3DHELINUT

My Feedback: (3)

I picked up a new BVM 91, viofan and pipe and i have mounted the fan and engine on a test stand to break-in in the engine. so far i have run 5- 24oz tanks of wildcat 10% jet-a fuel at a rich setting, i started to lean the high end but i am unable to get the motor to come-up on the pipe. Can some one give me the carb setting for mid and low setting that will put me in the ball park. i have the engine docs but they are not of any help in setting up the carb for the right settings.



Thanks
Alan....

FalconWings

My Feedback: (57)

Alan,

The high carb setting is basically to lean it all the way in, then back off some. I always run mine on the rich side.

I don't know how you would set the mid range. I've never messed up with that, Im not even sure you can. Once the high speed setting ahs been achieved, everything else should be set. The only way of setting up the mid and low-range would be via throttle servo throw. I wouln't worry about the idle. Even at 5000RPM, the engine is not doing anything at all, so just try setting up the servo throw as low as you want without shutting it off.

I've never heard anything good about the fuel you are using. I always use Byron 5% Nitro, 20% oil and my engine has never quit on me. How many people can say they've never had a dead stick on a DF, well Im one of them.

Good Luck.

May I ask, what are you going to use it on?

3DHELINUT

My Feedback: (3)

The fan/engine combo is going in a BVM T33, I have been out of D/F Jets for some time and i need to brush up on my jet landing to get ready for my Skymaster Grippen which will get here some time in the next 7 to 10 days. I can not get a high needle setting that pus the motor on the pipe, adjusting the mid-range has helped but i still am not getting a good high end out of the motor. I fear that i have the mid range way out of wack and would like to re-set it and start over.



Thanks
Alan

Darryl Usher

Mid range is to turn the center screw in 360 degrees to get leaner, this is after you loosen the allen screw that is holding it, do not tighten too much.
This screw is the low speed adjustment and it is very sensitive. It lines up with a mark on the carb and adjustment is about .040.
None of this has any thing to do with on the pipe.
It is a BVM 91 and fan? Put your exhaust duct in place to support the pipe, put two stands out in front to guide the starting wand. to keep from feeding it into the engine or start by flipping back wards by hand.
Darryl Usher

3DHELINUT

My Feedback: (3)

What i am looking for is from a fully closed position how mant turns out should i set the mid range setting? I have made drastic changes to the mid-range and i want to set it back to factory defaults.

yes it is a bvm 91 and bvm viofan as stated in the origional post.

Alan....

mr_matt

My Feedback: (10)

No, the BVM indeed has independEntly adjustable mid range and low range mixture,. The importance of this has less to do with a low idle, but instead has EVERYTHING to do with a reliable transition from low to high.


I would start with the low needle maybe 2 or 3 turns out fRom being flush with the carb body, but it has been so long since I messed with them.

3DHELINUT

My Feedback: (3)

Thanks Matt, i will try that setting and go from there. I am also using an OS remote needle and do you think this may also be causing some issues?

Matt let me know if you guys receive my HP5 engine tomorrow.

Thanks
Alan...

mr_matt

My Feedback: (10)

Sure thing, but just so you know I don't work for JetCat some many times it is quicker for you to call them than to wait for me to talk to them.

I am absolutely happy to check for you, I just hate for people to be waiting on me, that's all

3DHELINUT

My Feedback: (3)

My mistake ----sorry , don't worry about it matt. i will call BOB tomorrow.


Alan

Rutlec80

My Feedback: (7)

Is the engine set up for a standard pipe or a puffer pipe? If it was set up for a puffer, it has a restrictor in the carb. Also may have extra head shims. I am just finishing a BVM T-33. Have a new .96 and should get the VioFan this week. Looks like my plane is going to be close to 20 lbs. What does yours weigh? Have a .91 and a VioJett, was in an F-16. Engine was turning 23.5K at 5400 MSL. Like to hear how yours turns out.

Thanks

Chet

3DHELINUT

My Feedback: (3)

i am not sure on the weight, i will weigh it when i get a chance. i am using standard pipe from BVM. I am going to change out the OS remote needle for a BVM inflight needle and go from there.


Thanks
Alan

FalconWings

My Feedback: (57)

Alan,

The BVM .91 that I had was pre-owned and pre-set. I never had to touch the needle setting at all. Once you have set it correctly you should never have to re-set it again. Is that awesome or what? Funny, at my field while others where fighting with the OS .91's, I would just get my F-16 out of my trunk and have it airborne in less than 8 minutes.

Man I really miss that Falcon.[]

Regards,

David

MMallory

My Feedback: (1)

Alan,

My offer still stands to help out. Bring it by my house or I'll meet you at U-fly one night. I was wondering what plug/fuel are you using and is the ducting installed while you are test running? What rpm are you getting now?

Mark Mallory

S_Ellzey

WildCat 10% Jet A is the fuel to use. I have used it for many years with excellent results, and so have many others. Before the turbine craze, WildCat was recomended by BVM for their engines.

3DHELINUT

My Feedback: (3)

Guys i am using a McCoy #9 and Wildcat 10% Jet-A fuel, i have also tried Enya #3 plugs.

I have enough knowladge in adjusting carbs from most D/F engines to get them running well but the BVM is different and after this experance i know i will never forget how to set a BVM engine.


Thanks for the offer Mark if i can not get it working after the carb re-set and mixture valve change i may contact you.



Alan....

FalconWings

My Feedback: (57)

I will deffintely keep this post handy. I have another BVM .91 that I don't know if I'll need to set it.