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View Full Version : 912s carburettor keeps falling off



Monocock
04-23-2011, 12:44 PM
I am hoping someone can help.

My 912s keeps throwing the passenger side carb on shut down or start up. It happens every hour or two. I have replaced the rubber and removed the limiter spacer on the clamp to get it nice and tight.

I have the Sting TL bracket mod to hold it in place and 3 springs to hold it secure. But it still keeps falling off.

I have the idle low (1700) to minimise the kick on shut down and the start ups are as smooth as I can make them with my procedure.

Any ideas?

moosepileit
04-23-2011, 01:53 PM
You need the spacer! Spacer or 7mm gap, per the specs, read the manual, please.

Monocock
04-23-2011, 01:57 PM
Moosepiliet

What 7mm spacer are you referring to please? I am unaware of a spacer for the carb and what it actually does.

DesertFox4
04-23-2011, 02:49 PM
Mono, I think he's talking about the clamp spacer you removed.



When was the last time you synced the carbs?
How many total hours on the engine now?



I use a shutdown method that reduces engine shake and kickback. It of course is predicated on a correctly synced set of carbs.
Just before shutdown set rpms to about 2200 to 2500. As you shut off the ignitions be pulling the throttle to idle stop and hold it there until the engine stops turning. Usually comes to a nice smooth stop with no compression stop or kickback.
Takes a few times to get it timed correctly but really helps for a smooth shutdown.

cainbird
04-23-2011, 05:18 PM
I just replaced my carb boots with the JBM brand boots. They specifically state in the mounting instructions to remove the spacer and tighten them up good!
Cain B

Monocock
04-23-2011, 11:21 PM
cainbird - that is what I was advised too.

DF4 - the engine has done 36 hours from new and the carbs are synchronised perfectly (did it two weeks ago). I will try your shut down method. What is your idle set at?

I am wondering if it would help having shorter air filters to reduce the moment arm weight on the clamp during start up and shut down. Just a thought...

DanB
04-24-2011, 12:38 AM
http://www.teamkitfox.com/Forums/showthread.php?t=2356&highlight=carb+bracket

Monocock
04-24-2011, 12:52 AM
Thanks Dan

That was when I thought I had it sorted!:(

sdemeyer
04-24-2011, 06:12 AM
My carb hasn't fallen off since I tossed the rotax sockets and installed JBM sockets. Was a real problem almost daily.

Monocock
04-24-2011, 06:22 AM
Thanks Scott. I will order a pair tonight. Is there a particular sort I need or is it a case of 'one size fits all 912 engines' ?

sdemeyer
04-24-2011, 07:56 AM
One size fits all for the 912.

Monocock
04-24-2011, 08:05 AM
2 rubbers paid for and on their way. Thanks folks.

PS Don (business owner) is a very helpful and efficient chap. It doesn't get much better than that.

DanB
04-24-2011, 09:09 AM
Thanks Dan

That was when I thought I had it sorted!:(


Ha...didn't look to see that was your previous post. I just remembered someone had put those on earlier and I was thinking of making some at one point... No intent of rubbing it in ;)