How do my sparkplugs look to you?

[Steam]

How do my sparkplugs look to you? Okay?
I often hit a flat spot at 100kph and I wonder if it has anything to do with my plugs. The spark gaps seem to be more than the 0.6 to 0.7mm specified, so maybe I should bend the thingies down a bit.

I got the carbs cleaned and inspected already, so the problem's not there.
Hmmmm....

[Pwalo]

Big fella, your spark plugs look ok. It's a bit hard to tell in the photo's but they seem to be a nice light brown/grey colour, as they should.

I'd pick that your problem lies with your carburetion. It's not your speed that you need to note, but what sort of throttle opening your flat spot is occuring. This will let you know which jet you need to have a look at. If it's on a closed or just open throttle it's probably your pilots, etc.

Have you got a manual?

Suggest that you have a search for carburettors, and their workings on the inter web. I'm afraid it's an arcane process.

[Steam]

I'd pick that your problem lies with your carburetion.

Thanks for the plug assessment Paul. I concur.
As for the carbs, oh dear, I just got Motormart (Petone) to inspect and clean them, and they said they were ok and just cleaned out some gunk... Maybe they missed something.
It only happens when the throttles are wide open, to the max.

Argg, maybe I should just bite the bullet and take it to Motorrad, get them to fix it proper-like.
Dammit I hate being poor.

[limbimtimwim]

Well, they'll make you poor.

So, you have the throttle wide open and the bike is accelerating fine, then you hit 100km/h and a coughs and splutters a bit, and then it roars off again at like 110?

Oh and ahh, how many revs are you doing at the problem point and where does the redline begin?

[bistard]

I know you wont have a rev counter,but does it missfire at the same revs in each gear??
next question,whats the condition of the air filter.is it dirty/blocked??
If it only missfires at 100kph,it sounds like maybe a jetting problem & cleaning the carbs wont help,you will need to replace the main jet
My suggestion would be to get a mechanic to experience the problem & advise you

[Pancakes]

I had a PDF saved that showed plugs and that the colours etc mean, will liik for it and post it up if I find it. To test you need to run through a gear (3rd?) and then without engine braking or idling killit and into neutral, roll back to your garage and whip them out.

Hey tech people; How hard would it be to install and program injectors? I guess it's who you know (dyno, starting maps etc) and who much time is on your hands if it is going to be cheaper than buying a new bike? Would it be cheaper than a full carb strip, tune and dyno?

[Scouse]

Do you mean " do my spark plugs look big in this"

[Storm]

Thats a pretty personal sort of a question to ask. Big ups to you for being brave enough to ask it:D

Seriously, the plugs look fine to me- I'd look at running some welders cleaning tips/a strong jet of compressed air through all your jets, and checking/cleaning your airbox-filter-snorkel-carbs pathway. Wipe the grime off the rubber etc. Just follow the path from tank/airbox to combustion chamber and clean it all thoroughly.
Hope that helps :D

[Steam]

So, you have the throttle wide open and the bike is accelerating fine, then you hit 100km/h and a coughs and splutters a bit, and then it roars off again at like 110?
Hey! like that! But sometimes I can't get through that 100kph barrier, so I'm stuck there.


Oh and ahh, how many revs are you doing at the problem point and where does the redline begin?

6500 rpm is where it happens, redline at 9600 rpm.

...does it missfire at the same revs in each gear??
Yes that's right, at about 6500 rpm in both 5th and 4th gears.


next question,whats the condition of the air filter?

Clean as a whistle.

Thanks for your suggestions folks.

[paturoa]

What are the points like (assuming not cdi?) and the advance / retard mechanism?

[Steam]

Thanks for your suggestions guys.

I've also asked on the CX500 forum in Australia and they said immediately "classic stator failure".
Now, on a CX replacing the stator means TAKING OUT THE ENGINE and splitting it open. The stator's right inside. WHO DECIDED THAT I ask you. AARG!
First I have to test voltages and resistances, etc, to confirm it.

Still, it does give me something to do for the next few weeks, between split shifts at work.

[dangerous]

Thanks for your suggestions guys.

I've also asked on the CX500 forum in Australia and they said immediately "classic stator failure".
Now, on a CX replacing the stator means TAKING OUT THE ENGINE and splitting it open. The stator's right inside. WHO DECIDED THAT I ask you. AARG!
First I have to test voltages and resistances, etc, to confirm it.

Still, it does give me something to do for the next few weeks, between split shifts at work.

No worries man, i had it down packed between two of us from running, too on the bench... in 20mins.

Bloody water pump in my case every time.