Motorcycle ACTS running lean, but LOOKS like running rich?

[G-Sizzle]

I have a Kawasaki w650, its and 02 model with 45,000 miles on it of which I have done approximately 240. Since I bought it has had some problems running, and I’ve tried to get to the causes of it but I am having trouble. Lets start with the problems/symptoms:
1. When starting the motorcycle:
- it needs a long time (5 mins) to warm up even in warmer weather, on full choke.
- it does not idle, and the revs like to move up and down (+ and – a 1000 revs)#
- but it does NOT stall when given throttle, just has a sluggish response.

(cleaning the spark plugs, air box and filters, carbs are clean has improved these symptoms but I’m still getting carbon fouling on the plugs just warming it up again)

2. When riding the motorcycle, the acceleration is sluggish and even when cruising the bike does not ride smoothly, jolting slightly forward and back.

Spark plugs – Fouled with carbon deposits. When cleaned, put back in, and the bike started up and warmed up for a minute. I checked again and they are carbon fouled again. Also heavy carbon deposit inside the engine. I’ve bought a new set of spark plugs but I’m not sure if that will solve the problem.

Carburettors – They are very clean when I checked them myself, and cleaned them too, and a mechanic cleaned them only a few hundred miles ago.
The rubber seals connecting to the engine and air box are sealed (so that rules of vacuum leaks).
The floats seem to be set correctly and the jets are clear.

Air box – I took apart and cleaned out, and cleaned the air filters (washed in ethanol, dried, soaked in engine oil, mostly dried). There are 2 holes that have been drilled into the side of the box from the previous owner (maybe he trouble with getting air into the system).

Exhausts – Replaced cracked exhaust (which has holes on the manifold), and other exhaust has pin hole/holes where the pipe meets the muffler.

Engine oil – was black, I have replaced it with the recommended oil.

Fuel – The bike has been sitting in the garage for the last 2 months with a fuel tank so I’m thinking about draining it, replacing the fuel in case deposits have formed that could clog the carbs, and then adding some carb cleaner to the fuel to help keep them clean and free the carbon deposits inside the engine.

IF I’M RUNNING IT RICH THEN WHY DOES THE BIKE NEED CHOKE TO START IN WARM WEATHER? AND IF I’M RUNNING IT LEAN THEN WHY ARE THE SPARK PLUGS AND ENGINE FOULED WITH CARBON DEPOSITS? AND IF IT’S BECAUSE OF WEAK SPARK PLUGS BECAUSE THEY WERE CARBON FOULED, WHY WERE THEY FOULED IN THE FIRST PLACE?

[paddlesat16]

Id wager the carbs have been tampered with, also sounds like the bike has had a hard existence with lack of servicing.

1, I would change the plugs(not keep cleaning)
2, Replace the oil filter cus you changed the oil, and put some more new fresh oil in cus you've just put it through an old filter.
3, check out the carb setting for this bike and set em to factory settings. (I suspect a bodger has been at work here)

Maladjusted carbs give weird symptons
____________________
I once saw a bloke shagging a donkey.... in Saudi arabia. Theory Test Passed 26/10/09 Mod 1 Passed 26/4/10, Mod 2 Passed 7/6/10 Current Bikes Suzuki GSX1400 K5, Aprillia Pegaso 650, Suzuki DR350T.

[G-Sizzle]

I have replaced the spark plugs, and I forgot to mention earlier but I changed the oil filter at the same time I changed the oil and I have checked the factory specs with the jets I have, and they are all the standard. I have set the Pilot screws back to its factory setting number of turnouts (which before the pilot screws was further out, maybe the reason why the engine was running rich, and carbon fouling the engine).

When I put it all back together I will see how it runs, but I read somewhere that carbon fouling (which is all over my engine, exhaust) can build up and effect the valve clearance on my engine, which would explain the poor running conditions of my bike.

I'm going to de-carbonize the engine but I am unsure which way to do it (as I am afraid that if I choose the wrong method, then large carbon deposits can fall loose from the engine wall and then seriously damage the engine interior):

Water vapour - I heard you can spray water directly into the air intake when the engine is running, and it cleans all the carbon out.

Manual - opening up the engine and scraping it all off (with a soft metal so as not to damage the engine interior).

'Italian tune up' - Ride at high speed for a long duration so that the engine gets hot enough to burn all the carbon straight out. (I am also going to but some fuel system and carb cleaner product similar to seafoam in, which I think would help)

[nowhere.elysium]

Whereabouts are you? I'm sure one of us will happily help you out with it.

If you're in or around London, I'm free at the weekends and on Mondays.
____________________
'10 SV650SF, '83 GS650GT (it lives!), Questionable DIY dash project, 3D Printer project, Lasercutter project

[G-Sizzle]

Thank you for the offer, but I would rather do it all myself.

[temeluchus]

Carbs HORRIBLY out of balance?
____________________
Some shite cruiser. Now with guns and FREEDOM!

