Author Topic: Carb problems I think? (Read 5786 times)

GILBERT · « **on:** 13 April 2012, 06:50:56 pm »

Hi all,

Been out this afternoon & on the way back I opened the bike up on the bypass, came to the roundabout and the bike felt rough & sounded like a Subaru (honestly). Limped home the last couple of miles with the bike being rough at low revs - but still idling at the lights etc. I am automatically assuming that one of the jets has picked up something & is now blocked.

Back home the bike will idle ok - albeit roughly, but when I ride it down the lane it lurches forward at times, so the required u turn become I bit dicey.

I have balanced the carbs & they are equal but cylinder 1 is a little eratic.

Can any one confirm that the problem sounds like a blocked jet as I never taken a carburettor apart, or could it be something else.

Is checking & cleaning

[size=78%] the jets difficult?[/size]

Cheers all.

sadlonelygit · « **Reply #1 on:** 13 April 2012, 07:16:56 pm »

sorting out the jets is easy...........taking the carbs off, well that's a different matter.

however........if you have put a balancer on the carbs and no1 is erratic, then probably not your jetting as it measures your engines airflow.
worst case scenario.......dropped valve
best case scenario........perished manifold/loose connection/crap trapped under the seat

silly Q but all the plugs are tight.

good luck

mcyoungy · « **Reply #2 on:** 13 April 2012, 07:18:57 pm »

I had similar last week with the carb balance and it seems to have been a plug cap poorly connected to the lead........ it came off in my hand! snipped off the last quarter inch of lead, refitted the cap tightly and all sorted.

Phil TK · « **Reply #3 on:** 13 April 2012, 07:54:38 pm »

Are you sure the airbox intake trumpet hasn't been partially blocked by a rag or some other object you might have put under the seat?

GILBERT · « **Reply #4 on:** 13 April 2012, 08:17:01 pm »

Just checked the plugs and they are in good nik & nice n' tight.

The bike has done 17k & i have owned it from new.....2004. The bike feels ok at higher revs its below 3000 thats its noticable & walking pace involved a lot of clutch slip to raise the revs.

Don't think it could be the HT coils do you?

GILBERT · « **Reply #5 on:** 13 April 2012, 08:18:42 pm »

I'll check the airbox tomorrow

Lets hope I don't find any mice in there!!!!

mcyoungy · « **Reply #6 on:** 13 April 2012, 09:24:35 pm »

Quote from: GILBERT on 13 April 2012, 08:17:01 pm

Just checked the plugs and they are in good nik & nice n' tight.

The bike has done 17k & i have owned it from new.....2004. The bike feels ok at higher revs its below 3000 thats its noticable & walking pace involved a lot of clutch slip to raise the revs.

Don't think it could be the HT coils do you?

exactly the symptoms I had.

tomlinscote · « **Reply #7 on:** 13 April 2012, 09:36:02 pm »

I had the same thing, I took took plugs out all looked ok, still shite below 3000 or so but fine above that.
Changed plugs and air filter ran like a dream since then, maybe worth a try esp if plugs not been changed for a while.

P

Falcon 269 · « **Reply #8 on:** 13 April 2012, 10:20:59 pm »

You didn't say clearly whether you'd checked the plug leads and made sure you have a good contact between lead and plug cap. Not the same as making sure the plugs are tight and the caps secure on the plugs.

From your description, it's misfiring on one cylinder. I don't think it's a carb issue from what you've said. HT coils seldom fail on these bikes so first call should be to revisit the plug caps etc etc.

GILBERT · « **Reply #9 on:** 14 April 2012, 12:28:46 pm »

One thing I forgot to mention before that may have a bearing on my problem is that for some time now when I turn the ignition on there is an electrical crackling sound, a bit like frying bacon. The crackling fades in around ten seconds.
Anybody now what this could be as I have been having this for a couple of years now, as it does not effect the running of the bike I have ignored it.
Could this be a HT lead issue?

