Rotax carbs

Greg Vos

Active Member
Joined
May 26, 2019
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753
Location
Cape Town
Aircraft
R44/22 H269/300 MD 500 Magni (all); Xenon RST; DTA; ELA; MTO Trojan
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Stoped counting at 2000
Can anyone share some info on the bing carbs we find on the rotax 912/ 914 series
A mate at our local airfield is of the opinion they are very similar internally to the bing carbs he works on that are fitted to some BMW motorcycles, we are looking at a carb overall and the cost if we purchase the carb kit from a rotax agent is more than 10 times the price he has quoted to rebuild our carbs using gaskets and other bits from his stock.
we have confirmed our floats are fine and weigh the correct weight, I just want to get opinion because if this is so then it’s a great saving, in discussions with a mate who owns a gyro we are unsure because I’m certain if this was the case then it would be out on the forums?

any advise / comments welcome
 
Many attached items on a Rotax engine are sourced elsewhere, ie not Rotax and exactly the same item with the same OEM (Original Equipment Manufacturer) number can/will be much cheaper. On another UK based flexwing forum microlightforum.com there was a data base of items, carbs included, that could be sourced elsewhere at a fraction of the price.

OEM numbers are created for an item when manufactured, the items are then sourced by, for example Rotax and BMW and are given another number unique to each. Search using the Rotax or BMW number and one will always find only the item relevant to that re-seller. Search the OEM number and one may find multiple sources.

Much cheaper but the same issue, check the price of a radiator cap for a Rotax 582 blue top and the cost of a cap for a Triumph Bonneville, guess which is the most expensive.

p.s. microlightforum.com seems to be experiencing problems at the moment but should be back up and running soon.
 
Seem to remember hearing something to this effect about the turbo’s on our Cessna 402’s when they were being ruined by pilots not allowing them to cool down properly before shutting down the engines. Seems they were identical to ones being used on Caterpillar heavy dozers but very much more expensive.

Will using these items invalidate insurance, even though they are seemingly identical items except for the part No's ?

One might imagine Rotax would attempt to prevent this happening.
 
Gaskets and diaphragms etc are the same, needles and jets are different to bmw.
The 914's float bowl is bolted on so an o-ring is needed in addition to the gasket.

wolfy
 
Gaskets and diaphragms etc are the same, needles and jets are different to bmw.
The 914's float bowl is bolted on so an o-ring is needed in addition to the gasket.

wolfy
914 the float bowl is held in place with a clip underneath ? It’s sort of cams over and clicks in place ? Or have I got a lemon ?
 
That is the case for the 912's but all the 914's I have seen the bowl bolts on. Maybe yours is a real early one?

wolfy
 
I'm tired of Rotax / Bing carbs. Two sets of (expensive) floats, needle valve sticking, balancing. Changing to Edge Performance EFI.
 
Seem to remember hearing something to this effect about the turbo’s on our Cessna 402’s when they were being ruined by pilots not allowing them to cool down properly before shutting down the engines. Seems they were identical to ones being used on Caterpillar heavy dozers but very much more expensive.

Will using these items invalidate insurance, even though they are seemingly identical items except for the part No's ?

One might imagine Rotax would attempt to prevent this happening.
Only the re-seller part numbers change, the if OEM remains the same then the part is the same. Same issue mentioned elsewhere on here regards the Rotax starter motor and that fitted to a jetski/snowmobile.

How could Rotax prevent you from fitting the same item?

BING AGENCY INTERNATIONALSOLE DISTRIBUTORFOR BING CARBURETORS AND THROTTLE BODIES IN THE US, CANADA,SOUTH AMERICA AND AUSTRALIA - Bing Carburetor Home
 
That is the case for the 912's but all the 914's I have seen the bowl bolts on. Maybe yours is a real early one?

wolfy
I have not seen one with bolts please can you post a pic .... all I have seen have the cam over clip ? In fact Google shows images with the clip and now u have me looking for the one with bolts?
 
Rebuilt my Rotax 914 carbs last year. Only one fixing bolt underneath the bowl, as per Georgio744's photo. If you torque this retaining bolt above the specified torque in the Rotax Maintenance literature, the bowl will distort and splay the pillars guiding the movement of the floats and cause the floats to malfunction. JH
 
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