Hi All,

 

Beta 2008 2T 250 Rev-3

 

The time has come to do my main bearings. Is it just a case of swapping the mains or should I be thinking of doing any others while I'm in there? I'll obviously be checking the big end but are there any in the grearbox I should be changing?

 

I've made a list of all the bearings and seals from the parts diagrams:

 

Bearings

 

6206 2RS?             Shielded. unsealed               x2

10x22x6                                                               x2

15x28x2                Needle bearing

12x18x12              Needle bearing                       x2

25x37x7                Ball bearing

30x37x12              Needle bearing

20 52 15?             Italian Measurement?             x2

16x21x10 2pcs     Needle bearing                       x2

15X35X11             Ball bearing

18x22x10              2piece bearing                       x3

18x22x10              1piece bearing                       x2

15X35X11             Ball bearing

16x20x10              Needle bearing

 

Seals

 

Oil seal 12x22x5

Oil seal 20x37x7

Oil seal 16x22x4

Oil seal d014 9 tc 25 40 7 ttc                        x2

 

Thanks

 

 

Nice one. I dont have access to a heat gun so was going to put the case in the oven @250 and then tap it out.

 

Did you put all new gaskets in or reuse the old ones?

 

 

 

Nice one. I dont have access to a heat gun so was going to put the case in the oven @250 and then tap it out.

 

The oven should work fine. It's more controllable than the heat gun (you know exactly what temperature you're giving it) but inevitably the bearing will be as hot as the case. Do the same when you come to put the new bearing in, but then you have a hot case and cold bearing so it should go in easier. (These jobs are best done when the female of the family is not in the house. )

 

Hello again.

I managed to get the bearings out nice and easy after heating them up to 250 and tapping them out. I've just been out and got new gearbox and main bearings.

Couple of questions before I start putting it all back together, just to make sure I do it correctly. (You can take that with a pinch of salt as I imagine some of you would be cringing and rolling your eyes at some of my "techniques".)

The main bearings I got had metal seals on them. Which I have taken out. Thinking about it should I have even taken them out in the first place? When I phoned beta I'm sure he said they had to be 2 rs which is rubber sealed.

When assembling everything do I just use neat 2 stroke oil to coat everything in the crankcase and gear oil for everything in the gearbox? Do I need to soak my clutch plates again?

When I join my crankcases do I need a thin smear of sealant or is the paper gasketalone sufficient?


I'll be back with more questions I'm sure but for now that should keep me going

Edited November 14, 20169 yr by itzuki

Bearings are in. Oven and freezer FTW.

 

Quick question. Before I put the bearings in the freezer I washed the grease out that was behind the seal. Was that the right thing to do or do I need to re apply a thin layer or is the 2 stroke enough to keep them happy?

 

I've just been looking at the cases. All fresh and renewed and got to thinking. Is it just a better idea to get my big end sorted while its apart? I've called a trials bike dealer and they said they don't have a press to do the big end. Is there anywhere anyone knows in Yorkshire who could?

 

Thanks

Edited November 15, 20169 yr by itzuki

What about if its the tiniest bit? I don't know whether I'm shifting it sideways when i try pull it though?

 

Yes, there are oil feed tubes the go to the outside of the bearing from under the cylinder. I got 2Z C3 bearings.

 

Edited November 15, 20169 yr by itzuki

Will do. I was thinking the same.

 

I think the con rod for mine is 200 and then 40 for the actual work to be done. I'll just put it back together and see how it goes. I need the crank seals to come in the post and I can get on with putting it back together.

 

Thanks again

Un-shielded came out so sod it I'm going un-shielded. Didn't want all the grease to just come flying out in my nice clean engine. I'll see how it goes. The next rebuild will be 10 times easier now I know what I'm doing

Yep filter is oiled and in good nick.

 

I did think about leaving them in but decided against it when I saw the channel going to the outside of the bearing. If I were to keep them in could that channel have filled with oil with it being sealed by the end of the crank and the metal seals?

Aye. If the ones I took out are original they've been in for 8 years! They looked 8 years old.

Edited November 16, 20169 yr by itzuki

Hi again,

I've got everything back together. The only thing is the crank seems rather tight. I think I may have tightened the clutch basket up too tight. Does anyone know what torque to put on it? I'm imagining it isn't that tight seeing as it's got the locking tabs on it.

Also. Are the crankcase seals lubricated from the inside? My friend started the build and forgot to lube them when he put them on.

Ay Up,

 

Thanks again for helping me out oni.

 

I went to where the engine is after work (it's been playing on my mind all day.) I stripped the engine back so I could get to the seals and got the smallest feeler gauge I could and managed to get some two stroke oil in behind the seal. This made the crank easy to spin. I think there is a bit of grease still in the bearings so the rod isn't free-falling back into the cylinder yet. I gave the ends a tap with the nylon hammer too while I was there. I built up the clutch side and there was no change while I was doing so. I attached the flywheel and did it up finger tight and that is when it became hard to turn. I think I've got the heavier flywheel as it's got some weight to it. Does the flywheel have magnets in it? Could this be why its becoming harder to turn?

All back together again. Kicking over nicely. I must be getting weak in my old age. I didn't manage to actually start it as it was too late but it feels 100 times nicer to kick. I downloaded the manual you recommended too and it helped a lot.

Thanks again for all the replies. I couldn't have done it without you.

What sort of mix should I run for the first few outings?

Good to hear you managed to get through it ,80:1 is ok.Enjoy your riding.Regards.

 

After encountering "Spooge" I realised I had lost the needle jet!

 

I bought a new one from Allens Performance - http://www.allensperformance.co.uk/ £10.16 including next day delivery! Is there a post where they keep details of suppliers of parts? I think they would be worthy of an add.

 

I went out on it today to have a test and found out I'd forgotten to plug the fan in in my haste to get it back together. I sorted that tonight and other than that all seems well. Other than the little bit of clutch rattle but I think it's just the plates wearing I checked all the bolts tonight and they were all tight. How long should a clutch last on average with mainly low revs?

 

We're going to Cowm at the weekend to give it a proper test so will report back then,

 

Thanks again for all your help.I really couldn't have done it without you all.