KTM Owners Forum banner

21 - 40 of 61 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter #21
are the rolling gears on the shafts running smoothly? they run on needle bearings, and if they're fooked the gears can bounce around until they're engaged.
Have you ever experienced the bouncing around when in gear?
The bearings look fine and feel fine but I am replacing them all anyway. At this point it's just worth it.
Once replaced I'll be putting it back together to see what it's like then.
 

·
Registered
Joined
·
540 Posts
I have, but with older bikes (Ducati 750 Paso having needle bearings, Ducati parallel twin with bronze bushings).
surprises you when you open the engine and see how much could have gone wrong!

was just thinking, could it have been a loose chain slider? because the noise in the vid isn't constant but it can originate from elsewhere...
 

·
Registered
Joined
·
57 Posts
Discussion Starter #23
The chain sliders are both OK - both attached and the pressure pushers for them look fine.
The thing is that the noise becomes much more pronounced in 3rd up.
Difficult to consider that it's anything but gearbox. The noise sure sounded like it was coming from the bottom back part of the engine.
I'm pleased that the symptoms I am experiencing can happen with bearings (it means it should simply work😁 when reassembled) .
There was no carnage in the gearbox though....
 

·
Registered
Joined
·
57 Posts
Discussion Starter #24
Just plumbing in the water, oil, petrol and electric and will be able to check results...
35335
 

·
Registered
Joined
·
57 Posts
Discussion Starter #26
Its not alive yet. It is still refusing to start.
I am following up from some potential fixes from @KevInYorks but have yet to make the time to do it.
With clarity regarding the TDC front and back with the full turn counter clock wise with its 75 degree angle I don't want to consider that I got that wrong at the moment.
Fuelling and sparks first - I will also be checking the connection to the sensor on the pulse generator cog.
Saturday will hopefully be the day of resurrection!
(Thank you for your input to. I really hope though that the engine does not need to taken apart again!)
 

·
Registered
Joined
·
57 Posts
Discussion Starter #27
So, there is a clean healthy spark. Spraying carb cleaner as easy start did not cause any firing => problem probably does not include fuelling.
When turning the engine over by hand there seems to be only one main compression every 720 degrees - from listening to the carb trumpets its from the rear. This leads me to agree with @charlie264 and @KevInYorks that the timing is probably out. When we did this with the 360 + 75 the engine stopping bolt went literally straight in - tdc. Knowing how diligent we were I am struggling to believe we got this wrong however the symptoms are all there. The fact there only seems to be one compression suggests to me that the cams were not set correctly on the front when the engine was at TDC. This however is not affirmed by the other cylinder firing and working properly.
There must be a straightforward solution to this. Is it to cycle the front cylinder 360 degrees?
 

·
Premium Member
Joined
·
7,715 Posts
Well, if you turned it by hand first it will be fine. I think your confusion comes from using front or rear.
TDC on the compression stroke cylinder 1 fires.
Counter Clockwise 285 degrees of crankshaft rotation later cylinder 2 fires (during cylinder 1's exhaust stroke). So 360 degrees minus the 75 degrees V.
435 degrees of crankshaft rotation later cylinder 1 fires (during cylinder 2's intake stroke), and the cycle starts again.

If you used the indents in the crank as your guide you cant really go wrong, well you can set the cams up so the bike fires in a 75 degree stroke but that wont hurt anything.

Think about it logically, if you "When we did this with the 360 + 75 the engine stopping bolt went literally straight in - tdc. " used the front cylinder and turned the engine CCW 360 + 75 degrees that wouldn't be TDC of cylinder 2, would it? If you started from rear cylinder 360 + 75 is correct.

