ktm oil pressure

Hello riders.

Can anyone pls tell me how to check the oil pressure on ktm 620 egs year 1995.Im afraid that my piston is running dry cause its making rubbing sounds and when i checked the oil pressure piston below the engine it doest move.. is should ?=

THX FOR HELP..

se ya on the road

Piston on the bottom of the motor is the pressure bypass valve. Not sure how much pressure it needs to move, but it is probably quite high.

Kinda vague, I know, but I really have no numbers for this.

I would be concerned about a "rubbing" sound. I'd think if the motor was running dry, you'd hear grinding more than rubbing.

Have you checked that oil dribbles out of the frame burp hole?

Check if there is oil moving when engine is running...

- Slowly loose upper banjo bolt on piston oil jet hose.
Is oil coming out?

- Slowly loose banjo bolt on clutch cover.
Is oil coming out?

Oil pressure piston moves against spring when you have too high pressure.

rubbing sounds could be the cam chain guides, or clutch related?

Creep officially commented on this recently:

http://www.advrider.com/forums/showthread.php?t=57107&page=12

See Posts #171 and 173. 171 includes a spec for the spring rate/length, and I believe the concern is for the the spring to fatigue over time and the valve open too easily, or vice versa

poco mas:
http://www.advrider.com/forums/showthread.php?t=155217

This oil pressure question has been raised before and I don't think I've seen a good answer on how people have done it or what is normal.

One of my bikes has a 96 duke frame. Those bikes have an idiot light for low oil pressure, do other models as well? There is a oil pressure sending unit screwed into a hole below the oil fill hole in the steering head. Its probably a simple switch that turns on below a certain pressure, lighting the warning lamp. Why not install a pressure gauge into the frame filler hole to see what a "normal" pressure is?

Perhaps even better:

Install a schrader valve in the top frame "burp" hole. This would allow for easy frame burping while changing the oil. Bonus feature: you could attach a simple gauge to it while the engine is running to check the oil pressure. I have used a regular tire pressure gauge to check the fuel pressure from the schrader valve on my Ford diesel. Why wouldn't it work here?

This might be my best idea yet, provided creeper didn't suggest it 10 years ahead of me. i better read the oil change thread again.:huh I'll try it on my two bikes unless someone convinces me otherwise.

i loosen the oil bold on the frame and the oil is getting around.. but thats only for getting the oil in the frame and around.. ill check everything out in a month when ill be shure that the temps wont be high enough to take myself on some corner grinding rides . until then i just use a mix of oil and gas like in 2t engines.. it cant hurt but it can definitly help a little... after the last 500 km the sound didnt changed.. that calmed me down a little, i guess if the piston would be too dry the rubbing sound would get louder.. a mechanic told me that theese engines are loud as hell and are making all possible sounds.. maybe im just paranoied cuz i aint used to listening all the parts in the engine .. lets hope for the best. thx guys for taking time to think with me

Like a farming combine.



Not sure I'd ride it as is if you are worried the noises are not normal, but it's your call.

Is this "rubbing" a new noise?

i dunno if its new .. i have this bike only a couple of weeks made 1300km with it.. it was there from the start.. but im 100% shure that engine had a complete rebuild 6k km ago.. and i guess only 3 possible explanations if something is not normal.
1. the oil piston doenst move therefore the pressure is too low (maybe ?)
2. when engine was rebuild it wasnt done good..
3. everything is normal and im just paranoied
i had problems with clutch hub, had to install new backplate and those things in the holes.. (my english is not so good )after i rebuilded my clutch sounds were same.. just a little less rattle in the clutch compartment.. i saw that bearing on main gear shaft was replaced with the roller one, seems like all the bearings were replaced, oil pumps resealed....ill see ill wait for 14 more days if the weather will be good, than im going to completly demolish the bike and make new wiering(this one is a mess), fix few problems(oil leak somwhere above cilinder)etc etc.. ill picture and archive everything ill do and probably post pictures.. have fun and ride well

The oil piston doesn't need to move under normal conditions. It is a bypass intended for situations when the flow may be blocked (like an incredibly dirty filter) and the oil needs somewhere to go to keep circulating.


