Author Topic: Re: Engine cutting out... (Read 2241 times)

RonnyBlack · « **on:** 11 November 2014, 04:45:50 pm »

New to this forum and wondered if I could get people's advice...

Just bought a 2003 FZS 600 with 44,000 on the clock as my first big bike. Test rode the bike, nothing seemed out of place and everything seemed in order. I was really impressed with the bike overall and it's power delivery.

However, from time to time, the engine now occasionally decides to cut out for a few seconds and then occasionally back-fires when restarting. I wondered if this might be a side stand switch issue but don't understand the back firing? The seller stated the bike had been left to stand outside under a cover for 2-3 months and I wonder if the switch is sticking. If it is the switch, how easy is it to replace? The bike also has an immobiliser and I wondered if it might have something to do with this?

Additionally, the bike has just started exhibiting a noticeable knocking sound coming from the engine when the bike has been running for a while and then placed in neutral. There is no knocking initially from cold in neutral only once the bike has been run for a while and warmed up. Could this be a big problem or could it be a case of flushing and balancing the carbs? Not really sure how to do this but I have got a Haynes manual that came with the bike. Would the bike benefit from draining and putting in new oil in? This has really got me worried...

Finally, the bike has a Scottoiler fitted but it's not working. It may well be blocked owing to being stood for a few months. Is there an easy way to flush/unblock the Scottoiler system that anyone knows of?

Any help/ideas would be greatly appreciated...

ChristoT · « **Reply #1 on:** 11 November 2014, 05:14:21 pm »

The cutout could be a bad connection on the spark leads - especially in the wet weather we've been having recently!

The Fazers always knock a little... just out of curiosity, what RPM do you idle at? If the bike's been sitting, a carb balance is a good plan. If you don't want to do it yourself, it's cheap enough to get a local garage to do it.

Ebme Geek · « **Reply #2 on:** 11 November 2014, 06:06:31 pm »

Yep I would be suspicious of the side stand switch, try getting some contact treatment oil/cleaner in to it and operate it loads of times, then similar engine stop switch, rh handle bar.

And the imobilizers seem more trouble than they are worth as these bikes get older, I would be looking at getting rid of that now even if it is not your problem now, before it is !!!

Others on here have had the wiring in the area of the imobilizer chafe on the fram aswell causing intermittent cut outs.

As for the knocking, when it happens does it stop if you pull the clutch in, or only if you put it in gear, clutch baskets get a little worn and then start to clatter with no load on them

Jules-C · « **Reply #3 on:** 11 November 2014, 08:06:42 pm »

The back firing is because when the engine cuts out its still pulling air and petrol through the carbs but it's not being burnt in the cylinders and the exhaust is filled with unburnt petrol vapour. Then when the engine cuts in again the hot gases set fire to the unburnt vapour in the exhaust

His Dudeness · « **Reply #4 on:** 11 November 2014, 09:05:01 pm »

Stating the obvious but if all the cylinders are cutting out it has to be something that effects all of them so like you said all of the safety cut out switches. You can bypass them one at a time by tracing them back to their connection and disconnecting them and bridge the connector with a bit of wire. Other things to check would be that the battery connectors are tight also the alarm if it has one. Does the knocking only happen at idle? Does it go away with the clutch pull in? If so it's normal and a carb balance will help. It would be a good idea to do the oil change as well as you don't know for sure how old the stuff in it is.

andybesy · « **Reply #5 on:** 11 November 2014, 09:13:18 pm »

Hi Ronny,

Welcome!

As above suggests, in respect of backfiring don't get distracted by this, if you wanted to deliberately make the bike backfire (like a hoon!) then you would (when rolling) use the kill switch to cut off the engine, while (with clutch out) letting the engine turn over so it pulls in fuel/air mixture, then when you re-enable the ignition via kill switch it will back fire. I mention this to explain why it's happening, but don't want you to get distracted by this and assume it's a fuelling issue.

