1979 KTM 250 hard starting

[GeorgeBressler]

New motor & HPI ign by Gary Ellis. Once it starts it is as good as any dirt bike I ever owned. Idles perfect, starts first kick (AFTER IT'S WARM). PERFECT, MASSIVE HORSEPOWER. Perfect but miserable to start. All jets from Bing agency intl.. What am I doing wrong? I tried tickle til it pukes. Not tickle at all, tickle a little bit, starting usually requires a new plug. Running 40:1 Golden Spectro with 93octane non-ethanol. Thx for any help. About ready to switch to Mikuni. George Bressler

[Daniel P. McEntee]

Have you checked the pipe from end to end for any blockages? It gets over looked all the time because it's easy to miss. Check everything in the spark arrester, silencer and such, and the header can get pretty coked up over time. If it can't exhaust, it can't intake. When it's warm it can get enough through for operation, but when cold things shrink up. Check the choke circuits also if the Bing has one, and if it does, do you use it along with the tickler? What does the plug look like after running a while? Are you gapping them correctly? Make sure the idle jets are clear and passing air when removed from the carb and the passages related to that circuit. This is all the basic stuff, and just one of them will give you problems.
   Type at you later,
    Dan McEntee

[Toolsurfer]

Fuel on, set choke,tickle till gas run out over flow tube, kick, I also run golden in mine also. 74 1/2 250 . Cold 2-3 kick and she's running.

[Carl Hill]

Not familiar with HPI ignition but you may double check the timing to make sure you don't have too much advance. I have 2 250s and both start easy. I don't have choke slides in either one, tickle the carbs till they " puke" like they just ate a large meal or 1/5 of cheap wine. I used to work at a dealership and we would often start big bore Japanese two strokes by leaning them over until they did the same.

[skiracer]

Buy the Mikuni and be done with it.

1976 250 MC5 Original Owner
1976 Penton 175 XC

[KJDonovan]

I'm with Dan - Check the pipe, you would be shocked at how much crud can build up in these.  Pull it off the bike, roast it with an acetylene torch until it is completely burned off.  Just my 2 cents.

Thanks,

Kevin

[JP Morgen]

When you kick it while trying to start, does the engine "spin", or does it barely turn over once? If the later, lower the compression, add flywheel weight, or go back to a Motoplat. A friend brought a 400 to me that was doing exactly that, started first kick with the Motoplat. Just a thought.

[GeorgeBressler]

Thx to all who replied. I do not think the pipe is blocked. I do not have the luxury of a choke lever. Tickle only. Since this post I have been able to get it to puke out one overflow tube only. (Right side sitting on bike).I blasted carb cleaner through both tubes. Talked to Gary Ellis & he doubts the ignition is the problem. As I said, once running, this bike is pure magic. Skiracer, can you suggest where to get a mikuni and any specific model other than 38mm....thx again, George B

[Toolsurfer]

I thought all bings had a choke slide?  am I wrong?

[Daniel P. McEntee]

I have seen a lot of crazy things on old Bing carbs, but despite their short comings I do think that the run the best with them when everything is correct. I have a '77 Hercules GS-250 7-speeder equipped with a Bing with choke and tickler. It was hard to start cold also. I finally noticed that when tickled it would not over flow and it took a lot of kicks to prim the engine with the choke. So I pulled the carb apart and played with the mechanism and found that the plunger for the tickler would not touch the floats! I double checked the carb model and numbers and ordered up new part from Bing International (OUCH!!0 and compared them and saw that t hey were not long enough to reach the float either. I called Bing again and their technician was no help, so I resorted to good old Yankee ingenuity and made an extension that would push the float down. Then, combined with the choke, it would start one or two kicks cold no matter what.
    Some of these old bikes just need a lot of gas when cold. Your bike is like my '75 WR-250 Husky with a Bing and no choke. Old Husky really liked to be drowned in gas to start cold. I think you may not be flooding it enough, or there may be something wrong with the tube in the carb where it over flows too early and you don't get enough gas to go into the engine. Pull the carb down and check into that detail as close as you can. If you can't find anything, the next time you start it cold, pinch off the over flow tube with something for an extra couple of seconds, then try starting it and see what happens. It may be that simple, or that even though you were getting gas to overflow, you may not have been flooding it enough for a cold start.
  And don't guess at the pipe, check it out and be sure. That same old Husky of mine had these symptoms once and the wire mesh spark arrestor was plugged solid. If you have a nice, fresh engine that may over come a plugged up pipe for a while. If you have never cleaned it out and the pipe has a lot of time, I can assure you it WILL have some carbon built up in it in a lot of places. It is a two stroke and it's the nature of the beast. Best to be sure, and if it is clogged up, and you think the bike runs great now, wait until you get the pipe cleaned out and then hold on to your helmet!  Your comment about always having to put in a new plug should be telling you something also. What does the old one usually look like? Black and sooty or biscuit brown? You want to shoot for biscuit brown.
   Keep us posted on progress. I love a good mystery!
   HAPPY INDEPENDENCE DAY!!
  Dan McEntee

[Daniel P. McEntee]

quote:Originally posted by Toolsurfer

I thought all bings had a choke slide?  am I wrong?

    No, there are some that do not have a choke. The Bings on most old Huskies do not, that I have seen. I can't be 100% sure about the bigger bore Pentons.
  Type at you later,
  Dan McEntee

[Timothy Walls]

I remember the old 360 Husky I had to lay it on the left side to start it . I also rember starting it one day and it backfired .Restarted - let the clutch out and it was running backward . The backfire sheared the key on the flywheel and changed the timing . Thoes were the days.

Timothy Walls

[Daniel P. McEntee]

Another starting tip to remember is to try NOT to crack the throttle when starting cold for the first time. Get the engine primed, and maybe make three or four slow kicks through compression with the throttle closed. The slide can act as sort of a choke and crank case vacuum helps pull fuel up into the engine. The tipping over trick helps with getting fuel to flow into the engine. I'm still interested in the plug. What kind is being used, what gap, and how it looks after some running and plug tests.
  Type at you later,
  HAPPY FOURTH OF JULY!
  Dan McEntee