howard wallace

Two or three cylinder base gaskets will also dull it off. Sherco provide several different thicknesses.

Not sure what barrell you have ?. Sherco didn`t make a 100cc. 80cc is 44.5mm bore, 125cc is 56mm, measure what you have before jumpin in.

19 mm with carb at 45 degrees. Hunting at idle will be pilot circuit. screw in pilot screw will richen, use range of 1/2 to 1 1/2 turns out. If outside this range change the jet. ShercoH

Jay, I`m all for what your doing !!!! And sorry for passing any comment.

Hey Zippy, Not sure what type of "Engineers" you`ve dealt with. Here in Australia Mate we engineers turn our "Theory" into "Reality". Here`s one of my goes in 1983 !! http://picasaweb.google.com/Shercoh/Images...583975773909762 And another in 1992 !! http://picasaweb.google.com/Shercoh/MyPict...596615862661922

I`m also interested.

Hey Simmer, I have a heart, that`s why Ive commented!!!!! I`m a Mechanical Engineer, and what I see in your photos is a real worry.Hope you don`t get hurt by it !!!!

Wouldn`t be leapin off too much with that !!!!! Frame needs motor to be a stressed member.

lifting the needle has richened the area above the idle/pilot circuit. What small improvement it makes is due to the extra fuel residually left after opening.You need to adjust the idle circuit as that controlls when the slide is fully closed. Don`t recommend you change ignition from factory specs,while chasing this. Change one thing at a time.

Try lowering the idle. This allows less air into the pilot circuit, if that stops it then the pilot adjustment needs to be richer. Bit of a juggling act between what idle you want, bottom end smoothness and over run pop. Does the motor rattle when you float along at a very slight throttle opening ? Cheers ShercoH

Yes, it will fit and the motor will run fine. You`ll find it a much easier motor to use compared to the 80 that has virtually no flywheel. The correct 125 flywheel is about 10 mm diameter smaller than the 290. Recommend you run heavy to start, and lighten as the boy develops more clutch , throttle,technique.

125cc complete top end fit straight on. Bigger flywheel helps too.

If you must run breather pipes on the Dellorto, join them together with a small pie cut out of the middle. Hang them down near the bash plate and they will suck up water. Learnt the hard way in 99 !!!

Check that the long brass tube that sticks out of carb ,when float bowl is removed is cleared out. That`s the choke circuit, has a small o-ring on the end that gets cut aswell. Chamfer the float bowl where the o-ring fits in. Always left sharp by Mr Dellorto, causes many problems !!!! ShercoH

Sounds like there is an air leak, in the header pipe to barrel copper gasket, or the o-rings in the front of muffler. Need a good air supply to get muffler that hot. Seen it happen on a brand new bike when homologation header was changed, and the competition one was poorly installed. Melted plastic guard first ride. Had nothing to do with oil build up. Cheers, ShercoH

Peter B, 320 weighs 1.5 kg more than the 2T, so the 2t must be a heavy lump to you as well ???. I own both, and the 320 has heaps of power. Far more than anyone but an Expert would know what to do with, and I believe the most power of all the 4t`s. What grade do you ride ????? Hop Blip, Latest 320 has dual map ignition,with the flick of a switch. KeiHin flatslide and a Hot Start circuit which was the biggest problem with the early model

Neo, One problem with the Dellorto, is the O-Ring on the end of the choke tube. Where it engages in the float bowl is usually very sharp, and cuts the O-Ring, causing various low speed mixture problems, Get a twist drill and chamfer the edge of the hole in the float bowl, a tiny bit of rubber grease helps it slide in easier. Replace the O-Ring, then you have a stable base line to start tuning from. But pay close attention to it every time you take the bowl off. KeiHins never have this problem, I know what I`d rather be tuning !!!!!!!!!!! ShercoH

Steve, Could be a crank seal on the clutch side of the crank, will cause lots of smoke with poor bottom end.

Hen, First thing you always try on a two stroke, is a new spark plug. Use an NGK BP5ES. The 5 is the heat range that must be used for this bike. Then adjust the small screw on the left hand side of carb. It should be 3 to 4 turns out. Wind it in and less fuel, out , more fuel. Warm the bike up and try adjusting a 1/4 of a turn at a time till you feel the motor smooth out ,just as you open the throttle you should be able to notice a big change in the way the motor feels. If not the pilot jet could be blocked.

Panel beaters tool called an Easy-Beat, spot welds a washer to centre of ding, and hooks a slide hammer into washer and pulls out dent. Will damage chrome slightly though !!!!!

Check that your fuel tap is ok. Some needed the tube inside shortening, and would only supply enough fuel on reserve.

There is a small o-ring that seals the choke tube into the bottom of the float bowl. Choke tube is the long brass 4mm dia rod and fits into a hole cast into the bowl. The edge of the hole in the bowl needs chamfering as it usually cuts the o-ring, and causes similar problems to that you`ve described. Worth a quick check. ShercoH

Neo, the symptom you describe, sounds lean on the pilot. Air screw should be 1/2 to 1 1/2 turns out. Anything outside this range requires a jet change. But your running a 48, which should be plenty of fuel, so don`t understand ????

Neo, Ran that combination on the 4T. What you have is fine, except for needle clip position ????