GILBERT · « **Reply #10 on:** 14 April 2012, 12:35:28 pm »

I have checked the air filter & area around and its all clear & clean. Will check the plug leads this afternoon & trim the ends as mentioned.

When I balanced the carbs yesterday I mentioned that cylinder 1 was a little erratic, the vacuum gauge on no.1 inlet was dipping every 5-10 seconds or so - the dipping was at quite regular intervals, there was also a audable click when this dip happened. Having started the bike up today the same dip is there when the bikes idling with the bike not settling at a regular idle, but 'hunting' between 1,000 & 1,300 rpm.

Falcon 269 · « **Reply #11 on:** 14 April 2012, 01:05:47 pm »

The crackling noise is the EXUP servo motor. Not unusual and not the cause of your problem.

The 'click' to which you refer could be the spark shorting to earth.

GILBERT · « **Reply #12 on:** 14 April 2012, 06:10:43 pm »

I have trimmed the plug caps & removed & inspected the cap internals, everything looks o.k. & all the plugs fit tight with that serrated grip you can feel when pressed home.

Bike still running rough

I think the next thing will have to be the change the spark plugs, although plugs appear externally in good condition, then possibly change the HT leads (could this be the problem).

I am going to put off removing the carbs apart until its the last resort. The bike is completely standard except from a Blue Flame tail pipe.

If it is the carbs, then the Haynes manual says that all seals & gaskets need to be replaced in the carbs. Is this absolutely neccesary?

With regard to the sissling that I hear when the ignition is switched on, it is coming from the ignition (key area).

Just want my smooth Fazer back.

Thanks for all your advise & help.

mcyoungy · « **Reply #13 on:** 14 April 2012, 06:31:01 pm »

try running some fuel system cleaner through the bike. I use Silkolene Pro-FST...... there are others.

Timbo · « **Reply #14 on:** 14 April 2012, 09:09:09 pm »

If you have a crackling sound eminating from around anything relating to the electrics it tends to suggest something is not healthy!! Check and double check the connections around the ignition switch, but bear in mind that if something has failed internally it may well make poor contact which will produce the crackling noise and could , if in a related circuit, be the cause of all your woes.

When electric curent passes thru a circuit the wiggly worms do it very quietly so there should be any noise at all! They don't smell and you can't see them.....although they do bite occasionally and the very fierce ones do hum to themselves!!

tomlinscote · « **Reply #15 on:** 14 April 2012, 09:42:41 pm »

Mine, like a great many others does the same the same thing, it is the EXUP servo doing its re-aligning thing, just as Mike said, and its never been a problem. Thought about watching the Grand National but as it wasn't raining here took the bike for a 90 nile run to local DIY shop much more fun in my opinion!

james43 · « **Reply #16 on:** 14 April 2012, 11:12:29 pm »

Get it Ivanised, problem solved.

The Male Whale · « **Reply #17 on:** 15 April 2012, 09:25:44 am »

Quote from: james43 on 14 April 2012, 11:12:29 pm

Get it Ivanised, problem solved.

Not unless Mike is now fitting plugs as well as the Ivans kit.....

Could be carbs, could be sparks. We are yet to establish the problem so are probably not ready to throw a good solution at a random problem..

Ivans is a great mod but it may not cure this issue same as it wouldn't cure a flat tyre.

However, your considered advice is very welcome!

Whale

GILBERT · « **Reply #18 on:** 17 April 2012, 02:49:47 pm »

Panic over.....

New spark plugs arrived today, just fitted them & the bike is healthy again.

I have had a couple of sleepness nights worrying about taking the carbs off.

With regard to the crackling/sizzling from what I thought was the ignition is in fact coming from the exup servo motor (You were right Mike). Still sounds like a unhealthy electrical sizziling to me though.

Thanks for all you help everyone.

Falcon 269 · « **Reply #19 on:** 17 April 2012, 06:24:08 pm »

Good, sorted!

Don't sweat the EXUP servo, I've heard dozens do that and failure are very very rare.