RR 300 engine rebuild questions

[ged93]

Hi everybody , I'm rebuiding my Tm 300 engine and it's a real pain , luckly I can turn around and take a look to my beautiful Beta , and I was thinking about some questions regarding RR engine rebuild ( bike is new , so I'm just curious ) : 

- RR engine splitting : how is it hard to do ? For my Tm I need a special tool ( which is pretty normal ) and heat , a lot of heat ... but what about Beta ? Does it need heat ? I'm asking because I would like to know if I can re-split the engine easily if I realize that gear box is not working well ( re-splitting on my Tm is a suicide ... )

- Crank shaft : in order to push crank shaft into its bearings , is it necessary to use heat ? 

- Selector drum shaft bearings : what about the positioning of this shaft bearings ? I'm talking expecially about the one on clutch side : is there a shoulder machined inside this bearing hole ? On my Tm that hole is machined completely through the case and without a bearing shoulder so you cannot find the correct bearing position , so you need to try again and again 

- Crank shaft seals : are them hard to push in ?

- Other things on RR 300 engine rebuild ?

RR 300 engine mechanical solutions looks great from drawings , but I would like to have some responses from those who already had rebuilded one .

Thanks 

 

[motoxgiant]

Very straightforward. Do not be afraid, especially since it won't need a rebuild for about 400 hours ?

[silver_fox]

Very simple. I needed a special puller to split the case but the rest was very easy, just follow the instructions provided in the manual (download from Beta site). I had a rare crank bearing failure (caused by rust) at 50 hrs on my '16 300rr.  

[mtdirtbag]

5 minutes ago, silver_fox said:

Very simple. I needed a special puller to split the case but the rest was very easy, just follow the instructions provided in the manual (download from Beta site). I had a rare crank bearing failure (caused by rust) at 50 hrs on my '16 300rr.  

Did you happen to use Redline pre-mix 2T oil?

[silver_fox]

1 minute ago, mtdirtbag said:

Did you happen to use Redline pre-mix 2T oil?

nope

 

[ged93]

9 hours ago, motoxgiant said:

Very straightforward. Do not be afraid, especially since it won't need a rebuild for about 400 hours ?

Yes I know ,  I'm just curious ... so it's not necessary to use heat to split the engine and assemble crank shaft into bearings ? 

[silver_fox]

1 hour ago, ged93 said:

Yes I know ,  I'm just curious ... so it's not necessary to use heat to split the engine and assemble crank shaft into bearings ? 

Correct

 

[OMEGAENDURO]

After having just rebuilt my 250 (with help, first time) I was impressed with not only how straightforward the process was, but how thorough and accurate the service manual was. Take your time, take pictures and have the correct tools and I think it is do able for the "weekend" mechanic. 

[ged93]

At page 54 of RR 2s service manual , talking about engine re-assembling , I 've found this : 

' By heating the bearing it will be possible to move 
it close to the right crankcase half by hand '

but I don't understand what does it mean , so it's necessary heat to close cases ?

Thanks for your help

[GP]

Always use heat /cold to shrink fit parts when possible and avoid as much force as possible.  NEVER press or worse hammer across the races of a new bearing, its junk then.  Heat the cases in the oven, on a wood/pellet stove (I do rebuilds in winter) or your gas grill, watching the temp.  bearings should just tap out.  Dry ice is your friend and available, freeze the bearings while the case is heating and they will just about drop in.  If the heat from the case doesn't drive off the condensation from the bearing, return it to the heat source so it does.  Same with the crank assy in the right side bearing/case, freeze it, and warm the case.  Ignition side and countershafts are usually not hard, but if  tight, take a toilet paper cardboard tube, place it over the shaft, and pack it with crushed dry ice.   I have access to liquid nitrogen to freeze parts and it makes the job so easy its ridiculous.  In general use your head, not the hammer, and you will stay out of trouble.?

[ged93]

2 hours ago, GP said:

Always use heat /cold to shrink fit parts when possible and avoid as much force as possible.  NEVER press or worse hammer across the races of a new bearing, its junk then.  Heat the cases in the oven, on a wood/pellet stove (I do rebuilds in winter) or your gas grill, watching the temp.  bearings should just tap out.  Dry ice is your friend and available, freeze the bearings while the case is heating and they will just about drop in.  If the heat from the case doesn't drive off the condensation from the bearing, return it to the heat source so it does.  Same with the crank assy in the right side bearing/case, freeze it, and warm the case.  Ignition side and countershafts are usually not hard, but if  tight, take a toilet paper cardboard tube, place it over the shaft, and pack it with crushed dry ice.   I have access to liquid nitrogen to freeze parts and it makes the job so easy its ridiculous.  In general use your head, not the hammer, and you will stay out of trouble.?

Hi , yes thanks I knew the trick of heat/cold for bearings and in general for machined and high precision components .

I work with bearings , precision components and industrial machines , so it's clear for me to don't use hammer or press , oviusly - I was curious about splitting and expecially a bit scared about re-assembling between crank shaft and ignition case , but it seems easy now .

I have access to nitrogen too , how much time do you get to freeze the crank ? 20-30 seconds for each side ? Do you freeze also 1st and 2nd gearbox shafts before pushing cases together ?

[GP]

1 minute ago, ged93 said:

Hi , yes thanks I knew the trick of heat/cold for bearings and in general for machined and high precision components .

I work with bearings , precision components and industrial machines , so it's clear for me to don't use hammer or press , oviusly - I was curious about splitting and expecially a bit scared about re-assembling between crank shaft and ignition case , but it seems easy now .

I have access to nitrogen too , how much time do you get to freeze the crank ? 20-30 seconds for each side ? Do you freeze also 1st and 2nd gearbox shafts before pushing cases together ?

I have done a quite a few motors and only one GG had a tight crank in the ignition side bearing that gave me trouble, but GGs of the time were known for crappy tolerances.  Generally just warming the side case assembly will allow it to go on fairly easy with some light taps of a plastic mallet, and cranks usually drop in warm bearings.   On said GG job I had LN2, I taped up a cardboard tube on the crank and poured LN2 in for a minute or so.  As you know if experienced with LN2 it will continue to boil away rapidly as you will never equalize that mass without submerging it.  For that reason dry ice is  better for this as it lasts a lot longer in contact even though not as cold, so the end net result is a colder part.  For bearings to be fitted to cases I drop them in a dewar and they equalize in seconds.

Another great LN2 trick.  Need to remove a lower steering stem bearing?  Plug the bottom of the stem with a small cork or stopper.  Fill and keep topping off the hollow stem for a couple minutes.  Invert and tap the top of the stem sharply on the bench, the bearing usually will fall right off.