running lumpy

[darrenc]

Hey foccers, need a little advice, started the bike and its running lumpy as shit (sounds like its only running on 3 cylinders) once warmed up it runs OK and sounds OK. However only 3 of the four header pipes seem to be getting hot. The one on the right in the picture doesn't get anywhere near as hot. Would a new set of plugs sort this?

[red98]

How old and how many miles on the plugs ?

[darrenc]

Bike has only done 13k but previous owner never used it so its been sat a long time, not sure how old the plugs are.

[acid drop]

try swapping two plugs over and if the cold header warms up it will point to a faulty plug.

[darrsi]

Make sure you clear the area around the spark plugs of any debris, leaves, dirt, etc, to avoid anything dropping into the pistons.

[mtread]

Also make sure the plug cap is on properly ! 

[Jules-C]

Running on three at start/idle can be sign of carbs needing balanced but once moving all 4 should get hot

[YamFazFan]

When mine ran similar to this it was a blocked pilot jet in one of the carbs that was the culprit.

[darrenc]

Well just been out for a 30 min ride, and same still happening, noticeable a lot more when bike first starts however bike still seemed hesitant throughout the ride. When I got home I quickly felt the headers and the first was although warm was nowhere near as hit as the rest. I'm gonna have to bite the bullet I think and get it to the garage for new plugs and a carb balance as the last bloke I bought it off had clearly left the poor thing sat there for months on end without rising it.

[CaptainCazador]

Good luck with removing all 4 plugs without one snapping off in the head.


When I bought my FZS it had also been sat for years unused the plugs had never been changed long story short one of them snapped despite blasting them with plusgas everyday a week prior to extraction (suggest you do the same whether you take it to a garage or DIY). Head had to come off to remove the remnants of the snapped plug. That was fun.

[Fazerider]

When mine ran similar to this it was a blocked pilot jet in one of the carbs that was the culprit.

:agree 
Agreed. On a bike that's been standing ages there's a good chance the carbs are in need of a clean.
If cylinder 1 isn't firing just balancing the carbs won't help.
Firstly though, you could try trimming 8mm off the plug lead and screwing that back into the plug cap... the lead end breaking up causes at least 50% of rough-running faults on the Fazer.

[darrenc]

All these possible solutins I have read a lot of other posts on here as well suggesting it might be a blocked jet. In higher revs, I.e above 5000rpm it seems a lot less noticeable. When the bike is cold and at lower revs its like a tractor. The first header pipe gets warm but not unbearably hot to touch so does that indicate a knackered plug or could it be a carb issues for that cylinder? I don't want to get ripped off at the garage either. And here's me thinking I was in for some trouble free biking, had nothing but issued with the foccer and haven't even started using it for commuting yet

[Frosties]

Might be worth triple dosing this in a tank and riding it hard - works for me


http://www.halfords.com/motoring/engine-...trol-400ml

[YamFazFan]

In higher revs, I.e above 5000rpm it seems a lot less noticeable. When the bike is cold and at lower revs its like a tractor. The first header pipe gets warm but not unbearably hot to touch

Yep that's just how my Fazer was running.

Once I got past approx. 5000rpm it pulled like a train as per usual, but was lumpy and hesitant again below that figure and also on start-up.

Down pipe number 3 was noticeably cooler after a ride and that was where the problem lay, with carb number 3.

The garage did an ultrasonic clean of the carbs and it felt like a new bike afterwards

Apparently the issue was caused by degraded/stale fuel mucking the carb/s up.

I did try a fuel system cleaner additive prior to the carb removal but it made no difference, although I used a Motul product and not the STP one which Frosties, darrsi and others on here have reported good results with.

[darrenc]

OK the STP is on offer at halfords, I have a full tank of fuel, should I stick the full bottle in?

[darrsi]

OK the STP is on offer at halfords, I have a full tank of fuel, should I stick the full bottle in?

Yep  :thumbup

[His Dudeness]

arcing from plug caps will also cause those symptoms

[darrsi]

STP Complete Fuel System Cleaner is 50% off in store at Halfords.

[darrenc]

Despite their online catalog saying there was one in stock there was Nome left so settled for this (see attached pic) stuck full lot and and blasted the foccer down the motorway (within legal limits of course officer) after one hour of tootling about its made no difference, jumped of the bike and touched the dirty foccers pipe number 1 and  still not red hot likenits 3 sisters next to her. I'm really hoping just a fucked plug or dirty corresponding carb is the issue, I can live with that. Also whilst the urbano tucano muffs kept my hands toasty as fuck I just can't get on with them so if anyone wants a pair they can have them for £25, they cost me £45 Inc postage just 2 days ago.

[darrsi]

Too late now but i've only ever recommended the STP Complete System Cleaner before because it's tried and tested by a few of us on here and does do a good job.
Which is why it's more expensive than the others.


Just something to point out as well, if you're considering a carb balance you will need:


Good plugs, and as mentioned cut 5-10mm off the end of the HT leads then screw the caps back into fresh wire.
Good fuel, i don't know where the bike's been sitting but you need to make sure there's no moisture in the tank.
A clean air filter, if you're not sure then change it anyway, but don't buy the cheapest one you can find on Ebay, 'cos it'll probably be crap. I would always recommend a K&N which are a bit more expensive but it'll be the last one you need to buy for the bike, and the feel of the bike will improve.
Do a quick TPS check and make sure that's all correct and in the right position.
And as i think you're finding out, you may have a blockage in your carbs so ideally they will need cleaning too.


If any of these things are not quite right then it can give a false reading on a carb balance as i have found out myself before.