here are a few corrections and confirmations:
70CES first model appeared in 1984.....CES stood for competition electric short....it was not a tiller pull start....in later years Yamaha started making commercial non oil injected 70 hp models called 70C and the "C" was for commercial. Last 70CES was the 1990 model.
A 70CES was rated at 70 hp at the prop at 6400 rpm......so their close at 6500 rpm
A 70CES can run mid to high 7000's with out the ignition failing....only 2 props came with a 70CES...a 19 X 11 and a 21 X 11 ...both thru hub cleavers......the ignition does fail running over 8000 for long terms.
They were running too small jets in their 6H3 carbs.....70CES ran 90 hp jets in the smaller 6H3 carbs....The original 70CES carbs work better than the 90 hp carbs provided you have the 70CES jets in the carbs. If you do porting or mod the powerhead you may need 90 carbs, but you likely will not see any performance advantage over the original motor.
You have to weld the crank to keep the crank together and keep motor timing.
Put 200 lb compression and the motor goes slower......150 to 165 is best
A 70CES is a parts add on fishing motor with a heavy 10 kg crank [22 lbs] and rod assembly.....nothing special

New martinsville records 2013 ... page 15 ... https://issuu.com/apba.racing/docs/dece ... ssuuupload

SLT x-class sst60 70.445 mph 1/4 mile

New Martinsville records 2014 ... page 15..https://issuu.com/apba.racing/docs/prop ... 2014_issuu

SLT Bandit 40HP 58.808 mph 1/4 mile

Thanks Steve:

The SLT Class and T classes have had similar speeds for several years.
SLT with 850 Yamahas ran 67 as did T850 yamaha.

ITS THE 750 classes in SLT and T750 that have really changed:
In 2010 the S750 record was held by an SLT hull Tohatsu .....56.80 MPH
At the same time the T750 record was held by a Tohatsu ......55-56 mph

In 2013 the T750 recorded jumped still with a Tohatsu..........66.69 mph
In 2015 an SLT Pro Stock Tohatsu ran................................. 62.99 mph
Also in 2015 an SLT MOD 750 Tohatsu................................. 71.35 mph. THAT IS IMPRESSIVE!

Now with the new 3 cylinder Drag Class in Ontario this year....the 43 cubic inch Tohatsu has a lighter weight advantage and with MODS this motor looks like it can compete with the larger motors. BUT 20 lbs is not that much...like the 80 lb advantage between the other two groups.......NOW at 600 lbs the 750 class would get interesting.

TRIPLES CLASS
4. Post-race minimum weight, based on cubic inch:
a) 42 to 44.9 c.i. 780 lbs
b) 45 to 62.9 c.i. 800 lbs
c) 63 to 86 c.i. 880 lbs