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2stroke Flywheel ring gear

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In the course of my winter teardown I discovered the ring gear starting to walk off the flywheel of my '13 250RR.  I pressed it back square no problem, and will have it tac welded Friday.  We utilize a lot of precision Tig on high vacuum systems, but I'd like to see how the factory welds are positioned, their size, and how many there are on the newer flywheels.  The magnets are bonded to the inside of steel flywheel so my concern is heat.  A pic will help give me a good idea of what the welder needs to do and no more.  Thanks.

That said the rest of the lower end is flawless @ about 400 hrs!  Rod axial play is .43mm (spec is .39 to .72),  bearing looks good, nice thick coating of red Dominator on the crank.  Top end very clean @ over 100 hrs.  Good stuff, sticking to my formula and running it again this year with a new top end and reeds.

Edited by GP
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Pretty darn good for a 6 year old bike! A testament to Beta's solid platform and durability. 

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Couple pics in this old post. Hopefully they are good enough. 

 

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Looking at the engine service manual (pg 21 and 98) that Beta has up on the Betausa.com/support page, there looks to be 4 welds, each about 1-1/2" long. The pictures only show the outer face of the flywheel, but you can see the evidence on the metal.

@Bassman had a similar issue with his 13 and made a repair - maybe he can chime in.

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I have zero welding skills. I am not even good at tack welds, but I just hit the wheel in 4 spots with a harbor freight wire welder and there has been no movement since. The heat should not be an issue. Each tack is about a second. I still have the new fly wheel, I can take a pic of it when I get home. They had even less than mine. I posted a pic somewhere on here when I did it.

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Found them. The first pic is my unhandy work, the 2nd is the updated stock flywheel. tapatalk_1547654518682.jpegtapatalk_1547654537332.jpeg

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That's perfect Bassman, thanks.  It gives me an idea of how much heat is acceptable.  I'm a decent stick welder and have my own machine, but I'd rather have this done Tig by a pro. 

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They also have 4 equal spots but it is very minimal. I did clean my spots up before reassembly.

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3 hours ago, firffighter said:

Pretty darn good for a 6 year old bike! A testament to Beta's solid platform and durability. 

Yeah, besides the Zokes its been great considering the use.  I credit the motor to a lot of oil and precision assembly, its always been very low vibe bike.  The Force guard and link guard on the other hand need some work.😮

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When did they start tack welding the gears at the factory? tbh, other than installing a rekluse, I haven't taken off a single cover on my 14 motor. I keep telling myself that I should at least inspect and service the starter. But the thing still runs like a top.

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1 hour ago, GP said:

Yeah, besides the Zokes its been great considering the use.  I credit the motor to a lot of oil and precision assembly, its always been very low vibe bike.  The Force guard and link guard on the other hand need some work.😮

It's funny. One of my concerns with going with the 300 kit was more vibes (my wife's Xtrainer was vibey), but your 300 piston in my bike vibrates less than my bike did with the 250 piston. 

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1 hour ago, randysoo said:

When did they start tack welding the gears at the factory? tbh, other than installing a rekluse, I haven't taken off a single cover on my 14 motor. I keep telling myself that I should at least inspect and service the starter. But the thing still runs like a top.

I pull the motor, its easier to work on it on the bench, and gives the opportunity to clean up and check the frame good, and the starter as well.  I pulled the starter apart a couple times, last year put in new brushes.  It sits low, often in wet crap in the skid plate, so doesn't hurt to check the integrity.  There is only a very thin rubber seal between the halves keeping water out of the motor.  I know of a couple that leaked and failed in a couple years.  

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