Prerotator Problems

Gyropilot007

Highly Mangled RAF-2000
Joined
Nov 19, 2003
Messages
547
Location
Northwest Indiana
Aircraft
RAF-2000 Highly Mangled
Total Flight Time
500 Airplane 150Gyros
Guys:

I need some help. Since I installed my new 2.5 engine I've been having some problems with the prerotator belt. The problem is that the belt will not stay aligned. The end of the belt that is on the engine pulley creeps off of the center of the pulley torward the engine. The net result is that the belt rubs and gets hot and the prerotator does not work effectively. Any suggestions as to what I can do to keep the belt tracking correctly???

Thanks,

Bob
 
This is the best solution. The pulley is the belt tensioner from and ej-22. We never have any further troubles after conducting this mod.

Aussie Paul.:)
 

Attachments

  • Pre rotator belt tensioner mod. 2  .jpg
    Pre rotator belt tensioner mod. 2 .jpg
    76.9 KB · Views: 1
  • Pre rotator belt tensioner mod 3 .jpg
    Pre rotator belt tensioner mod 3 .jpg
    36.3 KB · Views: 1
  • Pre rotator belt tensioner mod.   .jpg
    Pre rotator belt tensioner mod. .jpg
    81.8 KB · Views: 1
Here's how some are doing it on the Sparrow Hawk.
 

Attachments

  • Pre1A.JPG
    Pre1A.JPG
    48.7 KB · Views: 1
  • Pre1B.JPG
    Pre1B.JPG
    47.3 KB · Views: 1
  • Pre2A.JPG
    Pre2A.JPG
    50.8 KB · Views: 1
  • Pre2B.JPG
    Pre2B.JPG
    36.4 KB · Views: 1
Last edited:
I'll second Paul's fix on this one, Bob.

That's a long span on that belt from pulley to pulley and just a microbit of allignment problem will cause what you're experiencing now.


Cheers :)
 
You certainly don't need two pulleys. The drive side (top) stay stight, it is the "loose" or non driven (bottom)side that "flaps" around.

The great part of the pulley from the ej engine is that the hole for the bolt to go through is off center and twisting it tightens the belt. Very similar to the concentric used in the main drive belt system.

Aussie Paul.:)
 
Easy goes it, Paul.

More than one pulley may be superfluous but if one wants to put four of 'em on there...that's their prerogative.;) :D


Cheers :)
 
For sure Harry....

For sure Harry....

Harry_S. said:
Easy goes it, Paul.

More than one pulley may be superfluous but if one wants to put four of 'em on there...that's their prerogative.;) :D


Cheers :)

....For sure Harry. I like the look of the plastic pulleys, nice and light, and I would use just one on the "loose" side of the belt as that is my perogative.:D :D :D

Aussie Paul.:)
 
Thanks

Thanks

Guys:

Thank you for all the great help. I'm definitely going to put an idler pulley on my machine. Beside keeping the belt centered it will greatly reduce belt flap and in my opinion, that's a good thing.

Best regards,

Bob
 
Idler pulley part numbers? Sources?

Idler pulley part numbers? Sources?

Thank you for all the great help. I'm definitely going to put an idler pulley on my machine. Beside keeping the belt centered it will greatly reduce belt flap and in my opinion, that's a good thing.
OK, my friends. I'm getting stopped at every turn trying to locate and purchase a suitable idler pulley for my EJ22.

Pep Boys, believe it or not, couldn't find anything in their computerized inventory system about "idler pulleys"! The fellow from AAI hasn't returned my call about parts from them. NAPA wants to know a part number. Fenner Drives on-line catalog lists a zillion different pulleys. Whew... how frustrating it is trying to accomplish such a simple task.

Does anyone possibly have a part number or complete description of this bugger, with a suggested source (store) to visit? I need this thing ASAP 'cause the darned new prerotator keeps chewing up my belts!

Thanks for your assistance,
 
O>K Guys

OEM 13073AA142 is part number. Roy Rogers in Little Rock will ship them to you If you have a Subaru dealership they should have them. Cost at Roy Rogers is 55.95
 
Last edited:
Gary

The metal one is the OEM one Pic 3 and 4 in Post number 4 above. You will also need to buy a bolt and spacet to keep it off the redrive and away from the engine.
 
Gary

The metal one is the OEM one Pic 3 and 4 in Post number 4 above. You will also need to buy a bolt and spacet to keep it off the redrive and away from the engine.

Great stuff! Thanks to both of you. The part is on order! YAY! :usa2:
 
Yahoo! I got them!

Yahoo! I got them!

Just got back from the Subaru Parts Department with two of those babies in hand. I'll install one of them to see how things go, and if need be, I'll install the other one. Will post pictures during installation and after the job is finished!
 
Aaahhh...good man, Ed. That's what we need, pictures are worth more than words. :D


Cheers :)
 
I bought the pulley set from I'M FLY'N for my RAF. It's $75 plus shipping, for both the pulleys and the bolts. You have to tell them it's for an RAF, and which engine you have.

I initially only installed the flat idler pulley, and that seemed to work for about 4 flights. Then the belt creeped forward. So I installed the grooved pulley also, and now the belt stays in place.

One note: I had to put washers behind both of my pulleys to get them to line up properly with the belt.
 
Hey guys, don't forget the turnbuckle support that some are using to keep the clutch end assembly pulling at parallel angles to the redrive.

Marty Weaver & I believe Duane Hunn are using them.

It made sense to me!
 
Hey guys, don't forget the turnbuckle support that some are using to keep the clutch end assembly pulling at parallel angles to the redrive. Marty Weaver & I believe Duane Hunn are using them. It made sense to me!
I'd really like to see some pix of the turnbuckle installation, if possible. The only way I see to install one is to make it a "push" type operation instead of a "pull." Thanks very much.
 
Top