Picco P-45-R Marine (Drum Rotor)

[Jerry Wyss]

I was wondering if anybody has had trouble removing bearings from this motor.

The original set was replaced really early in it's use,,they wouldn't come out with

my usual metheods,,I tried all I knew. Finally I did something I didn't want to do,

I located the area on the outside front case where the outer race of the main bearing would be and drilled two holes small enough to be tapped for a 4-40 screw.

I knocked the bearing (rear main) out that way and installed new Boca bearings

along with two 4mm long 4-40 screws. The bearings went in hard even though

I had the case heated and the bearings frozen. I've had to replace them again

recently and they still had to be drivin' out with a punch but I'm using Swiss units

this time. All in all this engine has a total of around 50 minutes of run time,,It runs

real strong but has short bearing life , to be sure. I've had a fair amount of time

running model engines,,but this is odd. Jerry (It's the Blackhead)

 

[warlokboats]

jerry i had the same problem with a 21 n/r. i took it to work and found that the bearing bores were ot in line. this will cause the bearing to run on an angle(to say) to the centerline of the crankshaft. he only fix i found was to replace the case. not good news in your case.

hope this helps

jon

 

[Jerry Wyss]

Jon, Thanks for your reply,,,I thought the same thing many times but have no

way to check it to be sure,,The guy I use with skill and equipment moved away,

so I don't know what to do unless just run it some more with the Swiss Bearings

and hope for the best. Jerry

 

[Preston_Hall]

If you are having to drive the bearings in while heated/frozen then it sounds like the bore is too small.

Bearings not being in line with each other will cause premature failure but not difficulty in installation. I have seen the NR bearing installation/alignment tool and I really don't see how that could happen on a NR. But things happen.

Upon installation, drop the crank in while things are still "loose". This will aid in bearing alignment. In your case Jerry this doesn't seem possible.

 

[Jerry Wyss]

Thanks Preston, Most engines I've changed bearings in, they do just fall in when

case is heated and bearings frozen and you can slap them out using the reverse. Not this engine,,I do use the crank to align the bearing and get it started and tap

the crank out (doesn't always work) but you have to drive it perdy hard with the

right size socket to make it seat,,,too hard I think.

jerry

 

[Terry Keeley]

I've found many of the bearing bores a little tight in the Piccos, result of tolerance allowances I think, ie: better a little tight than a little loose.

I've taken some 320 wet/dry paper and wrapped it around something close to the bore size and "massaged" the fit a little. I think as long as the sandpaper is tight in the bore so it can't rock the hole should stay pretty round.

If the case is heated so it's just a little too hot to hold, the bearing should slide right in, at least that's how I like them to fit. When it cools down and the bearings are clean of all oils and greese there should be a couple of thou end play in the front bearing and it should go forever when spun.

 

[Don Ferrette]

Terry's right about the fit of bearings in Picco motors. When I ran the EXR's the bearings were always harder to remove than any other motor I've ever run. The late Tom Grannis once told me that when you remove the bearings if you see ANY residual coloring/staining in the bearing area from oil and/or additives (ESPECIALLY castor) it HAD to be removed as that thin film would make it a real pain removing & installing bearings & it would get worse with each bearing change as that film layer increased. :huh:

 

[Jerry Wyss]

Thanks for your input Guys, I going to secure a good inside measuring devise and

take several measurements and see if a "Plumber" can find out whats going on

here. Does anybody know what the "Bore" vs Bearing OD difference should be?

 

[Terry Keeley]

Thanks for your input Guys, I going to secure a good inside measuring devise andtake several measurements and see if a "Plumber" can find out whats going on

here. Does anybody know what the "Bore" vs Bearing OD difference should be?

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I'd be interested to know if you can come up with some accurate numbers. You'll probably need a fairly expensive bore gauge that can check into blind holes, my "standard" type Mitutoyo set works great in sleeves but can't do bearing bores. Know any good toolmakers?

I'm sure you culd find all kinds of info on bearing fits, I'd check the latest "Machinery's Handbook". I'd bet for our application we don't need an overly tight fit though as our cases wouldn't get as hot as say a pylon motor. Those guys seem very concerned about fit as the case gets quite hot during a run.

 

[Jerry Wyss]

Hey Terry, when you said that,, it hit me,, I use a silicone mould product,,one type

I used to make that cowl on my avatar,(avitar?) of my Sport 60 Pennzoil Boat,,

My supplier has a much harder type that should be measurable. Just plug the hole

where front part of the crank shaft goes and pour in the silicone where the main bearing goes. This silicone won't stick to anything, so it would push right out,, Blink,, Blink;; Whataya Think

 

[Terry Keeley]

Hey Terry, when you said that,, it hit me,, I use a silicone mould product,,one typeI used to make that cowl on my avatar,(avitar?) of my Sport 60 Pennzoil Boat,,

My supplier has a much harder type that should be measurable. Just plug the hole

where front part of the crank shaft goes and pour in the silicone where the main bearing goes. This silicone won't stick to anything, so it would push right out,, Blink,, Blink;; Whataya Think

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Now there you go, a perfect example of "lateral" thinking, awsome. It would be much easier to measure a "plug" of some kind with a micrometer than to measure the bore itself. The plug would have to be rigid enough to measure though.

I'd think if you waxed the area properly and used some PVA you could fill it with a mixture of epoxy and silica and get good measurements that way. Or possibly the silicones you use are rigid enough?

 

[Jerry Wyss]

Keeley,,Keeley,,are you the one that makes head buttons for K&B engines??

If so, I have a mod 7.5 K&B thats needing a head button , that has printed

"B 95 7.5" on the engine mounting lug,,do you make one for this motor??

As to your reply,, Thank You for the Good words,,, such coments are Rare

these days. I'm gonna call Stephenson Pattern (supplier) and find the right

stuff for this kind of job,,cause you wouldn't want to have an error here.

Thanks again Terry

 

[Terry Keeley]

Yup, that's me. Those K7B 3.5 and 7.5 heads are our most popular models, I know you'll see a noticable improvement with one. Gary Preusse has them, 630-279-2451. End of shameless plug.

Please keep us informed when you get some numbers, it'll be very interesting. I have a copy of the "Machinery's Handbook" and will look up all the specs when you get some measurements...

 

[Jerry Wyss]

WELLL Doggies, It's Been a Red Letter Day for me,,Nice runnin' into ya Terry.

I pushed this 7.5 over a what I had before with the addition, of all things, a check

valve in the tank pressure line due to a low (tanks) situation in realation to the

carby (as the Ozzys would say). It came alive then,,but needs a little more to

keep up with the faster boats around here. Motor is in an old Aerotech hull that I

bought many years ago and never used and haven't run yet. Motor was in a

endlessly modified Bandit Killer which in my opinion was never intended to be

used with a modified motor,, The boat was named "EVIL", and it earned it's name.

I'll let you know about the measurments,,Thanks alot for your help,,,Awesome

Thing, Intlwaters. Jerry