Suzuki AY50 Katana Air Cooled Poor Performance

[Door]

I'm a girl please HELP!!!

Brought one recently, has got a Leovince exhaust. I've fitted new barrel and piston (standard), new reed valve petals and block and a new belt, but the performance is shocking!!!!

Has a top speed of about 20 mph and 10 mph going up hill

Have de-coked the exhaust - should the main jet have been changed to suit the exhaust? If so any advice on what size?

Do you think i should now change the rollers?

[dangerousdave]

There's something very wrong with that.

Are there any oil leaks around the cylinder (possibly loosing compression)

Have you cleaned the carb out (possibly blocked jet/s)

Any holes in the exhaust ?
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Door]

Hi Dangerousdave,

i've checked that no oil leaks i've fitted a new barrel and piston

No i havent cleaned the carb as it is actually running it will start and rev but has no power

No holes in the exhaust either

[dangerousdave]

Might be worth checking the carb then. A blocked main jet could cause the problem you're describing.

Has it been stood up for a while?

When did the problem start happening?
____________________
1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Door]

ok cool thanks for the advice, going to give that a go.

I really dont know how long it has been standing as i only brought it a few weeks ago although it did come with 12 months MOT and tax too

[dangerousdave]

Also, what colour is the spark plug head when you remove it from the cylinder. This will give you an idea of whether the correct mixture is getting into the engine. Black & oily = too rich. White = too lean. Tan/creamy brown = about right.
____________________
1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Nope.]

Right, Basic stuff to check with a two stroke:

1) Is the Airbox/Airfilter connected correctly? Is the filter clean?
2) Change the sparkplug. They're consumable items on 2 strokes.
3) Oil - Make sure its getting to the crank case
4) Petrol - Make sure petrol is getting to the carb
5) Carb - Strip and clean it, use compressed air (In a can if you dont have a compressor) and STP carb cleaner. (Can be had for around £5 a can on ebay)
6) Inlet manifold rubber - If its still not running right, check that the manifold isnt leaking by spraying some wd40 all around it whilst its running and seeing if it revs up.
7) Compression - Break out the compression tester (If you dont have one then get one) and see what the compression is compared to what it should be.

Now, from what you've said id guess that its running lean. If they havent up-jetted when they've fitted the exhaust then it will be running lean. You need to upjet 10-12% over whatever is in there, read the size off the jet and then go online and buy one.


Where abouts are you? Im sure somebody near you can come and help if you want.
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Former: Derbi GP1 50, Sachs XTC 125, Suzuki GSXR 400 GK73A, Kawasaki ZX7R, Suzuki DR250, Yamaha RD350
Current: 2011 Yamaha XT660Z Ténéré, 2003 Yamaha YZR-R1 5PW (In Build), 2009 Kawasaki ZZR1400