Jump to content
  • Welcome to Recreational Flying!
    A compelling community experience for all aviators
    Intuitive, Social, Engaging...Registration is FREE.
    Register Log in
Sign in to follow this  
rhtrudder

914 power loss

Recommended Posts

Sometimes the original cork gasket is difficult to seat properly.

 

I had one leak after checking the bowls.

 

Ended up removing the carb, sitting up side down on a bench, putting a very small dab of silastic on each corner, sitting gasket in place and fitting the bowl. Wait until set.

 

Now when checking the bowls, it doesn't fall out.

 

I've got a couple of wahoo rubber gaskets (as above) if you wanted to try them.

 

Faster than waiting for some from the states anyway....

 

 

Share this post


Link to post
Share on other sites
I didn't know about these ,so someone else has obviously had the same problem , thanks for the info rick , I will try and get some. Did you get yours from the states downunder how come you didn't use them.

 

 

Share this post


Link to post
Share on other sites
I didn't know about these ,so someone else has obviously had the same problem , thanks for the info rick , I will try and get some. Did you get yours from the states downunder how come you didn't use them.

Tip. Don't use any soft seal like aviation soft seal No3 to hold it into the garby as that product will cause the gasket to swell up larger and not fit the recess.

 

Been there done that.

 

Cheers

 

Mike

 

 

Share this post


Link to post
Share on other sites

Go check the Rotax ADs. From memory they was some issues with fuel permeating the floats causing them to sink a little. I think there was a test

 

one could perform to check this.

 

 

Share this post


Link to post
Share on other sites

So it was the float height, that's great easy fix. Don't ever use anything other than the gasket to seal the bowl. If it has been over tightened and warped it needs replacement with a serviceable item. Find a Rotax 914 experienced L2 or LAME in your area and get them to cast an eye over your work, it's amazing the things a second set of eyes pic up.

 

 

Share this post


Link to post
Share on other sites
I didn't know about these ,so someone else has obviously had the same problem , thanks for the info rick , I will try and get some. Did you get yours from the states downunder how come you didn't use them.

Yeah, bought same ones on ebay just to have a look at them. Original cork ones sealing OK and I have a couple of standard spares atm.

 

If I was to fit them, I would have a good look at how they fit and seat and if all looked good, give them a try. (Talking about me trying on my aircraft)

 

 

Share this post


Link to post
Share on other sites

Not many L2 around here pretty much on your own , have ordered those other gaskets , checked the floats ,filled up the float bowl an they both floated at the same level , the one that leaked was that on a 914 if it was leaking fuel did you have to adjust the float height

 

 

Share this post


Link to post
Share on other sites

Does the solenoid enrichment valve only switch looking at throttle position or does it also check against air box pressure , moving the throttle past 108 doesn't open the valve , any ideas?

 

 

Share this post


Link to post
Share on other sites

RHT, mate you done just about everything except a couple of things, I have had my share of trouble shooting with these engines, it only takes a small leak somewhere to up set the apple cart.

 

IMHO, the leaking fuel is not related to the power loss, more annoying than anything, there is no way that much pressure can escape through there, first off, make sure the pipes going to the turbo are seated properly, I have had 1 motor the bracket that holds everything in place, loosened, and(I think, long time ago) the exhaust rolled a small amount, and the top pipe was out of the socket, still sitting in there but not holding pressure(but it was still developing full power just a hell of a noise).

 

Next check all the small black pressure lines, especially the ones going from the carbs to fuel pressure reg, it sounds like it could be dropping fuel pressure, do you get a rapid rise in EGT's? when the power loss happens. take them off and put your finger over one end and blow into them so if they hold pressure, trust me these are very important pipes.

 

it is IMHO definitely turbo related as 36" is where the waste gate goes full closed, if all these things are good it could be turbo rebuild time, take your air intake pipe off, and see how much movement is in the main shaft, there should next to nothing side play, but a small amount of end float, check the compressor wheel, and turbine wheels on both sides.

