Sherco 290 2004 Carb Help

[padilant]

Can anyone tell me what the correct needle clip position is for a PHBL 26 all jets are standard 33 pilot and 124 main it's currently set second from bottom any help much appreciated cheers

[dadof2]

Depends on your altitude, oil mix ratio, air temp, air density and humidity. Put it in the middle and give the bike a good run on 3/8 throttle and check the plug colour, should be milk chocolate brown. If it lighter lower the clip, if its darker raise the clip.

[copemech]

Can anyone tell me what the correct needle clip position is for a PHBL 26 all jets are standard 33 pilot and 124 main it's currently set second from bottom any help much appreciated cheers

Second from bottom is fine. If there is not a specific problem here, leave it!

Jets are in general range, yet many run a bit larger pilot, 35-36 range for a bit more pep, and a bit leaner main, 118-120 range, for a better run-up!

[tony27]

Checked to carb I took off mine when I fitted the oko & second groove from the bottom off the 4 is how I ran it, will have to wait until tomorrow if you want to know the rest of the settings as I'm off to work all night shortly

[padilant]

Cheers for the help guys all seems ok with carb spoken to someone at malcom Rathmals today and all is fine with carb but bike still looses power in 3rd going up a hill climb I've checked all the simple stuff first as you would but have just taken the fly wheel off and the timing looks as if its been retarded almost all the way ( can see some marks on the coil plate where the washers have been before ) but these marks seem to advance the timing nearly all the way am I right in thinking that the factory setting would favour a more advanced setting any help on this would be great only had pretty limited experience with timing cheers

[dadof2]

I am not familiar with the exact details of the ignition on a 2004 sherco. Put alignment put marks on your flywheel and case that align when your piston is 2.5mm BTDC (before top dead centre). Run the engine at idle and check the alignment of the marks with a strobe. Rev the bike and see if the timing advances.

your lack of power could be ignition or carb related. If the timing is retarded the engine will get too hot under sustained load and you could even seize or hole the piston.

Some shercos suffered from a lack of fuel flow through the carburettor float needle valve, the cure is to drill it out a fraction. Lack of fuel flow causes the lack of power you describe and can have the same consequences as retarded ignition.

I would speak to MRS again or AG bikes (Reeth) especially to get the exact timing details (2.5 BTDC is an educated guess) Do get the problem sorted or you mike be looking at a £400 bill for piston and barrel replate.

[copemech]

Cheers for the help guys all seems ok with carb spoken to someone at malcom Rathmals today and all is fine with carb but bike still looses power in 3rd going up a hill climb I've checked all the simple stuff first as you would but have just taken the fly wheel off and the timing looks as if its been retarded almost all the way ( can see some marks on the coil plate where the washers have been before ) but these marks seem to advance the timing nearly all the way am I right in thinking that the factory setting would favour a more advanced setting any help on this would be great only had pretty limited experience with timing cheers

So that's the issue. Might ck the number on the float jet housing. If say a 200, you may want to go up to say a 250.

Set the timing back to orig mark on stator and top web casting.