1975 340 Sno Twister FA Bogging

TallmanTwister · Post by **TallmanTwister** » Wed Jan 24, 2007 12:22 am

The machine idles rough and bogs when you attempt to give it any throttle. Adjusting the air screw and idle does little to nothing. The Plugs are black(only a small area on the side electrode) and wet. Oil spitting out by the stingers. New throttle cable, filters, fuel lines and vacuum line. Carbs cleaned and removed at present to clean again. Air screw is 1 1/2 turns out. I checked the compression some time ago and if memory serves me, it was above 120. Belt is off. Needle(6DH3) is in the 2nd slot from the top. Main 159 Q-O. Pilot 735. The seven is blocked(like a house number). Thoughts?

440 MERC T T · Post by **440 MERC T T** » Fri Jan 26, 2007 10:52 pm

I'm not sure S/T spec's but I'm guessing it should idle around 3000 rpm, to low idle will make it rich. Jeff

TallmanTwister · Post by **TallmanTwister** » Tue Jan 30, 2007 10:49 am

Jeff. It was idling at ~2800. Now I can't get it over ~1000-1500 and it backfires the odd time.

440 MERC T T · Post by **440 MERC T T** » Tue Jan 30, 2007 8:36 pm

I'm definately not an expert on this subject (or anything really) but try switching the wires that go to the coils. If that makes no differance switch them back and check all wires coming out of engine to cdi. You might have a wonky trigger. JM

TallmanTwister · Post by **TallmanTwister** » Fri Feb 02, 2007 11:58 am

I'll give it a try. Thanks.

SHewelt · Post by **SHewelt** » Tue Feb 13, 2007 11:51 pm

Sounds like the hi-speed winding is bad. Blue wire to engine crankcase (ground) should be 75-ohms...remove the CDI & measure into the engine using 200-ohm scale on ohm-meter. Should be within about 5 ohms.

TallmanTwister · Post by **TallmanTwister** » Thu Feb 15, 2007 8:42 pm

Scott, I found a hole in the carb boots when I was attempting to put the carbs back on from their second cleaning. I?m currently ordering replacements from Jim C at ORPS, which I see your CDI?s are available from him. Good to know and a great guy to deal with. Thanks for the information and I?ll check the CDI in the near future. I don?t have an ohm-scale or meter so I?ll have to borrow one. I?ll let you know what happens.