912ULS cross connect 'rubber hose' ID? Anyone?

[wildirishtime]

The aluminum crossconnect tube is custom for the Kitfox since the manifolds are moved - mine is 1/2" OD aluminum tube connecting to the Rotax 80degree elbows that thread into the manifold. They are .44" (11.3mm).

WHAT RUBBER HOSE exactly are you guys using for a PROPER (reliable) fit between the tube and the manifold? Can someone measure the ID on that rubber hose for me so I know what to order? Rotax orginal is kind of expensive if someone has the correct hose inside diameter I'd appreciate it. 1/2" hose doesn't grip the .44" aluminum elbow very well at all.....

Thanks in advance!
-Wild

[kitfox2009]

Hello Wild
I replaced the entire system with automotive vacuum hose when I installed my manifold pressure gauge. I connected the MP hose with a tee mid way. I discarded the aluminum section completely. Not sure about the diameter,just match up at your auto store.
Cheers
Don

[wildirishtime]

I too am adding MP to my MGL Xtreme in this process. Anyone have the appropriate rubber hose ID? Local stores are far away so ordering online is my friend....

[kmach]

Hi,
I installed a MAP sensor tee into the compensation tube in October, the hose used at the connections was 3/8" inside dia.
I needed to warm and manhandle the rubber onto the fittings and tube. (it isn't coming off)
1/2" inside dia is too big.

I see a 11.11 mm on one of the rubber connections on the compensation tube to manifold ,I believe this equals to 7/16" inside dia
I have been meaning to look for 7/16" or 11.11mm inside dia vacuum hose but it always seems to slip my mind at the store!!

[wildirishtime]

Thanks for replying Kevin, are you saying the Rotax rubber part has 11.11mm PRINTED on the factory original rubber cross connect tubes?

According to Google this would be 7/16". My "Kitfox" custom cross connect tubing is 1/2" (could have been a previous owners fault who knows).... I will convert to 7/16" if you verify my above question. Thanks a bunch!

[kmach]

Hi,
I can't say if these are factory or not, I'm the 3rd owner. but the short rubber tubes connecting my manifolds to the compensation tube have 11.11mm in white on them and they fit good.

[wildirishtime]

well i have a spare alum elbow here and it measures 7/16" plus as I recall the factory hose there is metric (first sign it's original) plus if it looks really high end with a fabric covering I thnk that's also a sign yours is original, verifying the measurement.

I'm Teeing in a manifold pressure feed to my RDAC and may have to go 3/8" to get a tee fitting that will work for me in brass, trying to do a one-piece brass tee to cut down on leak concerns. Last thing I want is something to fail and go super-lean on me!

In the interest of sharing, at this time I'm planning to go with a 3/8 x .17" x 3/8 solid brass barb as a Tee for my manifold pressure gauge and use 7/16" hose to connect it to the two manifolds. McMaster Carr link is here:

http://www.mcmaster.com/#44555k189/=fkc9lj

Part # if that link doesn't work is 44555K189

Thanks for your effort looking that measurement up for me! Appreciate it!

[kitfox2009]

Hello All
This thread is fairly old but maybe some of you "manifold pressure guys" want to chime in.
I installed my MP gauge ( good quality automotive style to match the other round ones) about 100 hours ago.
My question is:: what MP pressures are everyone running???
I have an IFA prop and normally adjust it after reaching cruise at full throttle. I coarse-up the prop as I am reaching cruise level at give 5500+ at full throttle. I then pull the throttle back a inch or so and set the prop at about 5/5200. My MP then is always over 28 inches.
It seems to get my MP down below 25 o26 inches I have to bring the RPMs back considerably.
Is this what others are experiencing.
It runs very well,does not "lug" or detonate, does not run hot and plugs look perfect. Is this OK for Manifold pressure??
Cheers
Don

[wildirishtime]

How goes Don? It was good to see you at Arlington. I did install my MP indicator with brass tees to my RDAC as described below on the MGL Xtreme EFIS but I don't have my IVO Medium installed yet so i'm certainly no help.

I look forward to someone else giving a good explanation on what is best - Rotax releases some data on this but I'd like to hear real world replies here too.

~Brendan