KTM updated 250/350 oil pump gear

Good to see KTM finally but the bullet and went to a metal gear. Not that plastic won’t work but there’s always gonna be a risk of heat induced warpage and failure. Once the oil pump stops working, the engine is toast. 
 

The metal gears are on the 23' 450, not the 250/350.  They do, however, fit the smaller engine just fine; I used them on my 17' 350.  The metal oil scavenging pump on the 450 is on back order, but as I understand it, fits the older and/or smaller engines just like the gears do.

My 23 250 has the metal gear. 

Hey,
I am just checking in on this seeing as I have a 350 xcf pulled apart right now.

I saw the older posts about KTM going to a glass filled gear since the plain plastic failed quickly, then I saw the updated AM aluminum big and small upgrade.

Now I am finding this post that the new ktm's have the steel big gear, did they update the little one on the pump to? or is that still plastic on the 23 models?

Just trying to sort out what is the best option for this bike so I can do it once and call it good

Thanks

There’s a metal small gear also. 

Do you happen to know the part number for it?

I've been looking at different 23 models (250, 350, 450) trying to figure out the part number but nothing can confirm that it is a metal one.

Yeah, I think there may be some difference in what the parts diagrams list and what the 23 bikes actually shipped with.  Anyway, here’s the plastic and metal versions with part numbers.  
 

Also, I want to clarify what Matt Fisher said above.  The older model 450’s came with the steel pump rotors where the 250/350 used plastic.  The steel drive gears come from the 23 and newer 250’s (probably 350 also).   So, ideally you’d use the newer 250 gears and the older 450 pump rotors to get an all-steel bulletproof setup. 

Good call. Never reuse that lock washer.  They are a real liability if the tab breaks off from fatigue.  
 

The bigger 22mm side steel pump rotors were back ordered forever, like 8 months.  They were just recently in stock.  Not sure about now.  

Sorry to hijack, but it appears there's some knowledgeable people in here.  I've got a 22 GG 350 (last gen motor) and these plastic gears are wearing heavy on my mind.  Anyone know how many plastic gears the last gen motor has and what the best replacements would be?  I'm looking to replace these over the winter tear down session.  TY!

Looking at part numbers and diagrams it looks like these new part numbers in the 23s will work in the previous gen 250/350 as well. $17 is certainly way cheaper than the aftermarket metal gears that have been available

The aftermarket aluminum ones have issues also.  It seems these shops crank them out on a cnc but they are not hard coated or treated, just raw alloy.  So they get chewed up over time since they are driven off the steel primary gear.  I’ve seen some pics of bikes with cruddy oil and chewed up gears.  

Ah I see that makes sense. Going to probably just get the new OEM steel ones to go on my 2021. This use is pretty good for plastic gears to be honest and by the numbers 99% of people never have issues with them. 

Thanks again for the info!

My local dealer ordered me 77038001200 (23 450 oil pump gear) and 79238006300 (23 350 oil pump intermediate gear), but said the 59038011112 (23 450 oil pump rotor) is on back order with no ETA.  I checked RM and they had one in stock, so I jumped on it.  Motosport also allowed me to add it to my cart, so they may have some in stock too for anyone else looking.

I just picked up a 22 KTM 350. Is this something I should replace ASAP while I have it stripped down for deep maintenance? 

How many hours?   I have a 2020 FC350 with 100 hrs, all MX tracks, not trail riding.  Just opened it up yesterday.  All the plastic gears and plastic rotors looked perfect.  I change my oil and filter every 5 hrs and the inside of the engine looks brand new.  

It has 90 hours. 

Do you know the history of the bike?  Did it have frequent oil changes with good oil? 

You can inspect all the parts pretty easily.  During an oil change while the oil is drained, pull the left side oil pump cover and you can slip the 22mm plastic rotors out to see if they have any damage or wear.  The steel ones are not that expensive and it's easy to slip them in there, if they are not backordered.  To inspect the plastic drive gears, you need to remove the clutch cover and then the clutch assembly to get a good look at the gears.  If they still look perfect like mine did, then you have peace of mind that failure is not imminent.  Make sure you put a new tab washer on the clutch hub when reassembling.    To replace the drive gears is a little more complicated.  You have to remove the entire right side cover, water pump (drain coolant), and the primary gear also.

I can only go off of what the previous owner told me, but oil change every 5 hours and it was raced MX. But, I trust very little in previously owned bikes unless I know the person. lol 
Since winter is upon me here, I will have time to tear the engine down to do a good inspection. 

PSA... if replacing the oil pump rotor make sure you order the 22mm rotor and not the 12mm rotor.  Thought I was gonna tackle this job last night, bu turns out I ordered the wrong pump rotor.

This is for a last gen 350 (22 ex350)

I see we made things kind of confusing how we jumped around in this thread, so I decided to make one, consolidated list of the parts needed.  The only absolute parts you need are the first 3.  The rest are a smart idea to replace while you are in there to make your oil pump 100%, especially if your bike has some decent hours on it.  I strongly encourage using a new clutch shaft washer.  The last part is the shifter shaft seal.  Not needed, but these like to leak.  And you've already got the engine torn down the exact same amount you need to replace this seal.  So might as well give it a look and replace while you are in there.  You will have to decide if you need a new cover gasket, water pump cover gasket, or complete WP rebuild kit since those have to come apart to do this job.  Also take a good look at your 6 clutch plate pins for any grooving as these are known to fall apart and wreck transmissions.

Parts list in text:

Big gear   79238006300

Small Gear   77038001200

Big pump rotor (left side)   61238011100

Small Pump rotor (right side)   59038011112

Clutch shaft lock washer   77232018000

Big gear shaft   77038013100

Big gear washer   0988121805

Big gear circlip   0471120010

Small gear Pin   0402251980

Small Gear washer   58038007755

Small gear clip   0799060000

Small Rotor pin   0402251180

Big rotor pin   0402041580

Pump cover O-ring   0770440020

Shifter shaft seal   0760142460

Yes.  Three small bolts hold the cover on.  Stupid easy to swap out.

Does it just slide out? I haven't worked on a KTM four stroke yet as I just purchased a 22 KTM 350SXF with 90 hours. While the winter months hit I'm slowly buying everything to freshen it up.