250 Txt Pro Starting

[jse]

I'm using 80:1 synthetic.

Plug does look oily though - more than I would expect.

Started today after about 6 or 7 kicks, choke on but throttle open!

I may take the carb apart again even though it looks clean.

Steve

Steve,

Check the "starter jet" in the carb, which is on the brass tower with the o-ring. Some Pros came with a #60 (.6mm, a little lean for the starting circuit) and I've drilled mine out to approximately a #80 by using a .031" drill which has helped my engine usually start 2nd kick in any weather (I also have an 02' 280 Pro). The reason you normally don't want to open the throttle when using the "choke" is that the starter circuit is a seperate venturi, using the starter jet, and if the slide is up, air will not be drawn into the starter venturi and extra fuel will not pass through the starter jet.

Be aware that you have a magnesium engine and sidecover so you want to use only distilled water (as you should with any alloy engine). Some riders use straight anti-freeze with good results.

With the newer CDI systems, as opposed to say, the early MotoPlat, I've found they are more prone to just shut down, ie work well or not at all, when trouble occurs rather than deteriorate in performance (provided that the malfunction is internal and not grounding, frayed wires etc).

You also might want to check your reeds (from what you describe, they have 6 years of hard use) and re-seal the manifold and reedblock in the process.

Jon

Edited July 6, 2008 by JSE

[peterb]

Hi Steve,

You have certainly got a difficult one to solve.

You mentioned a few times that there seems to be a lot of oil in the top end. When the bike is going, does it smoke a lot? If this is the case and it is blue smoke, smelling not like 2T oil then either one or both of the crank seals may be passing. If so, the older PRO had separate seals but you can install the newer main bearings fitted to later PRO's that have integral seals. Also, there are O ring seals under a bush on either end of the crank that may have been nicked when fitted, have a look at a parts manual.

Bye, PeterB.

[steveenduro]

Jon - I made a note of the jet sizes when I stripped the carb down and can't find it! I'll open it up again, and check the reeds as I doubt whether they have been touched since new if the rest of the bike is anything to go by.

Peter - The crank seals do worry me, but the bike runs clean and maintains gearbox oil, so I'm hoping it's not. My KTM motor is in bits now, and has noticeable play on the crank at the clutch side - so it's a case split job. So I'll stick with the small jobs for the time being on the txt and see if they resolve the problem. I will at some stage have to tear the bike down as the "growl" on shut-off when in gear needs to be addressed.

Cheers

Steve