K100 running rough - video

[Ogmios]

Right you lot.
Though i am being guided by St. Farkoff of the North in the care and feeding of the beast - i submit for your piss taking, a wee video of the offender. (the Bike - not The Good Doctor)
I am at my wits end (admittedly this is not a long journey )

So, you tell me wtf is wrong with this Bike.

EDIT: it's me doing the revving up of Bike from 1.35 on.

<iframe width="640" height="360" src="//www.youtube.com/embed/VLRMSk_Fyl0?list=UUmMSgyyMbdbMtIQPVz5q2yw" frameborder="0" allowfullscreen></iframe>

 

[bumpmuncher]

missfire change the plugs then the leads then if it is still doing it try the coils ( that is what I would do after a WOT run, but seeing as i am not a grown up it is probably best to wait for a propper reply from someone what knows K's)

 

[Ogmios]

So far i've ...

Cleaned out the tank.
New plugs.
checked fuel pump.
new fuel filter. (old was trying to implode )
checked spray pattern of injectors (neat triangular spray)
it is still an alcoholic.
er....
and wotever else Jay told me.
( i know ___K all!)

~~
(petrol) fuming here.

 

[Ian Whinnett]

There seems to be a clonking noise in the background? When I started to get that noise it turned out to be the rubber Cush inserts on the output shaft. Normally it starts to clonk on start up only but I have heard one that had been left to get much worse and that to ran like a bag of nails and sounded awful. If it is left to long it is pretty much doom for the engine. Mine was a high mileage 1983 bike so I got a later second hand unit from sherlocks. Got a low mileage late model unit for about the £400 mark, he had units there for much less. Mr Steptoe is the fount of all k knowledge and it may be worth asking him as I have only limited experience.

As I understand it the rubbers wear and allow the shaft to have an adverse affect on the smooth running of the engine, thus giving symptoms like a misfire.

Hope this helps.

Ps it is not a cheap option to repair buy the time all the other bits have been purchased. My replacement engine came with a gearbox, starter, alternator and a pair of coils.

 

[(RIP) Kaister]

fuel pressure regulator ?
stiff or sticking air metering flap in the LE Jetronic air mass sensor box ?
air leak at the throttle bodies ?
temperature sensor on the fluid stub (behind the radiator )
air temp sensor ( its a small thermistor on the inlet of the afm (inside the top cover of the air box )) could be dirty ?
air breather between the plenum and the engine crankcase (only about 18mm thick tube but odd angles ) ...often get cracked and need replacement ...the motor idles like crap with this fault

 

[DrFarkoff]

Yup my thoughts lay to that direction either that or the engine thinks it's -20 degrees (coolant sensor failure)

Known good ECU has been fitted with no change

1 number 3 lead set aside for transportation
Coolant sensor
and a fuel pressure regulator

fuel pressure regulator ?
stiff or sticking air metering flap in the LE Jetronic air mass sensor box ?
defective temperature sensor.?

 

[Ogmios]

Ian,
i so hope you're wrong! but thanks anyway.

Kaister,
fuel pressure regulator ?
to be checked.
stiff or sticking air metering flap in the LE Jetronic air mass sensor box ?
no - been in there - it's o.k.
air leak at the throttle bodies ?
no.
temperature sensor on the fluid stub (behind the radiator )
to be checked.
air temp sensor ( its a small thermistor on the inlet of the afm (inside the top cover of the air box )) could be dirty ?
checked - clean.
air breather between the plenum and the engine crankcase (only about 18mm thick tube but odd angles ) ...often get cracked and need replacement ...the motor idles like crap with this fault
i had hoped it was this.... it aint now - i've duck taped it til i get a new one, it looks rough but functions.

Ta for the ideas.
Dr. F has given me lots of 'homework'.
i'll report back.
New 'o' rings for injectors just arrived - two that are on the Bike are pretty rough, so no harm in changing these anyway.

 

[Fanum]

There seems to be a clonking noise in the background? When I started to get that noise it turned out to be the rubber Cush inserts on the output shaft. Normally it starts to clonk on start up only but I have heard one that had been left to get much worse and that to ran like a bag of nails and sounded awful. If it is left to long it is pretty much doom for the engine. Mine was a high mileage 1983 bike so I got a later second hand unit from sherlocks. Got a low mileage late model unit for about the £400 mark, he had units there for much less. Mr Steptoe is the fount of all k knowledge and it may be worth asking him as I have only limited experience.

As I understand it the rubbers wear and allow the shaft to have an adverse affect on the smooth running of the engine, thus giving symptoms like a misfire.

Hope this helps.

Ps it is not a cheap option to repair buy the time all the other bits have been purchased. My replacement engine came with a gearbox, starter, alternator and a pair of coils.

Shirley this wouldn't affect tickover in neutral though?

 

[DrFarkoff]

Dr. F has given me lots of 'homework'.
i'll report back.

Right you have had all night Homework is now due!

 

[Ian Whinnett]

Shirley this wouldn't affect tickover in neutral though?

I refer to the first part of the comment made by Steptoe from the following thread. http://www.ukgser.com/forums/showthread.php?t=95757 this was exactly the symptoms I had and soon enough the words of Steptoe sank in and I decided to do something about it before terminal destruction occurred. I did try and repair the engine but the damage to the drive gear of the crankshaft was excessive and it turned out to be cheaper to get a second hand engine. Unfortunately I found out about the crank wear by rebuilding the original unit and discovering it still knocked.