Presuming it's cutting out when running, and on all four cylinders (as opposed to just loosing power, or bogging down, or dropping one cylinder) then it's likely an ignition problem. Perhaps due to water getting in somewhere, electrical short, or similar. Can't tell you of top of head what the cause is, you'll need to go through logical process to diagnose and there are others more expert than I who can assist with this, but did want to reassure you that it's not massive worry, once sorted should be fine.

A good thing to start with would be WD40 on electrical areas such as HT leads etc as that should help displace any water. Also check the drain holes around the head/cylinder are not blocked as these are used to drain water from around the spark plug area.

The side stand is a simple mechanical switch operated by a plunger. Don't be scared to get down and have a close look near where the sidestand meets the frame. If it's all gunked up then certainly when you raise the side stand the plunger can fail to move and the bike can fail to start. But unless there is something wrong with it internally/electrically I wouldn't expect this to affect you when up and running, only when on the drive. None the less go-ahead and give it a good clean, can't hurt. Soap and water or degreaser, then some WD40 or similar to lube.

So to confirm, it's cutting out when running, or failing to start on the drive?

Now putting that all to one side, this knocking, how bad is it, and does it go away with clutch pulled in? They are a bit grabby and so do rattle a little in neutral with clutch out, although in my experience usually more when cold than hot. Any chance of a video?

Andy

RonnyBlack · « **Reply #6 on:** 12 November 2014, 12:01:23 am »

Hey Fellas... Thank you for all your responses...

To confirm, 99% of the time the bike/engine runs really sweet. Then occasionally, whilst riding, the engine completely cuts out/dies for a few seconds. With the ignition still switched on, firing the engine usually kicks it back in (still whilst in motion) and all is well once again. Just found it disconcerting and more than a little bit dangerous especially considering this is my first big bike. Will check the spark leads and confirm idle RPM ChristoT. - Will do [/size]Ebme Geek but was hoping to keep immobiliser if possible. Will check the immobiliser wiring though. Again, will check the clutch in / knocking sound tomorrow. - Thanks for the explanation [/size]Jules-C. Really helps to understand why the back firing occurs. Sounded like a missile attack first time it did it and I very nearly "papped" my pants... Thought this would probably only happen from riding the bike itself and not from an unexpected back-fire...

- Will definitely check out all safety cut out switches, battery and alarm connectors. Will give the bike an oil change as a matter of priority [/size]His Dudeness. - Again, [/size]andybesy thanks for the info reference backfiring. Yes, it does cut out when running. Will get the WD40 out and check for any blockages. Like you say, a clean and WD40 on the side stand can't harm. Will confirm the knocking sound/clutch in situation tomorrow.
[/size]
[/size]Again, thanks for all your suggestions. Feeling more re-assured at this stage. By the way... what a great bike... When the engine doesn't cut out (i.e.. 99.9% of the time) it performs ever so sweetly and at 7,000rpm, goes like a bullet. Doesn't feel twitchy on the front end at all and the more I ride the bike, the more confidence the bike gives me [/size]([/size]not over confidence mind...) and the more I love it...

RonnyBlack · « **Reply #7 on:** 14 November 2014, 06:39:42 pm »

By way of an update...

Knocking sound coming from engine appears to be more of a clattering sound and is not as prominent when clutch is engaged. Is this relatively normal? Does this indicate a problem with the bike?

Will be going through all checks tomorrow in order to isolate the cutting out issue.

Regards Fellas...

andybesy · « **Reply #8 on:** 24 November 2014, 05:02:43 pm »

Hi Ronny,

Sorry for delay replying.

It's difficult to say about the sound you're reporting without hearing it. Why not make a short video with your phone and then share it to YouTube and let us know the link.

Bur speaking in general terms, it's normal to have a bit of a noise in neutral when the clutch is not held in, because the clutch is a bit grabby. If it goes away when the clutch is pulled in then it's probably nothing to worry about. That having been said I would generally expect this to be more noticeable with a cold engine because cold oil is thicker and so uncertain if this is what you're reporting.

Andy

john 087 · « **Reply #9 on:** 30 November 2014, 07:18:44 pm »

My own does that an odd time, mine is down to ign switch witch is probable worn at this stage, keep meaning to replace it, I keep spraying contact cleaner every couple of weeks and it still keeps going.