low oil pressure after 20+ kms of riding,radiator fan does not turn off during idle.

[shreeshar7]

there are numerous issues that came up after the engine rebuild.now the bike runs almost fine,but after 20+ kms of riding at speeds above 110kmph the bike shows low oil pressure,once it appears then its occarance freequency increases as i ride. dissappears and comes again after a while.
replaced oil pressur switch and still the issue is present.

also the engine runs hotter than it should,the radiator fan should go off after a while when bike is in idle,but in mine the fan is spinning and isnt cooling down enough for it to turn off
(89 degrees). even after leaving it idle upto 25 mins,the fan keeps running and bike is hovering at temps 90-92 degrees.(temps checked on OBD).

after i continue to ride after it shows low oil pressure ,it goes off for sometime and again it comes on.i also feel the gearshifts get a bit clunky after this.

what could be the issue?

 

[Fasteddy]

"what could be the issue?"

Excessive clearance on connecting rod and / or crankshaft main bearing. Were the main baerings replaced? Was the connecting rod big end bearing checked for radial clearance of less then .08mm?

 

[shreeshar7]

"what could be the issue?"

Excessive clearance on connecting rod and / or crankshaft main bearing. Were the main baerings replaced? Was the connecting rod big end bearing checked for radial clearance of less then .08mm?

Crankshaft is a bush system, And no they didn't check, they just assembled
What came from factory.

 

[Fasteddy]

Also have you put an actual oil presure gauge on it? either via KTM adapter or oil presure switch, inevitably it will start out with decent presure and go steadly down as the engine warms up.

Manual says to always replace the 2 slide bearings in the cases by heating the case to 150° C...
FYI, from the KTM manual:

– Position the bearing shells. Insert the Plastigauge clearance gauge
to the bearing face.
Plastigauge measuring strips (60029012000) offset by 90°(p. 226)
Position the conrod bearing cover. Mount and tighten the screws.
Guideline
Screw, conrod bearing M8x1 34 Nm (25.1 lbf ft)
Info Do not twist the connecting rod.
–
Remove the conrod bearing cover again. Compare the Plastigauge clearance gauge
with the specifications on the packaging.
Guideline
Connecting rod - radial play of lower conrod bearing 308107-01
New condition 0.045... 0.068 mm (0.00177...0.00268 in)
Wear limit 0.080 mm (0.00315 in)
Info
The width of the Plastigauge clearance gauge is equivalent to the bearing play.

–
Measure the crank pin diameter.
Guideline
Crankshaft – diameter, crank pin
Crankshaft classification A 31.970... 31.977 mm (1.25866...
1.25893 in)
Crankshaft classification B 31.978... 31.985 mm (1.25897...
1.25925 in)
Info
The crankshaft classification is indicated by marking





From spec page:
Crankshaft bearing 2 slide bearings
Conrod bearing Sleeve bearing

 

[shreeshar7]

Also have you put an actual oil presure gauge on it? either via KTM adapter or oil presure switch, inevitably it will start out with decent presure and go steadly down as the engine warms up.

Manual says to always replace the 2 slide bearings in the cases by heating the case to 150° C...
FYI, from the KTM manual:

– Position the bearing shells. Insert the Plastigauge clearance gauge
to the bearing face.
Plastigauge measuring strips (60029012000) offset by 90°(p. 226)
Position the conrod bearing cover. Mount and tighten the screws.
Guideline
Screw, conrod bearing M8x1 34 Nm (25.1 lbf ft)
Info Do not twist the connecting rod.
–
Remove the conrod bearing cover again. Compare the Plastigauge clearance gauge
with the specifications on the packaging.
Guideline
Connecting rod - radial play of lower conrod bearing 308107-01
New condition 0.045... 0.068 mm (0.00177...0.00268 in)
Wear limit 0.080 mm (0.00315 in)
Info
The width of the Plastigauge clearance gauge is equivalent to the bearing play.

