Hey guys

I was just wondering if anybody has tried Royal Purple
oils in their Harleys. The reason being is the performance
shop where I buy my Royal Purple for my Jeep also has
the full line of Royal Purple for motor cycles as well. I'm
thinking of putting Max-Cycle 20/50 in the engin and Max Gear
75/90 in the transmission with the HD in the primary.
Any feedback will be greatly appreciated.

Crazy Canuck[sm=smokin.gif]

 

Right now I'm running the RP 20w-50 car oil in my '87 Sloptail. I've been very satisfied with it; bike runs cool, little lifter noise, and oil use is same as with other synthetics I've run. I'd imagine the bike stuff would be fine, just more expensive.

 

Thanks for the reply Poco. I could always count
on this website for quick and reliable feedback.
The price is $10.99 cdn funds/quart which is the same
price as the Syn3 from the dealer. So I guess
Purple it is. Anybody ever tried the Max Gear in their
transmission?

Crazy Canuck[sm=smokin.gif]

 

I am a contractor by trade, and did a job for a engineer for BP/Amaco, and he was telling me that Royal Purple has a form of a "MOLY" (Sorry, I can not remember the actual word) and it is very slippery when new, but if left in for awhile, it will turn into a type of sludge! This is something they were looking into putting in Castrol oils, but decided not to due to the sludge factor! Is it good oil? He said yes, If not left in to long! I asked what does thiat mean? He said, all he would say is "HE USES MOBIL IN HIS CARS", and that should speak for it self!
He had this "MOLY" and I did see and feel it, yes, very slippery, but at the bottom of the can was sludge! You can take my word, or you ca not, it is up to you! I would not use it after he shown me what will happen!

 

I have used Royal Purple for quite awhile in my vehicles (cars, jeeps, pickups, SUV's, Harley's, etc.) and at work (150 HP Screw Compressor, company cars) and have had great results and have not heard or seen any of this 'sludge'.

click here--> Longview Inspection on HD TC88

Skip, I didn't know you were a RP man! I figured you for a Mobil 1 kinda guy.....

p.s. years ago we use to add molybdenum disulfide to differentials, gear boxes, transfer cases, etc. in the oil patch for its lubricative properties.

 

Dave, I'm a "whatever I wanna try next" coupled with "as long as it's fairly cheap" kinda guy. Ran the car-type Royal P 20w-50 for 3400 miles, which is longer than I usually go between changes. Changed it last Sunday and slopped in some Castrol Syntec 20w-50. I check my oil tank at every change - no sludge in it from the Royal Purple. Not sure what the BP/Amoco guy was referring to when he told about the "moly" in RP, but I looked at a virgin oil analysis of some RP 10w-40 (no 20w-50 in the archives) and it had 117 ppm Moly(bdenum), which is fairly low, and normal for a 10w-40. There was nothing else in it that I wouldn't expect to see, so ...?

I'd use it again if I could get as good a deal on it as I did last time.

 

Skip, great minds think alike or are plotting something... (my granddad used to tell me that...) anyway, I try to buy the Royal Purple in 'bulk' whenever we change out our screw compressor oil so I get a little better price. The distributor was telling me that it was too bad I had a wet clutch because as far as he knew the only difference between the regular and MaxCycle was the wet clutch friction additive and the regular was 'a lot cheaper'. I told him 'Great' since my wet clutch runs in a separate bath from my crankcase I could buy the cheaper one in 20W50. After that we got into a slight argument and after I called him a horses *** after he still disagreed with me after I showed him the oil piping diagram for the motor / transmission / primary, I haven't bought anymore from him. Thank goodness NAPA and O'Riellys is carrying it now...

 

2006 FXST/standard carb-4000miles oil change today. 20W50 Syn Royal Purple in motor. AlsoRPMax Gear 75W140 in trans. Nothing for primary yet (Syn3 in there from 1K stealer service). And HD oil cooler. All in one day under a shady parking lot. Supported the bike with wood blocks to level. Bought an auto filter wrench from Pepboys. Works Ok, crank sensor is fine. Small amount of fine metal powder on both motor and trans drain plugs. The motor fluid came out dirty/dark in color. The trans fluid came out as really milky dirty looking tan color crap. I had Syn3 in all 3 holes. Both drain plugs were found very loose with some teflon thread seal on them, and had to replace both o-rings and put thread sealer. On the other hand, the filter was so tight, I had to use breaker bar and filter wrench.One cooler hose clamp broke. They all look very filmsy. Replacement from Pepboys, again. Started the bike and ride around the block. Everything looks so far so good. The shifting is way better now. The motor is running alittle smoother/ quieter. Cooler install was very hard without bike lift. I put 3L in motor and it's showing full. Isn't that supposed to be 3.3-3.5 L?

 

Ran the 20w50 "car" oil in my last RK Evo, now with 110k miles. Heads never off the bike and no signs of wear based on performance. Compression same as in 1997, the first of yearly checks, last being 2006 which showed 160/160. Always had low oil consumption, no change there either. Also ran very cool, oil hitting 200° twice durring my ownership, rarely over 180° even in summer traffic.

 

This is why I hate reading oil forums, because of patently false information being passed off as fact. I pulled the front rocker cover on my old RK at 100k miles and there was no sludge at all. Zero. Checked rocker shafts and bushings which revealed new specs--no wear. That bike has run RP 20w50 "car" oil for 110k miles and the heads have never been removed. The only item removed from the engine, except the nosecone to install an Andrews cam back in 1998, was this rocker cover.

You don't see "moly" lying at the bottom of an oil can. You should check your facts before repeating information that is obviously baseless.