Rotax 300 builld

[RManson]

Rotax Lamby build-108 by PotvinV8, on Flickr

Rotax Lamby build-109 by PotvinV8, on Flickr

A few more hours machining and we'll be right back where we were except without a kickstarter. lol

[TED CRUD]

RManson well done I

[dapper]

My Nammer had electric start on it when I first got it. I still have the flywheel with the ring gear on it and the starter motor. The mag housing had a gert lump of ally welded on it to support the stater motor. Unfortunately, the mag housing is fecked where the seals go, and the flywheel is a points flywheel with brass centre

[RManson]

Finally got a chance to hit the shop and actually made some progress!

Rotax Lamby build-110 by PotvinV8, on Flickr

Knocked out a couple Oilite bushings to support the starter Bendix and welded the engine side support plate to the mag housing. Also finally dropped both crank bearings in place. Typically not a point of mention, but I was a bit concerned that the crank centerline actually still matched the engine case centerline once everything was all said and done. Turned out it was all within a few thou. Good news and that means we can press on with the starter setup....

Rotax Lamby build-111 by PotvinV8, on Flickr

[RManson]

This is where things got tricky and went a bit pear shaped. I bought a Bendix for some sort of Aprilia Rotax go-cart motor on a lark that it would mate with the RS125 ring gear that came with my flywheel. Turns out it's a perfect match. Touch! Only problem is I couldn't figure out how to drive it properly as it operated in the opposite rotation than required. A quick inspection and I had the Bendix apart, flipped around, TIG welded back together and made it rotate the way I needed it to. This opened up the possibility of actually mounting the starter assembly as it wouldn't have worked the other way. I should mention that I relocated the ring gear from the backside of the flywheel to the front to make this all work. You didn't think it'd be easy did ya?!

Rotax Lamby build-112 by PotvinV8, on Flickr

Though it looks like the flywheel/Bendix gears are meshing, the Bendix gear is actually behind the flywheel gear and "jumps" forward to engage the flywheel gear when the larger, fine tooth gear is engaged by the starter. This prevents the flywheel/starter/Bendix from spinning when the engine fires, but you knew all that, right?!

Rotax Lamby build-113 by PotvinV8, on Flickr

[RManson]

Next, it was time to figure out how to support the Bendix as well as fabricate a housing of sorts that the starter will be able to mount to.

Rotax Lamby build-114 by PotvinV8, on Flickr

You can see the Oilite bushing poking through that supports the Bendix. I had to play with the height of both bushings to get the alignment right between the Bendix and the flywheel ring gear. The pocket for the starter nose cone has also been machined as has the first mounting point.

[RManson]

Next, I used the aforementioned cover and attached it to the new mag housing/cover thingy (with bolts this time!). You can see that the machining for the starter is complete.

Rotax Lamby build-115 by PotvinV8, on Flickr

Which only means one thing, we can bolt on the starter!

Rotax Lamby build-116 by PotvinV8, on Flickr

Rotax Lamby build-117 by PotvinV8, on Flickr

[RManson]

Of course this is all boring and pointless without video...

Rotax Lamby build-118 by PotvinV8, on Flickr

Getting close to firing the motor up, but so much more still to do. Stay tuned!

[Toddy]

Of course this is all boring and pointless without video...

http://vid1177.photobucket.com/albums/x ... m3stjb.mp4[/photobuckvid]

Getting close to firing the motor up, but so much more still to do. Stay tuned!

Great little video , great thread as well some excellent work gone into this project looking forward to seeing it running

[ArmandTanzarian]

Brilliant.