 

Obviously before you take the turbo off the machine(if you decide to), make sure as stated before that the TCU is set correctly, it obviously does the full travel test when the power is turned on? if it is, the TCU/ waste gate/ controller, that's the problem, there should be flashing lights to advise of a problem there.

 

I have also had twice,(different motors) the waste gate motor just get that damn confused it "looses" it place and I took the cable off and turned the power on again, the motor does about 2 rotations then sets itself and all good then.

 

Is this a new problem? how many hrs on the motor.

 

Is there another 914 in the area? I would also try to swap test the air box pressure sender, ambient sender, in other words find another machine and swap senders out 1 at a time, see if you can find it that way.

 

Good luck you will need it :)

 

 

Share this post


Link to post
Share on other sites
Does the solenoid enrichment valve only switch looking at throttle position or does it also check against air box pressure , moving the throttle past 108 doesn't open the valve , any ideas?

What are you calling "solenoid enrichment valve" just that I have never read anything called that before? a search of the manual came up empty too.

 

 

  • Like 1

Share this post


Link to post
Share on other sites
What are you calling "solenoid enrichment valve" just that I have never read anything called that before? a search of the manual came up empty too.

What are you calling "solenoid enrichment valve" just that I have never read anything called that before? a search of the manual came up empty too.

It's called a enricher solenoid (or valve ). On full boost it switches to allow a bit more pressure ,taken from a different part of the air box , to give more pressure in the bowls , it's fitted to later model 914s , if I blow in the tube and move the throttle to full I still can't get and air through so I am unsure wether it also takes a pressure reading from the air box as well before it switches

 

 

Share this post


Link to post
Share on other sites
RHT, mate you done just about everything except a couple of things, I have had my share of trouble shooting with these engines, it only takes a small leak somewhere to up set the apple cart.IMHO, the leaking fuel is not related to the power loss, more annoying than anything, there is no way that much pressure can escape through there, first off, make sure the pipes going to the turbo are seated properly, I have had 1 motor the bracket that holds everything in place, loosened, and(I think, long time ago) the exhaust rolled a small amount, and the top pipe was out of the socket, still sitting in there but not holding pressure(but it was still developing full power just a hell of a noise).

 

Next check all the small black pressure lines, especially the ones going from the carbs to fuel pressure reg, it sounds like it could be dropping fuel pressure, do you get a rapid rise in EGT's? when the power loss happens. take them off and put your finger over one end and blow into them so if they hold pressure, trust me these are very important pipes.

 

it is IMHO definitely turbo related as 36" is where the waste gate goes full closed, if all these things are good it could be turbo rebuild time, take your air intake pipe off, and see how much movement is in the main shaft, there should next to nothing side play, but a small amount of end float, check the compressor wheel, and turbine wheels on both sides.

 

Obviously before you take the turbo off the machine(if you decide to), make sure as stated before that the TCU is set correctly, it obviously does the full travel test when the power is turned on? if it is, the TCU/ waste gate/ controller, that's the problem, there should be flashing lights to advise of a problem there.

 

I have also had twice,(different motors) the waste gate motor just get that damn confused it "looses" it place and I took the cable off and turned the power on again, the motor does about 2 rotations then sets itself and all good then.

 

Is this a new problem? how many hrs on the motor.

 

Is there another 914 in the area? I would also try to swap test the air box pressure sender, ambient sender, in other words find another machine and swap senders out 1 at a time, see if you can find it that way.

 

Good luck you will need it :)

Thanks a lot for your interest, against all advice I ended up using a fuel tolerant gasket goo, I know I will be crucified for it but in the end it was the only way I could stop the leaks , the fuel leak was of high float levels, bought the gold plated tool and fixed that , easy, but still had air leaking , I could actually hear it when I blew down the vent tube , have ordered the new upgraded bowls which are apparently more stiffer , on back order, so naturally I couldn't wait and glued the old bowls on , waited for 24 hrs for it to set and no more leaks , time for blast off, motor running like it should . I am the third owner ,470 hrs on the clock when I first hopped in now has done 1330 , for a complicated engine it has given me little to complain about , again bones thanks for your insight

 

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later for your post to be seen If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...