–
Measure the crank pin diameter.
Guideline
Crankshaft – diameter, crank pin
Crankshaft classification A 31.970... 31.977 mm (1.25866...
1.25893 in)
Crankshaft classification B 31.978... 31.985 mm (1.25897...
1.25925 in)
Info
The crankshaft classification is indicated by marking





From spec page:
Crankshaft bearing 2 slide bearings
Conrod bearing Sleeve bearing

Hey.. Thanks for the info... When my engine was rebuild.. Entire case was also new since it cracked.. So I'm assuming the bearing was replaced with the case.

 

[Fasteddy]

So you can assume that the case bearings are good and the main journals to case plain bearings are not the problem.
Is there more rattle or knocking noise at idle / slight rev when the engine is nice and warm?


The first place the pressurized oil goes is the crankshaft bearings and connecting rod main. I currently have two FZ600 engines apart with excessive oil clearance on the connecting rod big end, I have seen this same issue many times on everything from motorcycles to all types of auto engines and even a tractor.

 

[shreeshar7]

So you can assume that the case bearings are good and the main journals to case plain bearings are not the problem.
Is there more rattle or knocking noise at idle / slight rev when the engine is nice and warm?


The first place the pressurized oil goes is the crankshaft bearings and connecting rod main. I currently have two FZ600 engines apart with excessive oil clearance on the connecting rod big end, I have seen this same issue many times on everything from motorcycles to all types of auto engines and even a tractor.

Daaamnn yess bro yes,
Theres a "grrk grrk" sound when slightly revved when the engine is warm..yess..
Please help me

What could that be??

 

[Fasteddy]

In an earlier post you said;
"I asked them to do a oil pressure test. It stays at 1.5 bars idle and 1.85 bar at 5000rpm."

Did you actually see this being done and see / read the gauge yourself ?

Page 185 of the service manual says:
Engine oil pressure:
Coolant Temperature ≥ 70° C Engine Speed:1500RPM ≥ 0.7bar (≥ 10 psi)
Coolant Temperature ≥ 70° C Engine Speed:5000RPM ≥ 2.4bar (≥ 35 psi)

So the numbers in that post make no sense!
The first thing to do is to get an accurate reading of the oil pressure with a decent gauge connected to an adapter made out of an oil filter cover or by removing the oil pressure sending unit and connecting it in it's place.
Then with the engine COLD start it and check at idle and at 5000 RPM, watch as it warms up and make sure the reading do not drop and stay close to spec (they won't) if it fails that test it is time to pull engine back apart and replace / check connecting rod big end plain bearing.

Not what you probably want to do but you seem to have eliminated everything else.

 

[shreeshar7]

In an earlier post you said;
"I asked them to do a oil pressure test. It stays at 1.5 bars idle and 1.85 bar at 5000rpm."

Did you actually see this being done and see / read the gauge yourself ?

Page 185 of the service manual says:
Engine oil pressure:
Coolant Temperature ≥ 70° C Engine Speed:1500RPM ≥ 0.7bar (≥ 10 psi)
Coolant Temperature ≥ 70° C Engine Speed:5000RPM ≥ 2.4bar (≥ 35 psi)

So the numbers in that post make no sense!
The first thing to do is to get an accurate reading of the oil pressure with a decent gauge connected to an adapter made out of an oil filter cover or by removing the oil pressure sending unit and connecting it in it's place.
Then with the engine COLD start it and check at idle and at 5000 RPM, watch as it warms up and make sure the reading do not drop and stay close to spec (they won't) if it fails that test it is time to pull engine back apart and replace / check connecting rod big end plain bearing.

Not what you probably want to do but you seem to have eliminated everything else.

Thanks a lot for your valuable inputs man..
Currently I'm in touch with my ktm area service manager.. He's the only sensible person who's trying to help me get this sorted, i will tell him about this and see how things go. Will keep you updated.
Thanks.

 

[shreeshar7]

Meanwhile they got the oil out of the engine thru drainbolt and evacuation stainer..when the stainer was taken out of looks twisted.. Could this have contributed to above problems.?

 

[CDN Duke]

I wouldn't suggest that was helping the situation at all, that's for sure. Almost looks as though it sucked onto itself, possibly contributing to oil starvation?

