What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Throttle Return Spring

n74846

Well Known Member
I just replaced my fourth MacFarlane spring (245 hrs. TT) and called Van's to order more. I was told they are suspended and unavailable at this time. I asked for details but none were given. Is anyone aware of any internal review of the product? There seems to be a recurring theme in the posts.
 
Steve,

I stopped breaking throttle springs after I had the prop dynamically balanced. Been well over a year now with no further issues. Regarding the replacement springs, you might want to call MacFarlane directly.


Alex
 
Is anyone aware of any internal review of the product? There seems to be a recurring theme in the posts.

Use of the currently supplied spring is being reviewed... more on that in the future.

In the mean time, the unavailable status has been changed so there is a limited number of the current part # available from Van's for replacement parts.
 
Thanks for the update and balance suggestion. The prop was dynamically balanced upon certification, 245 hours ago. What is the frequency recommendation?
 
Steve,

If the dynamic balance was done properly, I would think it would be good until the prop was disturbed somehow (re-adjustment of the pitch, etc).

Like you, I had gone through four or five springs. The person I spoke to at McFarlane suggested a prop balance if it had not been done. I was skeptical, but had it done anyway. It cured the problem for me.

Alex
 
Thanks Alex. Among other remedies I will invest in another dynamic balance. I'm sure that will improve things.
 
I must have a one off. I purchased an RV-12 a month or so ago and it's throttle spring does not return the throttle arm to idle, rather it does it's level best to send it to about three grand every chance it gets.
 
I must have a one off. I purchased an RV-12 a month or so ago and it's throttle spring does not return the throttle arm to idle, rather it does it's level best to send it to about three grand every chance it gets.

Depending when it was fabricated...you want the newer throttle cable,as it fixed the constant chase of the throttle creep.
 
I have flown one RV-12 with bad throttle creep, and it was really annoying. Mine hasn't had that problem. The McFarlane site has replacement packing for the friction lock. The absolute best solution, though, was to install the vernier assist throttle cable assembly. It wasn't difficult or too time consuming to install, and although it's pricey I have to say it's been worth the money and effort.
 
Get Home Depot springs and cut to length. My throttle is very smooth with no creep. They have been in place 5 years with no issues. I tried some HF ones first and they broke.
 
Get Home Depot springs and cut to length. My throttle is very smooth with no creep. They have been in place 5 years with no issues. I tried some HF ones first and they broke.

Do you remember which spring you started with? Their website shows a ton of springs, some obviously not the ones, others not so clear.
 
When I went to Home Depot they had two that were close in length to what I needed. as I recall it was the 0.037? diameter wire coil spring. They have one that is about 0.048, but it?s too strong. You?ll have to cut it to length and bend up one half coil to form a hook. Just make sure it is under slight tension with the throttle shut.
 
Use of the currently supplied spring is being reviewed... more on that in the future.

In the mean time, the unavailable status has been changed so there is a limited number of the current part # available from Van's for replacement parts.

Does anyone know the current return spring part number (for the Vernier Throttle)?
 
Does anyone know the current return spring part number (for the Vernier Throttle)?

Van’s telephone support tell me they no longer supply RV -12 Vernier Throttle Rotax Throttle Return Springs. They referred me to McFarlane Aviation.

McFarlane Aviation lady who answered said she knew the RV-12 part number off by heart.
She supplied spring McFarlane P/N 7235

Edit, 3 March 2018. See my later post 20 below - McFarlane Tech Support have given more accurate advice, they now say should order spring kit p/n 7140 that contains left and right springs. These are colored Red for L/H spring p/n 6822 and Blue for R/H p/n 7235.
 
Last edited:
carb spring

I got the same referral from Van's, but, for some reason I ordered P/N 6822. I'm not seeing P/N 7235. Are there multiple springs?

-nick
 
I got the same referral from Van's, but, for some reason I ordered P/N 6822. I'm not seeing P/N 7235. Are there multiple springs?