[sickpup]

It is running both rich and lean and you aren't helping it.

The airbox has been drilled because the previous owner thought it would give him more power. Unfortunately all it did was screw up the carburation so he then richened the mixture in an attempt to compensate possibly also drilling the slides as well.

Cure is...

Gaffer tape over the holes in the airbox, return carbs to standard settings, run bike on a gas analyser to set the pilot screws, ride the bike instead of letting it idle on choke.

[G-Sizzle]

Thanks, I will do that, but I want to de-carbonize the engine really before I tune the carbs so it doesn't effect the tuning. How do I do that safely?

Also, the slides have not been tampered with, and I've only ridden the bike with the drill holes duct taped up, so that doesn't really explain why it would be running lean in the first place.

[sickpup]

[nightshaddow]

[G-Sizzle]

Ok, so I have taken the bike out and noticed it was backfiring through the carbs so I adjusted the pilot fuel/air mix screws another half a turn out and the backfiring has gone away (I assume I as running the bike to lean). I've checked the plugs and they no longer have carbon fouling any more.

with and without the duct tape on the airbox, seemed to make little difference.

I also found that the vacuum inlet nipples on my two carbs, and only one was connected to the petcock (mine is vacuum assisted) so I have connected the other as well (with some more vacuum hosing and a T junction) and that with the pilot screw turn outs I did, the bike has completely stopped backfiring and the plugs are not fouling any more.

With the Carb cleaner I have in the fuel tank I think that now my fuel/air mix is correct, the engine will eventually de carbonize itself.

However there are still some problems that are present.

Even though I have charged the battery up (because it went flat over a couple of months in the garage) the electric start still clicks as if the battery has no charge. I think the battery is quite old, and defunct from losing efficiency from being drained, so I have ordered a new one and will see if it improves things.

And also the bike is still taking a long time to warm up, and very importantly, the bike seems to have no power. (I know it has 45,000 miles on it, but it revs at 4000 rpm in 5th gear just to do 50 miles per hour. I saw the same w650 model on the motorway cruising comfortably at 85-90 miles per hour with a passenger on as well).

I think now, it is the electrics that is defunct and with a poor battery maybe the sparks aren't as good as they should be and thus making combustion in the engine less effective and therefore making my bike less powerful overall.

Let me know what you think, thanks.

[G-Sizzle]

I just spoke to a friend that has had motorcycles for years and he said it could be low compression in the engine and that the poor overall power and hard starting could be a result of that.

[stinkwheel]

Bunging stuff on the inlet manifold doesn't garauntee it's sealed.

Get it idling and spray some EZ start over them. If the revs increase, you have a leak.

I'd also be carefully inspecting the carb diaphragms.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[G-Sizzle]

1. Checked again, and no vacuum leaks from carb boots, manifolds, vacuum inlet nipples, hoses, cylinder head, gasket or exhaust manifold.

2. When I had adjusted my Pilot screw and the fuel/air mixture leaner, my spark plugs stopped carbon fouling BUT the engine was backfiring through the carbs.

When I made the mixture slightly richer (1/4 turn on pilot screw) the backfiring stopped but the plugs are fouling again.

3. Did a valve clearance check and exhaust valves are 0.1mm out (not by much).

4. examined engine and lots of what I think is carbon fouling, but have nothing to compare against.

[G-Sizzle]

1. air filters (cleaned)

2. engine exhaust port

3. exhaust, engine end

4. air suction valve on engine (for clean air system that was never installed (only for California models) but shows carbon build up on inside engine)

5. exhaust, tail end

1. https://picasaweb.google.com/lh/photo/mweQxZuHt4JrK1YtaLaZwNMTjNZETYmyPJy0liipFm0?feat=directlink

2. https://picasaweb.google.com/lh/photo/M2L9il0xy_MQ4xHjYD0yg9MTjNZETYmyPJy0liipFm0?feat=directlink

https://picasaweb.google.com/lh/photo/zUcH0tMKSHVV5zsYemaWD9MTjNZETYmyPJy0liipFm0?feat=directlink

3. https://picasaweb.google.com/lh/photo/FCED4HzYVy37kPu6nXaGKNMTjNZETYmyPJy0liipFm0?feat=directlink

https://picasaweb.google.com/lh/photo/E_Pd6qU2lDmhTYZhil7_ldMTjNZETYmyPJy0liipFm0?feat=directlink

4. https://picasaweb.google.com/lh/photo/ceYmtFNVOKmHeMtWDcLv6tMTjNZETYmyPJy0liipFm0?feat=directlink

https://picasaweb.google.com/lh/photo/3M1zHXSBjU_pcmZMzoBQvtMTjNZETYmyPJy0liipFm0?feat=directlink

5. https://picasaweb.google.com/lh/photo/c-HpBSOc_hWpG_UOXaSN3dMTjNZETYmyPJy0liipFm0?feat=directlink[/img]