The important thing for all, if your doing timing and you're not sure, plugs out and turn engine by hand slowly.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #29
Right so in a minute I will take off the the cylinder head covers and see the cams. I can move the crank to reach a tdc of say the rear cam. My expectation is of sticking down a wood dowel to guide me then find the hole in the crank for the engine bolt (rear cylinder first). How do I know if this is stroke one or three (I am guessing that the cams should be like in the manual for stroke one). From that point I go through the process of turning the engine 360 + 75 to ensure the front cylinder it where it should be, lock it with the engine bolt then check the cam locations.
 

·
Premium Member
Joined
·
7,715 Posts
Hang on, Ive got a hang over. It makes no difference, engine fires every TDC. Look in the manual for cam marks as I cant remember x or dots. TDC cylinder 1, put locking pin in, cams should have marks perfectly aligned and with flush of heads pointing furtherest away from each other.

Turn engine CCW 285 degrees until mark for locking pin TDC on cylinder 2. Repeat cam alignment.

Did you turn motor 720 degrees by hand before you hit the stater motor in recording ??????????
 

·
Registered
Joined
·
57 Posts
Discussion Starter #31
Before I tried to start it I turned it over by hand to ensure there were no contact points yes.
So, cylinder cases off and pictures to follow. First picture - rear cylinder, tdc, front cam - engine locking bolt (eb) in place.
 

Attachments

·
Registered
Joined
·
57 Posts
Discussion Starter #33
So,
Turn engine CCW 285 degrees until mark for locking pin TDC on cylinder 2. Repeat cam alignment.
This is not what I have done. I have done 435 degrees! That is a clear distinction. One of us must be wrong - and the bike is not working. The manual says:
T HE CRANKSHAFT MUST BE TURNED 1 ROTATION AND 75° IN A
COUNTERCLOCKWISE DIRECTION , OTHERWISE THE IGNITION INTERVAL WILL NOT
BE CORRECT AND THE MOTOR WILL NOT RUN .
The motor is not running.
How can 1 rotation and 75 degrees not be 435.....?
 

·
Premium Member
Joined
·
7,715 Posts
No, no and no. The manual states 360 + 75 degrees right? Ive not read it but this must be from checking the rear cylinder first, then one rotation 360 CCW to exhaust on rear cylinder plus 75 degrees to TDC on first cylinder. It physically cannot be any other way.

Your first photo shows and x and a dot on the rear cylinder cams, this is wrong. It should be either dots only on one cylinder and x's on the other cylinder, the cams are marked front and rear cylinder, don't mix them.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #35
Thank you for your help on this.
All cams were taken out with their bridges and cable tied together none were misplaced or mixed. I just checked and the cams are marked INRE and EXRE coorectly.
I have just taken more photos of the rear one. There are x's on the cams, They are very tricky to photo so I marked them on the other side of the cogs. One is on a tooth and the other is in a valley. I have checked the cylinder is indeed TDC with a large hex key and it corresponds to the eb finding its hole. These are from the rear cylinder.
I believe this is exactly right. The cams are pointing inwards. All this is exactly as per the manual.
 

Attachments

·
Premium Member
Joined
·
7,715 Posts
OK. START AT REAR cylinder, and take to TDC so marks on cams are aligned. The cams should NOT be under tension as per measuring clearances.
Rotate engine at stator nut CCW 435 degrees so FRONT cylinder is at TDC, are the marks aligned and cams not under tension?

This is exactly the same if you started from TDC FRONT cylinder, rotating CCW 285 degrees to TDC REAR cylinder.
 

·
Registered
Joined
·
57 Posts
Discussion Starter #40
Good.
But why oh why is it not running?
Spark is good, can smell petrol from rear of bike when trying to start, a spray of damp start and it not fire, compression seems good. Sounds like the timing is correct.
I am at a loss. Engines are simple aren't they? I am loosing a bit of hope with this one.
My concern was that the pulse generator cog was not put on right but if my memory serves me right there is only one way of putting it on anyway.
Is it time to take it to a garage for a professional to get their hands on it? I can't see what they could do that I cannot (except fix it!! :) )
 
21 - 40 of 61 Posts
Top