 

[cjwell]

In an earlier post you said;
"I asked them to do a oil pressure test. It stays at 1.5 bars idle and 1.85 bar at 5000rpm."

Did you actually see this being done and see / read the gauge yourself ?

Page 185 of the service manual says:
Engine oil pressure:
Coolant Temperature ≥ 70° C Engine Speed:1500RPM ≥ 0.7bar (≥ 10 psi)
Coolant Temperature ≥ 70° C Engine Speed:5000RPM ≥ 2.4bar (≥ 35 psi)

So the numbers in that post make no sense!
The first thing to do is to get an accurate reading of the oil pressure with a decent gauge connected to an adapter made out of an oil filter cover or by removing the oil pressure sending unit and connecting it in it's place.
Then with the engine COLD start it and check at idle and at 5000 RPM, watch as it warms up and make sure the reading do not drop and stay close to spec (they won't) if it fails that test it is time to pull engine back apart and replace / check connecting rod big end plain bearing.

Not what you probably want to do but you seem to have eliminated everything else.

Use an old oil filter door, drill and tap for 6x1 banjo then line to mech gauge. The oil filter must be installed!! You will get way higher, untrue readings without it inline. I had one that was a trans circuit issue oiling wise, big end rod was fine, don't rely on just that. Could be lots of places! Oil jet fallen out of clutch cover etc..

 

[shreeshar7]

"drill and tap for 6x1 banjo then line to mech Guage"
I don't really understand what that means..
Could you please elaborate and tell me in simple terms about what you suggest?
Thank you!

 

[Fasteddy]

"I saw the picture before I had to head in to work, Wow that is strange and I would not think it would get sucked in from the evacuation pump, more then likely it was not correctly installed, I don't think it changes much because from the pic it would seem oil could still flow through it. The numbers from the oil pressure test are still making no sense and do not fit with anything in any of your other posts. The behavior still sounds like oil clearance on crank bearing issue and is confirmed by knocking. The crank may have become worn from the screen issue not supplying enough oil but it is hard to say what caused what. At this point your still back to needing a good oil pressure test from cold to hot as I do NOT believe the numbers provided in your post.

The oil pressure test is going to tell if you need to open the engine again or not, it could be blocked passages, incorrectly assembled pumps, gaskets blocking passage who knows...

And you have continued riding it with what ever is going on which is probably made it worse. Not that it helps but if I had an engine that exploded cases I would not even rebuild it, Just find a used running one.

Good luck"

And what Chad says above is true, could be lots of places....

 

[Fasteddy]

"drill and tap for 6x1 banjo then line to mech Guage"
I don't really understand what that means..
Could you please elaborate and tell me in simple terms about what you suggest?
Thank you!

He is explaining how to make a gauge adapter like on page 185 of the service manual....

 

[shreeshar7]

An oil pressure test was done,
Readings are in kg/cm2.
In cold and hot the pressure did not drop.
Idle- 1.5kg/cm2
5000rpm-2.5kg/cm2
Measured from oil pressure switch socket.

Once the engine is hot after riding few kms, and fan kicks in, the fan never goes off at idle. And the temps drop a bit and again rise and sustain at 94.5 degrees in idle.
We tested with two similar rc 390s and in those under similar conditions the radiator fan turned off after a while.

 

[Fasteddy]

So fixing the suction screen solved the over heating?

1.5 bar =21.75 psi
1.85bar =26.83 psi

1.5kg/cm2 =21.33 psi
2.5kg/cm2 =35.55 psi

 

[shreeshar7]

Nope, not solved..its still overheating at idle.
They're now doing a compression test,I don't know why these guys did compression test on a bare cold engine.
Compression is at 8.5 bar.
I had a look at the spark plug..does this say something?

 

[Fasteddy]

It looks like it is lean, but these bikes run pretty lean especially with the catalytic converter. You still have the stock intake and exhaust on it?

 

[shreeshar7]

I too felt its running lean.. Yes completely stock bike.
The radiator fan now turns off for first two times when started cold. But keeps running in idle after it switchs on after some riding. Shuts off when I start to ride for few kms... Stays on in idle.