Bearings for 7.5 K&B

[aussieboater]

Does anyone know the specs on K&B 7.5 outboard bearings

Thanks

Brad

 

[RaceCraftBearings]

For the motor you need an R6 and a 6903. For the PTO you need 2 - 608's.

Ron

 

[Geraghty]

Does anyone know the specs on K&B 7.5 outboard bearings

Thanks

Brad

It depends on the 7.5 outboard you have......

The "older 3 piece case" 7.5 OB [#8701] used the cast carb and the thin flange front housing,that was .175" thick and the front housing did not support the larger rear bearing in the front housing.This motor used the B15-R8[15MM I.D.X1.125" O.D.X.250" wide] rear bearing and the R-6[.375" I.D.X.875" O.D.X.218" wide] front smaller bearing.

The "newer 3 piece case" 7.5 OB [#8702] used the 9400 series billet aluminum carb and the thick front housing flange [approx. .350" thick] that partially support the larger rear bearing in the housing.This motor used the 6903[17MM I.D.X30MMO.D.X7MM wide] rear bearing and the same R-6 front bearing.

The "newer 3 piece case" air-cooled 7.5 outboard [#8703] uses the same bearings as the 8702.

The 7.5 "PRO" one piece crankcase 7.5 outboard motor uses the same bearings as the 8702/8703 motors.

 

[Jerry Wyss]

Thanks for that Rod, for the first time I know which 7.5 I have (8702) I had to print that page

 

[RaceCraftBearings]

There are very few of the old serial numbered motors that require the B15-R8 around however I have supplied a few boaters with that set. The majority have the 8702 and newer motors. Rod just likes to show his age

 

[rmprecision]

Hi Aussie

I got my bearings for my K&B of RON.

A great guy to deal with and will ship fast to Australia.

These bearings are a bit pricey but well worth it.

My motor run heaps different now it's not sucking air

Get yourself a new set and you cant go wrong.

Jason

 

[aussieboater]

Hi Aussie

I got my bearings for my K&B of RON.

A great guy to deal with and will ship fast to Australia.

These bearings are a bit pricey but well worth it.

My motor run heaps different now it's not sucking air

Get yourself a new set and you cant go wrong.

Jason

Jas

How hard are they to change, did you do it yourself jerry gave me some great info on bearing replacement but also made me nervious about doing it myself

Thanks

Brad

 

[Jerry Wyss]

Brad, It's hard to gudge the skill level of people thru a computer screen. I've seen your O/B,

nice polish job, but thats all I know.

I have did it wrong and right (my opinion),, I messed-up a pto housing the first time trying to get

the bottom PTO bearing out.

The helluvit is that when I did all this I didn't know of a model boater within 200 miles, you may

have a similar situation, but I'm not sure of that either.

My first choice for you would be if you know anyone within a reasonable distance that can do this,

take it to him and watch the first time. If not, then me or someone else on this board is gunna have

to talk you thru it.

Alot'a people on this board think I'm friggin' nuts,, so with that in mind, (and they're well being) my best for you would be Rod Geraghty, with his Vast experience with the K&B engine.

Ron Byrd ,"RaceCraft Bearings" would also be a good one to quiz 'bout this,,gather all the info you can

via the internet and guys on here so you know what you up against before your bearings show up.

If you going to remain in this hobby for very long, you going to have to do this operation MANY times,

with (possibly) several different engines.

JW

 

[RaceCraftBearings]

Brad, It's hard to gudge the skill level of people thru a computer screen. I've seen your O/B,

nice polish job, but thats all I know.

I have did it wrong and right (my opinion),, I messed-up a pto housing the first time trying to get

the bottom PTO bearing out.

The helluvit is that when I did all this I didn't know of a model boater within 200 miles, you may

have a similar situation, but I'm not sure of that either.

My first choice for you would be if you know anyone within a reasonable distance that can do this,

take it to him and watch the first time. If not, then me or someone else on this board is gunna have

to talk you thru it.

Alot'a people on this board think I'm friggin' nuts,, so with that in mind, (and they're well being) my best for you would be Rod Geraghty, with his Vast experience with the K&B engine.

Ron Byrd ,"RaceCraft Bearings" would also be a good one to quiz 'bout this,,gather all the info you can

via the internet and guys on here so you know what you up against before your bearings show up.

If you going to remain in this hobby for very long, you going to have to do this operation MANY times,

with (possibly) several different engines.

JW

Jerry the first time I changed bearings was many moons ago and while it came out ok it was an ordeal to say the least. I have become very good at the task over the years with crank bearings. The PTO's even for a pro are a challenge but given the correct tools can be acomplised just as easilty as the crank bearings.

PS you nuts? What ever gave them that impression :huh: ??

Brad, Rod Geraghty has forgotten more about K&B's than 10 of us OB'ers together will ever know!

If I can be of any help please don't hesitate to ask and as Jerry states if you have a fellow boater close who has the ability to do it for you then by all means watch and learn.

Ron

 

[Jerry Wyss]

PS you nuts? What ever gave them that impression :huh: ??

Ron

I can hear "finger nails" being chewed sometimes when I write suff on here, I know I've

raised Rods blood pressure a few times cause I have called him afterwards and asked him

if He thought I was "nut's" and He said "Yeah" :lol: I don't like doin' that to him, I want to

have Him around a bit longer

My main thing is this operation is that I like to try and tap the crank away from the rear

bearing without moving that bearing too. This is JUST so I can get some tools in between there

later to make it easier to get the rear main off'n the crank (can be a problem sometimes).

Then heat the housing up a little and drive the bearing out with the crank.