-nick

I looked at McFarlane web site and saw same thing. If search their site it comes up with a P/N(if I recall correctly 6822), but if you phone them the lady who answered chuckled that she knew the RV-12 P/N off by heart, and sent me the P/N 7235. I also could not find the 7235 on their web site.
 
Last edited:
This is from McFarlane Aviation in response to an email I sent last night.

Good Morning John,
Thank you for the inquiry on the springs. Yes, we now have a spring kit p/n 7140 that contains left and right springs. These are colored Red for L/H spring p/n 6822 and Blue for R/H p/n 7235 as seen below. The engineers have developed the new spring for the right side that helps align properly. I have attached the new instructions for installation of the springs for your reference. Our website does not have the new spring or kit listed yet, but they are available for sale. I am not sure if Vans has those yet or not? Hopefully that is helpful information. Please let me know if you have any questions.



Ben Strahm
McFarlane Aviation Products
McFarlane Aviation, Inc.
696 East 1700 Road
Baldwin City, KS 66006
800.544.8594 ext. 215
785.594.3922 Fax
[email protected]


They also sent an instruction on how to install, but I do not know how to post the pdf on VAF.
The installation instructions require “Remove upper B throttle arm piece from the
carburetor shaft.”
 
Last edited:
That there is a right and left spring is good news. I've always thought that one side seemed to not fit quite as well.

Thanks for checking into this. And, thanks to the McFarlane crew for the improvement.

-nick
 
This is from McFarlane Aviation in response to an email I sent last night.

Good Morning John,
Thank you for the inquiry on the springs. Yes, we now have a spring kit p/n 7140 that contains left and right springs. These are colored Red for L/H spring p/n 6822 and Blue for R/H p/n 7235 as seen below. The engineers have developed the new spring for the right side that helps align properly. I have attached the new instructions for installation of the springs for your reference. Our website does not have the new spring or kit listed yet, but they are available for sale. I am not sure if Vans has those yet or not? Hopefully that is helpful information. Please let me know if you have any questions.



Ben Strahm
McFarlane Aviation Products
McFarlane Aviation, Inc.
696 East 1700 Road
Baldwin City, KS 66006
800.544.8594 ext. 215
785.594.3922 Fax
[email protected]


They also sent an instruction on how to install, but I do not know how to post the pdf on VAF.
The installation instructions require ?Remove upper B throttle arm piece from the
carburetor shaft.?

New info.

Now Van?s themselves have designed theit own left and right springs (Van?s Part No SPRING-00002-L/R-1). They are not the same as the McFarlane ones Ben Strahm from McFarlane recommended above.
Van?s support emailed me
?They are not the same springs (as the McFarlane Red for L/H spring Mc Farlane p/n 6822 and Blue for R/H McFarlane p/n 7235).
See section 50-05
http://www.vansaircraft.com/pdf/revisions/RV-12/RV-12_50.pdf

From our SB 18-03-06:
NOTE: This spring design is supplied by Van?s Aircraft and
not available through McFarlane Aviation Products.

Van's Aircraft, Inc.
14401 Keil Rd NE
Aurora, Oregon 97002
503.678.6545?
 
Use of the currently supplied spring is being reviewed... more on that in the future.

In the mean time, the unavailable status has been changed so there is a limited number of the current part # available from Van's for replacement parts.

Scott, I ordered Van?s springs, however I have a vernier throttle. Guess I have some extra springs now and must order McFarland springs errr I?m confused. I?m not a builder. Thank you!
 
Use of the currently supplied spring is being reviewed... more on that in the future.

In the mean time, the unavailable status has been changed so there is a limited number of the current part # available from Van's for replacement parts.

Scott, I ordered Van?s springs, however I have a vernier throttle. Guess I have some extra springs now and must order McFarland springs errr I?m confused. I?m not a builder. Thank you!
 
The new spring from Van's, detailed in the Service Bulletin are designed to be used with the vernier throttle in place of the ones supplied by McFarlane
 
Back
Top