OS Outboard Interesting bearing issue.

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David Santistevan

Well-Known Member
Joined
Aug 5, 2011
Messages
1,365
So I had one of trusty OS engines that I have rebuilt and run for many years do something really odd. Earlier in the season when I rebuilt it for the year with all new bearings and piston and sleeve, I had it lock up at the second race I went to. It acted like the piston and sleeve were too tight. I managed with a little for with my hands to finally get it to turn and it has run fine occasionally locking up. I seemed to always forget before the next race to tear down the motor and see what was going on but this weekend it got worse and the boat actually starting dying. Here is what I found. This is one inside PTO bearing!


Luckily this was on the unsealed side of the bearing that faces the other bearing and the PTO shaft so none of the entered the crankcase.

D
 
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Better than inside the engine!
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Wow thats a first, never saw that one before...Glad it did not damage your engine.
 
Dave, I may be wrong, but i think you can run an after market bearing in the stock class. ceramic bearing no. steel balls should be o.k.
 
John, that would be big news for me. I just re-read the rule and it seems like aftermarket bearings would definitely be a no no. Does anyone have a solid answer on this?

D
 
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John, that would be big news for me. I just re-read the rule and it seems like aftermarket bearings would definitely be a no no. Does anyone have a solid answer on this?

D
My understanding of the NAMBA Stock Outboard "Engine Specifications #F" would allow the use of after market bearings if such items were available through normal outlets - i.e. Boca Bearings.

I'm not the NAMBA Outboard Chair, but I've raced Stock Outboard for a little while.
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JD
 
Isn`t that an aftermarket product anyway? I mean OS does not make the bearings them self, it is supplied by a third party. Or does the rules say that parts need to be provided in an OS labeled bag/pack?
 
IMPBA allows as internal changes not noticable from outside the powerhead are ok. As the OB Chairman for several years, NAMBA, per the current rules, does not allow, as their rules are much more strict than IMPBA. OS recently changed the OB part number on the rod to include the wrist pin clips on the last stocking order I received from them. Since the number is different than what shows on the parts listing, I requested a letter from OS for my records as an official factory change to the OS 21 OB just in case there was ever a question about the part number change from any customers. I really hope the two organizations will come together on the rules one day for better consistency in this class.
 
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OK, well you have two of the most respected outboard racers on different sides of this fence. I would love to be able to buy these bearings from Boca as they are a fraction of the price. On the other hand I never want to be called in the case of an engine tear down. Maybe Jimmy Johnson or Al Waters can throw their two cents here! Does anyone have the Boca part numbers for these bearings?
 
The biggest problem i have with a stock bearing from O.S. is they will put a steel cage zz bearing in there engine that may cost them one dollar and last all of two races.

Good luck

John
 
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I do not believe you can change the bearing from the original manufacturer, this being OS in this case.

Does not give any leeway to use another bearing manufacturer. Of course I have been wrong before.

NAMBA Rulebook

19.C.2.e

  1. [SIZE=12pt]For the stock classes, the engine’s parts must remain as originally manufactured for that brand, size, and style engine. No modifications are permitted. Interchanging of parts from one series or edition to another is legal as long as the parts used were made by the manufacturer of the engine and were used on their outboard engines.[/SIZE]
 
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never had an issue with OS bearings myself...yeah the price is dearer, but how often do you change them?

On another note, they are ALOT dearer now than previously...OS is certainly heading upwards in price
 
I do not believe you can change the bearing from the original manufacturer, this being OS in this case.

Does not give any leeway to use another bearing manufacturer. Of course I have been wrong before.

In my #8 post, I interpreted the rule the way I'd like to see things. But, obviously I was blind to what the rule actually states. In all the years I've run O.S. OB's I've never changed the bearings in the PTO. Not saying that maybe they should be changed, just that I've never changed PTO bearings. However, I've replaced the bearings in the engine.

JD

NAMBA Rulebook

19.C.2.e

  1. [SIZE=12pt]For the stock classes, the engine’s parts must remain as originally manufactured for that brand, size, and style engine. No modifications are permitted. Interchanging of parts from one series or edition to another is legal as long as the parts used were made by the manufacturer of the engine and were used on their outboard engines.[/SIZE]
 
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As the NAMBA Outboard Director I cannot make a ruling or give a "FINAL JUDGEMENT" on a specific rule. I can only promote outboard racing within NAMBA, and give my opinion and make recommendations. The rule does specifically state that you must used OEM parts... But in my opinion , a "LIKE FOR LIKE" replacement should be legal. I agree with Ron about the "standardization" of the rules package.
 
I've had several engine tear downs at NAMBA Nationals. I can't remember anyone being very interested in the bearings. I, for one, always replaced my engine bearings with after market brands. I think people have even run hybrid ceramic bearings in the stock classes, but I'm not sure. However, heaven help you if you run a third channel needle in place of the stock one.

Lohring Miller

PS From one proven cheater to another, don't have Rod Geraghty "blue print" your stock motor either.
 
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I agree Lohring. Every time my stuff was inspected, no inspector told me to pull the bearings out, he just looked in to see if I was running ceramics... I've known a couple racers that have run ceramics in stock. As long as you run the original needle, you can run a third channel needle in front of it.
 
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I agree Lohring. Every time my stuff was inspected, no inspector told me to pull the bearings out, he just looked in to see if I was running ceramics... I've known a couple racers that have run ceramics in stock. As long as you run the original needle, you can run a third channel needle in front of it.
The IMPBA 3.5cc 2-lap sport record is held with a box stock O/S engine and was making about 58+ mph at the end of the straights. That engine had the original O/S bearings in it and was also water cooled. I have had a ceramic bearing trash a great engine. I don't run them in the O/S engines at all. I am just pointing out that the fastest engines we have ever had were loaded with steel bearings.
 
In the end I was not asking to gain any performance advantage for sure. I was looking to 1) Reduce the cost of the bearings as OS is pretty proud of them and 2) To replace bearings with a steel retainer with a bearing that uses poly retainer. In either case as long as the rule is understood and everyone is playing by the same rules, it's all good. Another questions that has come to light here is that Jimmy as the class chairman said be cannot make a ruling, so who can?

Thanks Jimmy for your input.

D
 
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