RAF belt numbers

[StanFoster]

I want to have a spare prerotator belt and a spare alternator belt onboard for my EJ22. I never had the cross referenced numbers for these belts. Anyone have these handy? My RAF kit was purchased new the beginning of 2002. Thanks in advance. :D

Stan

[KenSandyEggo]

Stan, the alternator belt is 270K4 and the prerotator belt is 425K6. NAPA has the prerotator belt as K060425. You should be able to cross-reference with any brand with these numbers. Most auto supply stores have books with all the manufacturer's numbers and their equivalents from the other manufacturers. Do you realize that you have to remove the prop to change the alternator belt? Wish someone would invent one with a zipper crossways or something.

[StanFoster]

Ken: Thanks for the numbers. No..I wasnt aware of having to remove the prop for the alternator belt exchange. I still have a lot to learn on this machine..and you have my head scratching. I am going to the hanger the first thing to see about this. :D

Stan

[rgraffeo]

Stan,
I have some different part numbers for the belts:
Alternator: Dayco 5040285
Pre-rotator: Dayco 5060425
Also I think Ken was trying to say that the prop & drive belt has to be removed to change the pre-rotator belt. I've changed mine before & found it easier to remove the entire prop & upper drive assembly from the engine drive plate. That way the pitch of the blades won't be effected.

[StanFoster]

Rudy: Thanks for the numbers...and right after I posted about the alternator belt...I realized that Ken had to have meant the pre-rotator belt.

I would take the whole assembly off as well...rather than having to repitch the blades.

Stan

[KenSandyEggo]

What kind of props you guys have that you would have to repitch it if you took it off? I'm assuming you have Warps. I had my Warp leaning against the hangar wall for a couple years and just put it back on without having to repitch it. What gives? :confused:

Yes, I meant that to change the prerotator belt, you have to remove the prop and main drive belt. :o

[rgraffeo]

Ken,
I do have a Warp Drive prop.

On mine six long bolts attach the prop hub to the drive. These bolts along with six shorter bolts adjusts the prop pitch. If I were to remove the six long bolts to remove the prop hub, I feel it may mess with the pitch settings.

That is why I remove the entire upper drive along with the prop. I found this easier.

[KenSandyEggo]

It won't mess with the pitch settings unless you loosen the bolts that allow you to change the pitch.....the short bolts. You don't have to loosen those to remove the prop. The bolts that hold the assembly to the hub won't affect the pitch. I haven't tried your way, but I see where it might be easier.

[davreich]

Hi,
Not my current drive belt but I hope this helps.

[davreich]

Almost forgot,
Don't tell them it's for a gyroplane. Tell them an irrigation pump or whatever.

[StanFoster]

Dave: Thanks...If I ever buy a prop belt..I will say its for an air pump :D

[Harry_S.]

Hi y'all;

This is all real good info and would be beneficial to all RAF drivers. Don't you think it would be more beneficial if it were all stored in one place, for future reference and for new owners? Ref. RAF owners/drivers.

[StanFoster]

Harry: I was post flighting my RAF and just noticed a split down one of the grooves on the pre-rotator belt. So......looks like I will have to replace it immediately. Roughly how many hours should a guy expect out of this belt? I have 69 hours on the tach....but the first 20 were tied to a tree.

[Mike Hook]

Just a thought and it may not be a good one, but on equipment that I service that has problems on replacing belts we put on a spare and cable tie it out of the way. I am not sure is this is a good idea and I am sure that it would not work on the redrive belt but for a prerotor or alternator belt it may not be a bad thing if you think that you might be out were servicing a belt would be hard.

Mike

[KenSandyEggo]

Mike, that is an excellent idea! I don't know if it's feasible for the prerotator belt, but I'll sure see if it'll work. When I got my RAF, they sent me the new prerotator assembly but did not send me the pulley with the flange. Everytime I took off the belt broke. I'd have to take off the prop each time. If this worked, I would have put ten of them on there. Peter suggested shimming this and shimming that, all to no avail and a broken belt after each "experiment." After I sent photos, they went "duuuuh,".....we sent you the wrong pulley. I used to get the preferred customer, frequent-buyer discount on belts at NAPA.

[Chuck_Ellsworth]

Kenneth:

Do you still get the preferred customer treatment from Peter, Don and Linda now? :rolleyes:

[KenSandyEggo]

Whom? Sounds vaguely familiar.

[Harry_S.]

Stan:

I had a problem with my first pre-rotater belt. It wanted to fold the leading edge over onto itself. I would put pressure to the rear on the belt and hand rotate the prop to get it back in groove.

When I received my solid prop hub, I made some changes.

I used 3/8 in. Gr8 bolts, installed bolt heads forward, for much easier torquing. I had to trim about 1/2 in. of threads off the bolts. I installed a new pre-rot. belt, was very careful to check allignment on this belt. I think my belt has one open groove on the forward face of the crank sprocket. This belt has been on there now for over 300 hrs.

Suggestion; eyeball the grooves on both pulleys for a possible burr. You could have gotten a defective belt?

[StanFoster]

Harry: I replaced my pre-rotator belt today. I just took the nuts off the 6 bolts and removed the whole prop assembly, then took off the crankshaft support plate and checked that bearing. I thoroughly checked the alignment of the pulleys..looked for any rough spots...found none and reinstalled. I have the head of my bolts also forward. I checked the pitch of each blade just in case...but they were still right at 13 degrees,,,then I flew it for an hour today and retorqued all the bolts. Time will tell how long this new belt lasts. It had 75 hours on it...the first 20 were on the ground tied to a tree.

How tight do you run your pre-rotator belt/ I initially think I was running mine too loose to put less load on the clutch bearing...but now I have it snug.

Stan