I'm going with guess #3 that everything is normal and you are being paranoid. These are noisy motors and many many owners have felt the same uneasiness you are feeling about the sounds coming from the engine.

Keep a keen ear open when you ride and worry if you hear any new or significantly exaggerated noises.

Go have some fun.

+1 nico

the piston on mine didn't drop out with gravity, I couldn't get it out manually, i had to blow compressed air from the filter side to get it out. It slid back in easily during installation though. surface tension was holding it up there

finnaly some asnwers that calmed me down .. i love my bike and id hate that something would happen to him .. just to be shure ill try to unscrew the hose that brings oil to the piston and see if any oil will gush out just to be 100% shure that everything is normal..

Now i have another issue and i think its the last one before completing my check and fix for new season coming. My ktm is leaking oil on the caps of crankshafts.. the two aluminium pistons inserted in the cylinder head on left side. any ideas how to fix it?

I made another 1k km this weekend.. nothing really new.. the standart rattle clac bom bom... i think its standart ktm sound .. everything just rattles and vibrates.. but no differences.. last 2500km sounds were the same. i think im good .. pictures coming this week

Left side?
Cylinder head?
crankshafts?

Did you mean rocker arm shaft heads on right side of rocker cover?
Just above spark plug?

just above the spark plug..

There is only one o-ring sealing these shafts.
Located just outside rocker cover bolt that hold shaft on its place.

IF i remember correct shaft is long enought that these o-rings can changed without dropping left side shim washer...

Take bolt out.
Insert long thin screwdriver into hole to keep shaft coming too mutch out.
Use second screwdriver to slowly push shaft out just enought that o-ring is accesible.
Change o-ring.

I have read in a couple of places (that I can't remember) that it's well worth the effort to replace the seal on the end of the crank. You can see it between numbers 6 & 7 on the oil schematic. Apparently if you change that every 30 odd thousand the cranks/big ends will do 100,00 no worries. Sounds like cheap insurance to me I'll be doing it on my 625

Finally made time to do this. My oil pressure gauge was made from spare oil line and 10x1mm banjo bolt, various tubing fittings to connect it to a small oil pressure gauge from junkpile. I just screwed it into the steering head burp hole and started the bikes up to read the pressure in the frame.

Bike 1: 97 rxc 620, not sure what oil brand but about 600 miles since fresh. 4000 miles on engine. Pressure at idle barely lifted the needle, so lets say 5psi. with the engine revved I could push the needle to about 17psi. My bikes don't have tachometers unfortunately.

Bike 2: 95 rxc 620, fresh rotella synthetic oil, fresh oil pump from a conrod replacement, rest of motor has 8000 miles on it. At idle it was about 7 psi but that dropped as the oil warmed up. Revving the engine got me to 17psi again.

Observations: I think that the pressure in the frame reflects the pressure system-wide since its a closed system, but maybe the spin-on filter holds a little pressure? The oil pump doesn't make much pressure at idle. Perhaps the relief spring keeps things around 17psi when rpms rise. I could make oil move in the tubing by moving the kickstarter through.

Anyone else seen or tried to measure the oil pressure? I'll lend out my gauge if anyone feels the need to test their bike.

What is the redline rpm for a 620?

View attachment 200169

For some reason the pressure relief spring was missing from an order so I put the old one back in at last oil fill. The ktm manual says the service limit is 24mm. and it was close enough I thought. I put the new one in yesterday with a post-rebuild oilchange. The old one was .91 inches long, the new one .96. I need to get a metric vernier caliper.

I tested the oil pressure again with my makeshift gauge. Now the bike makes more pressure, almost 10 psi at idle and now the needle will pass 20 psi when revving the motor.

Maybe these springs should be looked at and replaced more frequently as part of the preventative maintenance. cheap insurance?

Now That is usefull info, Thank You!

I'm assuming that's the spring for #2 in the picture on the previous post? Could you post up a PN?