Hi all. Hope you are well. I have been a silent viewer of this site for quite a while. Bought my f3 in 2013 and rode for the summer until an incident with a loose chain force me to get taken home on the back of a trailer in late November . Since then the bike has been off the road due to starting to do some cosmetic work to it then running out of money. Since then have run into a couple of issues. 1 being a dead datatype alarm which was preventing the bike from starting, all removed and the bike is starting again, Chinese plastics that should have fit straight on modified to fit and a few minor additions such as led indicators and rear lights, braided brake lights etc.

Unfortunately I have now found a final issue that has me stumped. The bike although starting every time on the button with a touch of choke when cold does not seem to be running right. Idle seems to surge if I can get it down to about 1.3k if I slam the throttle open from here the bike wants to die. Also took it for a small spin in my cul de sac, and there seemed to be a hesitation around 5k on first gear.

I'm looking to do the ram air system removal (think that's what it's been called... The slow circuit)

But think I have found that the clutch side cylinder is not working (header isn't evaporating water when sprayed onto it) I have replaced the spark plug to no avail and was wandering where people would suggest to look next. Also the carbs were cleaned and put back on the bike only 2 weeks ago. although i have not done this myself before.

Sorry if the post is long just thought it polite to introduce myself and give as much info as I could.

Thanks in advance for any help.

 

Sounds like you have a dead cylinder.

Each cylinder needs 3 things:
Fuel.... And in the correct amount
Spark.... And in the right time
Compression

Figure out what you're missing and you got it.

You put in a new plug, what do the old one look like? Old plugs tell stories of what in going on with the burn.

Does it spark?
Is the dead cylinder getting fuel? Or too much fuel?
Compression and motor parts just don't go bad without a good story... Unless you have one, you're probably ok. Wouldn't hurt to give it a check if everything else checks out.

 

Thanks for the rapid reply 74demon

I've attached the photo of the old plug. Im not very knowledgeable on this, but from what Id expect it doesn't seem overly burnt.

How would I check spark? - I assume I'd have to take the spark plug put attach to the ht lead - do I need to ground the plug against the engine case?

How would I check fuel at the cylinder?


**EDIT***

looking at the photo, it appears darker than it looks in real life. much closer to what ive seen from burnt plugs on the net so im not hugely sure, would a burned plug indicate a lean environment. if i also said the bike used to backfire on deceleration when i was riding it back in 2013 would that give any potential clues. Thanks again

 

Plug appears that it was getting fuel. Pull the new one out and compare it to one of the other new ones.

To check for spark, ground the plug to anything metal on the engine and crank it over or start it. Valve cover bolts work well....

Be careful, that spark will get your attention if it grounds through you!

 

OK so the old and new plugs have spark, attached a photo of the new one. Only bought the one plug to replace the one in the cylinder as it wasn't firing. So the other plugs are old.

Can smell the fuel on the plug that I have just taken out as well.

I'm at a bit of a loss here. But wandering if it ever had all cylinders working. As I do remember it wanting to die at times previously but put it down to being cold. Then I'd get straight onto the motorway from where I was and with it being my first bike I don't really have anything to compare it to.

 

OK so a bit more news. Don't know if it's good or bad. So I just took the bike for a tiny spin round the area where I live. Long story short the bike feels like it did before.

So good spin is that it seems to be working as well as it has ever been, bad news is that it's still definitely a cylinder down.

Question for anyone in the UK or that knows our road laws. Will having 1 cylinder down prevent me from getting it an MOT certificate?

And with spark and fuel where is my next port of call? Presumably it can't be the coils.

When riding I get a definite surge of power at what I'd guess is about 5-6000 rpm. I didn't look when riding and considering I'm not far from the police station didn't wanna risk getting in trouble. Could that potentially suggest a blocked pilot jet? Is there a way to try and clear that without stripping the bike down again to get the carbs out?

And just for fun, here she is. The grubby little mare. Need to get her MOTd so I can take her home and clean her. She's stored in a garage away from the house with no utilities at all.

 

You have spark, so you can rule that out provided that the plug wires are going to the correct place.

You have fuel, or it wouldn't be wet. It could be that something is off with that carb.
Who cleaned them?

I would be checking compression next. If you don't have access to a compression gauge, you will need to take it to someone that does.

 

OK the bug got me and I snuck her out for a bit of a longer run. Once she's going she seems to pull well, so not really sure what's going on. But definitely sounds rough and backfires if I rev her hard. Just trying to upload her idling and revving to YouTube. Hopefully that will give some more insight.

I cleaned them myself taking my time and following instructions from here, YouTube and a friend. But may be the cause still. So from what you say looking like carburettor or compression are the next calls. Thanks again.

 

Did you sync them after they were installed?

 

No been researching on how to do that I'm honest. Would that cause 1 cylinder to not fire?