Biting the bullet: T8pxrs

Post here for issues with outboard engines (i.e Yamaha 9.9) on PDQ yachts
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Page 83
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Biting the bullet: T8pxrs

Post by Page 83 »

I've ordered a pair of Yamaha High Thrust 8hp engines with power tilt. Your prayers or incantations will be appreciated. I'll keep this topic updated as the adventure continues. Anybody interested in some 900 hour year 2000 T9.9s? They are still running well, and have received a lot of new parts over the last 2 years.
Sandy Daugherty "Page 83" PDQ 36026
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Post by Lady of the Lake »

Best of luck. I would love to post any info on the http://www.pdq36.com website as you gather the data. We already have a document on fitting the new 9.9s and this would compliment that nicely.

On another outboard note, does anyone have a beater 9.9 that they would like to get rid of cheap or donate? I would love to tear one down and build it back up just for the experience. I am familiar with most systems on my boat but have very little experience with outboards. Any recommendations?
Sam and Gina Densler
s/v Lady of the Lake
PDQ36 Hull #15
Punta Gorda, FL
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T8 installation

Post by Page 83 »

The engines arrived. They were built in France! Bolted on the bracket for the controls and got worried: the gear shift cable attaches to the manual shift lever outside the engine cowl! Fears proved groundless, port engine popped right in, from above and from below, with more room to spare that the 9.9. Had to cut out about an inch of the fairing at the very bottom of the transom plate to accomodate the engine's slightly wider mounting plate, easily done with a jig saw. The control cable bracket extends four inches further forward, exacerbating the control cable bending problem of the past. Major head-scratching in progress. Lifting the lower end up manually revealed that these engines will tilt up out of the water just about as high as the 9.9's did.

The T8's have fewer cubic inches in cylinders, but turn an 11 3/4" x 5 1/2" prop, allowing them to turn higher rpms. I never had a tach on my 9.9's, so I have no idea if they actually reached peak power. Since I'm confident that Yamaha won't sell an engine that overspeeds at 7 knots, I'm hoping (read fervently praying) that the 8's will have enough thrust for punching into higher headwinds and seas because they can turn higher rpm on the power curve on demand, without overspeeding. We'll see.

The wiring harness has been changed from the old 7 pin plug to the newer 10 pin plug used by the NEMA 2000 engines. That's in spite of the fact that the under 50hp engines don't have transmitters for the NEMA data. There went another $80.00 per engine.

Today I'm going to repair some delamination in the starboard nacelle before we mount the starboard T8. Pictures at eleven!
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engines

Post by Mary Pamela Kilmer »

:D Please keep everyone posted on the results! Thanks, Rick & Pam
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Post by Page 83 »

I bought a used throttle quadrant on Ebay that has switches for trim and tilt, it came with newish control cables, but I would like advice on what cables bend in the tightest radius.
It got cold again here in Annapolis (freezing rain yseterday!) but I think I got the glass work done on the starboard nacelle. I had some spongy rot in the plywood inside that I dried out with acetone and injected with West Marine's version of GitRot. I stuffed all the voids with epoxy soaked glass patches and closed up with my best-ever layup, trying to keep the buildup pretty lean. If the temperature gets warm enough today I'll paint it, but I hope to hang the starboard engine on Monday or Tuesday. Then the controls.

Against the advice of wiser souls on this Forum, I'm going to try to use the Mini Tachs Yamaha sells for their generators and ATVs, called ENG-METER 4C-01, because they are small, cute, and say Yamaha on the cover.
Sandy Daugherty "Page 83" PDQ 36026
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bullet for lunch, advice please!

Post by Page 83 »

Both engines are mounted. It took an enormous amount of time to get the wiring harness straightened out, but everything works, with caveats. I have to travel for a while, and won't get Page 83 back in the water till the end of April. After that it wil probably take a week or two to get thru the recommended run-in times, so performance data is still a while away.
In the mean time, here are some observations.
the engines fit in the nacelles with only minor trimming of the bottom sides of the nacelles, aft ofthe transom plate. There are a lot of nice improvements over the original 9.9s; there is a manual choke that facilitates starting on a cold day. The external shift lever means you can control the engine if the cables or the binnacle console flake out. The garden-hose fresh water flush appears to put cooling water every where water gets in normal operation, and they are easily reached from above the engine. I may permanently plumb a freshwater wash with a salt-away mixer. The engines seem to be quieter. They can be tilted from switches mounted on the engines and from switches mounted in the binnacle. There is also a trim switch on one of the throttles, but I couldn't get it to work on both engines at the same time. I think it was intended to fine trim the angle of dangle of the engines for optimum efficiency.
Problems: The engine controls attach to an external bracket that extends almost too far to the starboard side, and five inches further forward that the 9.9s. The starboard engine's control bracket just barely clears the the boat's steering cables which intrude on the opening in the starboard engine well. With the engines tilted fully up, there is more bending forces on the control cables than before, even after trimming around the forward opening in the hulls above the nacelles. I've got to try to move the PDQ steering cables hard against the bulkhead with brackets, and I've got to find more flexible control cables. Suggestions?
Sandy Daugherty "Page 83" PDQ 36026
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Yamaha T8 PCRs on hull 36026

