Stutter and violent vibrations - Cylinder 2 and 4 not firing up

[ozanec123]

So I bought a Fazer today 2001 model, that was apparently kept in very good condition and with all services done on it from professional workshops. However the moment i got on it, i noticed it stutters and bogs down, basically little to no power below 4k rpm ( I guess not so uncommon).
I decided to ride a bit on high rpms until i get home, but then i was met with very violent vibrations. So what could be wrong? The owner told me he recently changed the spar plugs but that was probably triggered by something too, so it either aggreviated the problem or it didnt have any impact.
I would be really glad if you provide me with a list of possible solutions.
The symptoms and noise is very similar to these two videos


https://youtu.be/WFV4m4xzi8o

https://youtu.be/_yywJhcy9x8

[darrsi]

Was just reading the stuff that you've done to it on YouTube.
Bike sounds very rough tbh.


No mention of checking the TPS though? Wondering if you've balanced the carbs with a dud TPS and it's made things even worse.
Add to that, you also mention carb #3 may not be adjusted properly either via the screw?
It can all add up to a bad scenario like you have.


Great videos by the way, extremely helpful to get a real idea at what's going on.

[ozanec123]

The videos arent mine but thats exactly how it feels and sounds. I am clueless what to do next, because i need to travel soon but the bike is uncomfortable to drive even for 2 km.

[darrsi]

The videos arent mine but thats exactly how it feels and sounds. I am clueless what to do next, because i need to travel soon but the bike is uncomfortable to drive even for 2 km.

As above, do a quick TPS check.

[darrsi]

Look at the large box in blue above the last comment at the bottom.
Remember, you only want to check the TPS for now, don't go adjusting it as you'll need to sort out #3 carb first.


https://foc-u.co.uk/index.php?topic=25856.msg319116#msg319116

[darrsi]

.

[ozanec123]

I readjusted the TPS, got it to 5000 rpm , and i started the engine again. I could notice some 10% improvement but the problems are still all there. The engine is running very rough, jitters and vibrates

[unfazed]

Check the downpipes to see if one or two  are no getting hot. That sounds like it's not running on all four

[ozanec123]

Check the downpipes to see if one or two  are no getting hot. That sounds like it's not running on all four

Ok that was very good idea. So i just checked the pipes, and 2 and 4 arent getting hot. Does that mean 2 cylinders arent firing up at all? And if thats the case then is it the spark plugs the culprit or something else? Thanks a lot again

[unfazed]

Changing the spark plugs would do any harm just to rule them out.
However 2 and 4 would probably be a carburettor  problem rather than coil or spark plug as 1&4 share the same coil and 2&3 share the same coil
Was the bike left unused for a long time?

[darrsi]

I readjusted the TPS, got it to 5000 rpm , and i started the engine again. I could notice some 10% improvement but the problems are still all there. The engine is running very rough, jitters and vibrates

When you say you readjusted it, what did you readjust it from?

[ozanec123]

Changing the spark plugs would do any harm just to rule them out.
However 2 and 4 would probably be a carburettor  problem rather than coil or spark plug as 1&4 share the same coil and 2&3 share the same coil
Was the bike left unused for a long time?

Wouldnt say unused very long time, just few weeks probably, and kept in the garage, so no idea how could that impact it. The carbs have been cleaner recently too, though not sure if everything was done correctly there.

[unfazed]

Before you go any further just check if the plug caps are on the right plugs.

It is possible the two on the left or the two on the right were mixed up.
There should be a label number on each lead  1 on the outside on the left and 4 on the outside on the right.

Left and right as you sit on the bike when sitting on the bike

[ozanec123]

Before you go any further just check if the plug caps are on the right plugs.

It is possible the two on the left or the two on the right were mixed up.
There should be a label number on each lead  1 on the outside on the left and 4 on the outside on the right.

Left and right as you sit on the bike when sitting on the bike

No luck there. They seem to be in the right order.

[unfazed]

If the carbs were off it is possible the rubbers front and back were not put on properly you need to check them especially the two with the issue.
If they are all on correctly check that all the vacuum take off caps are on properly between the engine and the carbs

Open the drain screws on 2 and 4 and let the fuel flow out.
Turn the kill switch to off and switch on the ignition. Now watch the fuel flow from the drains when you switch in the kill switch, you will hear the pump clicking. If fuel flows from both then the fuel is getting to the bowls. Turn of the kill switch and close the drain screws. If it only comes from one the close the drain screw on it .Now turn on the kill switch again check the flow from the one that wasn't flowing. If it flows then turn off the kill switch and close the drain screw. Turn on the kill switchTurn the ignition on and off until the pump stops clicking when indicates the bowls are full

Remember the pump times out after a short while and the ignition needs to be switch on and off the reset it.
Start the bike and see it the issue remains

[BBROWN1664]

Check the leads are on teh correct plugs. From the left hand coil they should go to plug 1&4. From the right hand coil, to plug 2&3.


Sounds like he plugged them back incorrectly after fitting new plugs.

[ozanec123]

Check the leads are on teh correct plugs. From the left hand coil they should go to plug 1&4. From the right hand coil, to plug 2&3.


Sounds like he plugged them back incorrectly after fitting new plugs.

Checked that and based on the labels they are in right order

[ozanec123]

If the carbs were off it is possible the rubbers front and back were not put on properly you need to check them especially the two with the issue.
If they are all on correctly check that all the vacuum take off caps are on properly between the engine and the carbs

Open the drain screws on 2 and 4 and let the fuel flow out.
Turn the kill switch to off and switch on the ignition. Now watch the fuel flow from the drains when you switch in the kill switch, you will hear the pump clicking. If fuel flows from both then the fuel is getting to the bowls. Turn of the kill switch and close the drain screws. If it only comes from one the close the drain screw on it .Now turn on the kill switch again check the flow from the one that wasn't flowing. If it flows then turn off the kill switch and close the drain screw. Turn on the kill switchTurn the ignition on and off until the pump stops clicking when indicates the bowls are full

Remember the pump times out after a short while and the ignition needs to be switch on and off the reset it.
Start the bike and see it the issue remains

Looks very complicated for me , who hasnt done any mechanical work. Ofc I can go to a mechanics, but that would cost half of the bike already.
Any youtube  video done on similar bike that I can follow along? I apologise for the endless requests, i just need to ride soon for my holiday and this issue is driving me crazy now.

[BBROWN1664]

Check the leads are on teh correct plugs. From the left hand coil they should go to plug 1&4. From the right hand coil, to plug 2&3.


Sounds like he plugged them back incorrectly after fitting new plugs.

Checked that and based on the labels they are in right order

Dont go by labels, they may have been put on incorrectly. Did you check that the HP leads for #1 & 4 went to the same coil?