NR 46 Outboard Bearing Questions

[RonShaw]

Is anyone else experiencing front bearing issues with the NR 46? A front bearing failure cost me a first place finish in my second heat and almost took out Culhane that was right behind me. I parked it for the rest of the weekend with no time to change bearings, so it may have ended up costing me a top three finish. This was only the third race with very little run time between the races. Using proper engine maintenance and cleaning, I am used to only switching out the bearings no more than once a year. I know K&B had 45 OB front bearing issues until they added a reverse spiral groove leading from the top corner of the intake opening on the crank, all the way to the front bearing. This helped pull lubrication vertically to that bearing. Maybe drilling a hole in the housing to allow lubrication of that bearing in between heats will help, (another practice by K&B ). I am hoping to get some feedback from anyone else running these motors.

Also, I am thinking ceramic may be a fix here. Does anyone have the exact measurements of the front, rear, and PTO bearings? I will check with Boca to see what they have available. Thanks.

 

[moparbarn]

ron, check with jon/tnrcboatracer here. excellent bearings at a reasonable cost. great service & a good guy to know .

 

[James E Beasley]

I bought my Inboard NR 46 used from Joe Warren I think it was, and he said he put 3 runs on it, I have put 8 runs on it, and have properly lubed it after reach session. At the Fall Nats while running in my PT S40 the throttle barrel stop screw broke off like others have reported but I got lucky and Doc Turner blew over right in front of me and I crashed out. When I inspected the boat I discovered the barrel hanging out of the carb. Once back in the pits I tore the carb apart and found the carb spring luckily still in the carb. Still concerend about the missing part of the stop screw I tore the engine down completely and found it had not eaten the screw nipple, but discovered the bearings and PTO face were rusted beyond belief. The bearings and othe r steel parts in these engines are not made of the quality material that NR is know for. The head bolts are also rusted terribly, even the bolt heads. Inside of the cooling jacket was a rust mess. I am very dissapointed. This is not what we expect from a $500 NR engine.

 

[RonShaw]

If someone can help with suggestions on the bearing issues and sizes, that would be great. Looks like James is having issues as well.

 

[Mike Betke]

We are running the Nova 46 inboard in our outrigger. I went thru a set of bearings quickly and I thought it was due to the after run oil that I was using which was some older turbine oil. Since then we have about 4 races on a new set of bearings and they are sounding a little suspect. I completely tear the motor down after every race or test session and lube the bearings good so it is not a maintenance issue. It is looking like these bearings may be very delicate. The bearings that they use have many smaller balls in them. I prefer bearings to have less balls that are bigger in diameter. I am not totally convinced yet that it is a major issue, but Nova should be looking at it as a potential problem.

I am pretty sure that these bearings are a custom made bearing by Nova, so I do not think there are any aftermarket options. Be careful installing new bearings. If the outboard crank is similar to the inboard it is not easy to install the front bearing. We had to make an installation tool to get it in straight. Glenn sells tools for installing the bearings that make it easy a well.

 

[RonShaw]

Thanks Greg. Thats what I am thinking as well. Do you know the sizes of the bearings in a 46? I am thinking ceramic might be a better choice so I wanted to see what aftermarket bearings may be available.

Thanks for your feedback too Mike.

 

[Glenn Quarles]

I too have some of the original motors with the original bearings and zero rust. The metal in these motor is the best material available and is is the same as Nova has always used! Nova's quality is exactly the same as it has always been, and I would venture to say it is the best of any motor available.

I can't comment on the 46 OB bearings as I don't run one. Since this is the first time I have heard of this problem out of all of the 46 OB motors I have sold I am not going to make it a big deal for Nova to work on. If the problem is more wide spread than I know of, I will be happy to see if they can do something about it. Please keep me in the loop!

In general if bearings are going bad from running, it is a fuel lube issue, if there is rust in the motor then it is an after run issue.

I will talk to Nova about different bearings with bigger balls.

GQ

 

[dion smith]

Ron, I got Greg Settle to go over my bearings, might be worth a shot

 

[RonShaw]

Thanks Glenn. I believe this will be mainly an outboard issue. Getting lubrication during use to that top bearing has always been an issue with outboards. Let's see if others are having this issue with their top bearings as well before you run it up the flagpole at Novarossi. I posted earlier how K&B solved the issue. Maybe Novarossi can look at this as well. The power from these motors is over the top, but if we are not finishing races, we need to solve the problem. Do you have ceramic bearings available for the 46 OB? Do you know the sizes of the bearings?