Similar operation on the PTO, stick an appropriate sized "ball-end driver" in the "squaredrive"

and tap (rap) with another plastic handled tool and try to get some seperation between the pto

plate and "inner" pto bearing, then heat-up and knock both them parts out.

The "outer" pto bearing can be a pain in the butt sometimes, I start by freezing the pto housing

with the rear bearing in it, then heat-up the squaredrive end of the pto shaft and the housing quickly,

stick the pto shaft back in and give'r a rap on the pto plate. Half the time, its enough to move it away

from the housing,,this is the area where I ruined my first pto housing, by grinding a punch and trying

to drive it out (hard to hold all that stuff) The section ( of the pto housing) between the two pto bearings

can't have so much as a scratch on the bore or your in jeopardy of leaking air there.

I made-up an aluminum "inertia" bearing removal tool that bolted up to the outside of the pto base

and has a 1'' hole in it to clear the outer bearing. The aluminum I used was thick 2" wide flat stock

and 14" long,, bolt it all up, heat-up everything at the end and give'r a slap on a wooden cutting board.

The outer bearing will be sitting on the cutting board every time,, unfortunately, I fail to remember where

that tool is and I'm sweating from looking. It's a simple thing, use the outer pto base as a pattern and

slap, Slap your way to victory :lol:

I'm outa here!

 

[aussieboater]

Hi Jerry and Ron

I do know of a guy fairley close to me that will do the bearings for me so i can learn as well like you said Jerry i dont want to ruin any part as parts are hard to come buy again thanks heaps for the info.

Also i have the 8702 motor so ill have to order some soon will let you know Ron ill email you

Thanks

Brad

 

[Jerry Wyss]

Brad, I do have a spare (used) pto with shaft & gasket if sumthin' bad happens.

Found it while looking for the "inertia slapper".

 

[aussieboater]

Awesome thanks Jerry will keep that in mind im also thinking while its apart i might put a new piston and liner in it whats your thoughts compression feels pretty good but i would have to feel a new engine to compare the difference and i know noone close to be able to do that so i thought may as well do it

Thanks

Brad

 

[RaceCraftBearings]

Awesome thanks Jerry will keep that in mind im also thinking while its apart i might put a new piston and liner in it whats your thoughts compression feels pretty good but i would have to feel a new engine to compare the difference and i know noone close to be able to do that so i thought may as well do it

Thanks

Brad

Brad I would run the P/L that you have till the cows come home and save the new one for a rainy day!

Ron

 

[Jerry Wyss]

Awesome thanks Jerry will keep that in mind im also thinking while its apart i might put a new piston and liner in it whats your thoughts compression feels pretty good but i would have to feel a new engine to compare the difference and i know noone close to be able to do that so i thought may as well do it

Thanks

Brad

I Think That Post Was Addressed To Me! Mr. Bearing Head!,,,,,,,,,

Brad,

I'd wait until you get over the "heart attack" from the cost of the bearings

before you look in to that.

It's a good thing your gettin' new bearings in there, Before, the old ones completely

destroy your engine, and destroy it, They Can!

What I would look into, would be the "Keeley" head button, a simple mod that will

really wake'm up and I don't think the cost is all that bad.

Terry is on IW quite allot, give'm a PM

I have alot of servicable parts here that could keep you in buisness for a long time.

They're just sittin' in my cabinet takin' up space,, if you need a part just ask.

JW

 

[aussieboater]

Hi Jerry

Thanks heaps for that ill keep the parts in mind also this Terry is that his user name on here and what does he do to the head button

Thanks

Brad

 

[Jerry Wyss]

Hi Jerry

Thanks heaps for that ill keep the parts in mind also this Terry is that his user name on here and what does he do to the head button

Thanks

Brad

"Terry Keeley", I hope I spelled his last name correctly :blink: only have seen it 100 times.

There is alot of power to be had with a well structured headbutton, I'm finding that out with the

Thunder Tiger O/B. Many marine motors provide you with a volume that "TRY" to cover a wide

range of nitro fuel usage,, normally coming up short on one end of the spectrum or the other.

I have only "heard" that the Keeley button "really wakes them up" and have also heard an

interesting story "of how" he came upon the buttons in the first place. I don't know if "that

story" is true or not so I won't gossip here,, ok, I put on the Big spinner, lets see what we

catch h34r:

 

[aussieboater]

Hi Jerry

I will try find him on here and see what he says also i have just brought gmortys (Greg) TS2 and it has a thunder tiger on it interesting to here more on that little motor as well , what have you done to yours is it piped and so on

Thanks

Brad

 

[Jerry Wyss]

Hi Jerry

I will try find him on here and see what he says also i have just brought gmortys (Greg) TS2 and it has a thunder tiger on it interesting to here more on that little motor as well , what have you done to yours is it piped and so on

Thanks

Brad

Aw gawd,,,yes,,, "piped and so on",, ya know, you grind, cut, manufacture new parts and try to

turn a Rock into a Diamond for a long time and at some point you turn around and notice that

the original manufacturers Haven't done a **** thing in improving they're product!

O.S. , Thunder Tiger , K&B , NovaRossi , Rossi , Mac,,, Take a good Look gentlemen,, What do You see

Look's to me that the patient is dying on the table in the O/B area.

With that aside, Put a pipe on that TT as fast as you can. It's a TD prepared TT (I believe) so it already

has several things done to it. Ofna and Dynamite car headers work best, pipes, SPP is in your neck of

the woods so go for that. I just cut out a lower for another IW boater so I'll take pics to guide you.

As for the TS2, I guess you can look forward to joining the line's over in O/B forum.

 

[aussieboater]

Jerry,

Thanks Mate show me these pics not in a desperate hurry to pipe it but in the near distant future i will yeah (love to tinker)

Thanks

Brad