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Page 83 hit the water Friday and sailed back to Home Port Saturday. I ran the engines for a total of 3 hours at half throttle, averaging 5 knots sails down, with and into the wind. After a horific moral battle, I resisted the nearly overwhelming urge to just bump them up to 3/4 throttle, at least until the ten hour break-in period is reached. In any event, their performance seems to equal my 9.9s at half throttle, albeit quieter. I sat there with a huge grin on my face raising and lowering the engines with a push button!
With the hatches closed and the egines at half throttle, we could carry on a soft conversation at the helm. That's quieter.
I have my original numbers from the purchase survey, and will report a straight up comparison when they are PROPERLY run in.
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Guilty pleasures

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Last weekend was a bit light for sailing, and I put three more hours on the engines. Then my resolve broke. heading into about 4 knots of wind with the main up and against a max of a quarter knot of current, I inched the throttles up to full bore, and saw 5200 rpm and 6.6 knots, for one minute. Thats no better than my 9.9s, but its not much worse either. Mea culpa.
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The results: 0.3 knots slower

Post by Page 83 »

The trial is over, the numbers are in. Let the quibbling begin. With 10.5 hours on my new Yamaha T8PXRs Page 83 clocked 7 knots in calm water, no wind, averaged both ways. Full power on one engine netted just barely less than 5 knots averaged. Fuel consumption at full throttle is 7/8 gallon per hour, per engine. The max rpm was 5210, 300 rpm under advertised max torque. The water tank, gas tank, and holding tank were about full, and there were about 500 pounds of crew aboard. Sails were furled and covered. Theses tests were performed on an open course by an amateur driver, your experience may vary.
On the sea trial for my purchase survey in October 2003, Page 83 did 7.3 knots on the 9.9 hp engines
QUIBBLES: 1. The engines are still not completely run in. They may reach higher rpm later. 2. The lower part of the engine mounts drag in the water, and fill up the nacelles! I'll build a fairing around them on the next haul out. 3. I'm using those little tachs Yamaha sells for dirt bikes and generators, and I haven't compared them to a good dwell tach. However, if the engines really aren't turning 5500 I'll have a prop shop dial out a half inch of pitch. FINALLY:
It is just so incredibly wonderful to press a button, drop the engines, and know that I'm not going to have to buy yet another prop if the engines hoist themselves back into the cockpit when I want reverse.
Sandy Daugherty "Page 83" PDQ 36026
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T8 installation update

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Revise my full power speed down to 6.9 knots averaged. I'm still collecting numbers. There is a trick to compensate for the length of the wire from the little tachs to the engines: increase the wraps on the spark plug leads. Fuel consumption appears steady at .85 gal US per hour at full throttle per engine.

Did I mention how sweet that tilt button is?
Sandy Daugherty "Page 83" PDQ 36026
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Re: Biting the bullet: T8pxrs

Post by samtheskull »

Page 83 wrote:I've ordered a pair of Yamaha High Thrust 8hp engines with power tilt. Your prayers or incantations will be appreciated. I'll keep this topic updated as the adventure continues. Anybody interested in some 900 hour year 2000 T9.9s? They are still running well, and have received a lot of new parts over the last 2 years.
Hi, do you still have the year 2000 yamahas?
We purchased our PDQ 36 hull no.66 this year and I was thinking of keeping a spare motor or two.
Our boat is Sam the Skull (ask goole) and we look forward to meeting other owners.
All the best John Anderson
NEW OWNERS WE are now the proud owners of PDQ 36 Hull number 66.
We have named our boat Sam the Skull. ask google.
WE are John and Barbara Anderson from the Isle of Arran Scotland
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Post by Tanah-Keeta »

I have three 9.9 motors.. 2 are 2001 and 1 is 1996... all go for $400 each

If you are interested, call me at 1 252 940-0091
Ron McDaniel
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Re: Biting the bullet: T8pxrs

Post by Page 83 »

I've got ivy growing up the lower ends of my Yamaha 9.9s. Somebody make an offer!
Sandy Daugherty "Page 83" PDQ 36026
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Re: Biting the bullet: T8pxrs

Post by 36041 »

Sandy,

Can I get the wiring pin out information from you for the new 10 pin connectors on the new style engine? I suspect it would save me hours and hours while trying to put mine in. I am flying home this week, maybe we an get together and you can walk me through your install? Dinner is on me.

Tom
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Re: Biting the bullet: T8pxrs

Post by Page 83 »

I was late getting the boat back in the water this year after spending four months in Dallas with Family Issues. The T8's started on the first try, and kept running on old gas and fogging oil!. Motored back to South River at 4800 rpm, (6 "knots") and then opened them full for 5 minutes seeing 7.5 "knots" into mid ebb tide and 6knots of wind on the nose, bare pole. I was overly elated till I realized my new handheld gps was reading MPH instead of knots. Oh well.

Still waiting for Dinner, Tom.
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