 

[RonShaw]

Ron, I got Greg Settle to go over my bearings, might be worth a shot

Thanks Dion. Mark Sholand mentioned him as well. If he doesn't chime in I will send him a PM and get his input too. Does anyone know the sizes of these bearings?

 

[RonShaw]

Thanks Greg. Let me know what you find out... BTW, did you order one of the new THOR's from Carl? Better get on the list!!

Glenn,

I found the ceramic numbers on the NR website.

17452- Ceramic Front Bearing

16371- Ceramic Rear Bearing

Can you PM pricing and availabilty for two each of these ceramic bearings and for two each of the new 46 cooling jacket and reduced volume turbo head button? Thanks.

 

[moparbarn]

greg, ron does the same as you & i do. runs it on the bench with oil & methanol. he said 20% oil ( if i remember correctly?). i suggested 30%, which is the ratio i use. i don't believe it's a maintaince/after run issue, he runs it for quite a few minutes. i've watched him do it. not sure what type of oil he uses, i use byron's, 95% synthetic/5% castor with great results.

ron, i don't run .45's, but the spiral groove on a .21 k&b crank actually spirals oil back down away from the front bearing, not up to it.

 

[RonShaw]

I use 30% oil and methanol, brew recommended by Kentley. My maintenance isn't the issue. The spiral on a K&B 45 9702 is reverse to carry oil vertically up to the front bearing when running, which would help this motor. An oil hole at the top for a shot of lube before every run will help. Just looking for feedback from other NR 46 outboard owners and if they are having issues with this bearing as well, so NR can address the factory if it is a universal problem.

 

[moparbarn]

we were talking while your engine was being after run, so i misunderstood you due to the noise. that, & 40+ years of noisy engines at work & the pond .

so the .45 k&b crank spirals opposite from the .21. i learned something .

 

[RonShaw]

No problem Robin. I used to use 25% which may have been what I was using then, but Kentley recommended 30% a while back. Heck, until I saw what he was doing at the SAW Events, I never thought about using this technique, but it works extremely well. Follow-up with Marvel Mystery mixed with Auto Transmission oil with Dextron, and you are good to go until the next run. If we started a topic about after-run techniques, we would probably start a 500 response thread!!!...... :blink:

Yes, the 45 has a spiral groove that turns opposite from the crank direction to help carry oil up to the front bearing while running. I think the Pro engine has it as well as the 9702's.

 

[RonShaw]

I too have some of the original motors with the original bearings and zero rust. The metal in these motor is the best material available and is is the same as Nova has always used! Nova's quality is exactly the same as it has always been, and I would venture to say it is the best of any motor available.

I can't comment on the 46 OB bearings as I don't run one. Since this is the first time I have heard of this problem out of all of the 46 OB motors I have sold I am not going to make it a big deal for Nova to work on. If the problem is more wide spread than I know of, I will be happy to see if they can do something about it. Please keep me in the loop!

In general if bearings are going bad from running, it is a fuel lube issue, if there is rust in the motor then it is an after run issue.

I will talk to Nova about different bearings with bigger balls.

GQ

Glenn,

I found the ceramic numbers on the NR website.

17452- Ceramic Front Bearing

16371- Ceramic Rear Bearing

Can you PM pricing and availabilty for two each of these ceramic bearings and for two each of the new 46 cooling jacket and reduced volume turbo head button? Thanks.

 

[RonShaw]

Glenn has ordered the ceramic bearings for my 46. I will also make sure I oil the top bearing before each heat. Hopefully this will take care of my problem. Thanks.

 

[rumrunner]

Ron will he have all the replacement bearings in ceramic even pto?

 

[Glenn Quarles]

Ron will he have all the replacement bearings in ceramic even pto?

Shane, I don't think Nova offers ceramic bearings for the PTO, would you like for me to ask them if they will make them?

GQ

 

[RonShaw]

Ceramic PTO bearings as well would be great if NR can accommodate the request Glenn.