03 Sherco 250 + Fast Barsteward Set Up

[flyingpeach]

Could anyone advise me on what setup I should go for on my Sherco 250 please, I'm 14 stone 8lb.

Cheers

[bikespace]

At your weight, bog standard will do, so your weight isn't likely to be the important factor.

What level of rider?

The reason I ask is that novice riders sometimes like to tame them down a bit with things like slow pull throttle, base gasket, fly wheel.

Generally I'd only mess with the throttle first and see how you get on.

[ham2]

My opinion is:-

Novice rider =Slightly retarded (ignition that is).

Clubman rider =Standard at factory mark.

Expert rider =Advanced for extra snappiness !

There's quite a range to be played with just check that the bike doesn't run too hot.

[copemech]

Agree a standard 250 should be fine, use a slow throttle if you are unsure and be sure you have a good working clutch ald lever in proper adjustment, as it is your lifeline to application of power!

[flyingpeach]

Thanks Guys,

Just one more thing, I was told by a mate today that Shercos are said to have a "snappy" throttle which is difficult to control for a beginner like me. Does anyone else agree? If so is there anything I can do about it apart from a slow throttle?

[copemech]

Thanks Guys,

Just one more thing, I was told by a mate today that Shercos are said to have a "snappy" throttle which is difficult to control for a beginner like me. Does anyone else agree? If so is there anything I can do about it apart from a slow throttle?

There are a number of "tweaks" to make them more gentile. The 2.5 is still a high performance bike to begin with and responsive.

Only YOUR riding level will determine the limits. As stated, if you feel it too sensitive on basic things like no clutch figure eights, try the slow throttle for better feel. Cost little.

Slowing the timing by 5-6mm on the backing plate will soften the power. Cost nothing if you have the tools.

The Boyesen reeds will Smooth the power off the bottom. Only a few quid plus some work.

And lastly, a 44T rear gear of a 1.25 will slow how far yoou are propelled by the bike in a given gear. A 9T on the front will give double the effect and before long you are revving like a 125 and going nowhere!

You can really turn that bike into a tractoring pig if it suits you.

Learning proper throttle and clutch control, priceless! Try using second gear in slippery stuff and cambers, forces you to use the clutch for control and feel, just set the throttle?

[ham2]

Thanks Guys,

Just one more thing, I was told by a mate today that Shercos are said to have a "snappy" throttle which is difficult to control for a beginner like me. Does anyone else agree? If so is there anything I can do about it apart from a slow throttle?

I refer the right honourable gentleman to my previous answer...retard the timing,it's much less snappy and less likely to stall.

[copemech]

I refer the right honourable gentleman to my previous answer...retard the timing,it's much less snappy and less likely to stall.

True, and reduces kickback when starting!

[flyingpeach]

Ok I've got the 44 and 9 sprocket, any advice before I go head first and change it? Actually can someone tell me how to do it before I go and put the heating on the garage?

[bikespace]

Jesus - the 9 and the 44 at the same time will give you the equvalent of about 10 and a 48.

I suppose the fronts only cheap so you could always go back to a 10 for a few quid. Make sure you don't cut your chain too short to do that though until you're happy.

I'm just concerned you may be making your 1st gear unusable?

Bigger snailcams may hep you with chain length - trialcast do some decent ones that allow you to take a full link out on the Sherco between full adjustment and no adjustment.

If you're asking how to change the sprockets, the rear is just 6 allen bolts (with nuts I believe rather than captive screws), so you can get some weight on with the spanner without rounding the hex keys. The front is a circlip you need to remove, then just pulls off. Measure the chain to size then cut to the length you need, or grind the link with an angle grinder if you don't have a chain cutter. The purists will cringe at the angle grinder, but does he same job if done carefuly. I've never bought a chain cutter

Just don't cut too much off :-) Easy to cut again, very messy to add links back in ;-)

[copemech]

Remind you that the timing change and slow throttle are first, did you do any of that?

[flyingpeach]

OK, I've done the slow throttle, I'll do the rear sprocket (what do you think) and how do I adjust the timing copemech? Thanks for the input by the way.

[flyingpeach]

My opinion is:-

Novice rider =Slightly retarded (ignition that is).

Clubman rider =Standard at factory mark.

Expert rider =Advanced for extra snappiness !

There's quite a range to be played with just check that the bike doesn't run too hot.

I'm a retarded novice

[copemech]

OK, I've done the slow throttle, I'll do the rear sprocket (what do you think) and how do I adjust the timing copemech? Thanks for the input by the way.

You would need the flywheel puller tool, not costly. More later!Timing setup

A good 3/8 drive rattle gun is preferred, as a large 1/2 drive is a bit much unless extreme care is taken.

Link to old thread pic from '07. Pic illustrates the backing plate rotated counter clockwise approx 4mm from the satandard factory setting where the "tic" mark aligns with the right edge of the casting webb.

I normally use the "cheat" method for flywheel removal and installation.

Using a dremel tool, scribe an alignment mark on the crankshaft end and the flywheel retaining nut to be used as a torque reference upon reassembly. You know they are right from the factory as the Spanyards always build good things!

Remove the nut with a rattlegun and set aside. Using a felt tip marker, make a short line along the outer radius of the flywheel where it aligns with the case. This may be used later to establish that the flywheel has been fully seated into position upon reinstallation.

Fully engage outer(fine)threads of puller into flywheel, then seat center screw against crankshaft. Using rattlegun in forward

(right)direction against center screw, flywheel should pop loose from tapered shaft fairly easily. If not, a fair blow on the head of the forcing screw should break loose the taper holding the flywheel. Note that both the plastic cover and the flywheel may almost always be removed with a bit of manipulation of the gear lever. May require placing bike into neutral, then fully depressing lever down into first gear and holding fully down while flexing lever outward just a bit.

Set aside flywheel and inspect for proper position of alignment keyway in crankchaft. It should stay put normally. You may use the kick lever to rotate to "up" position. This may help later when reinstalling flywheel. The keyway IS you locating device.

If your cover has been leaking mud, dirt and water, you may find things rather nasty in there. Might be a good time to clean things up well and and apply some protectant such as WD40 or Tri-flow, LPS #2 works well.

Avoid brake cleaner in this area as it will take the paint finish off the motor case.

After finding the "tic" mark, loosten the three backing plate screws and make your adjustment. Re torque screws just hand tight as you do not want to strip them.

Insure tapers on crank and flywheel are clean and dry.

With flywheel oriented with keyway slot "up" in one hand and the dreaded shift lever in the other, you must now manipulate the flywheel back into position. Once past the lever, you will likely need to rotate the flywheel back and fourth a bit untill you feel the key align and the flywheel seat fully on the tapered shaft. Do not force things as you could dislodge the keyway. Once seated properly, your outer reference mark should line up properly and the flywheel should rotate with no wobble turning by hand you will feel it working against the engine compression as things are now rotating again as one. Reinstall large nut and snug by hand to hold things secure. You can then use the kicker to rotate the motor to once again insure that everything is rotating straight and freely prior to re torqing the nut. I would estimate it would be about 1/2 to 1 turn shy of your original scribed alignment marks at this point.

Then using rattle gun and socket, carefully tighten the nut to its original position or just ever so slightly beyond. Stop and check a couple of times along the way to be sure you do not over do it. The last thing you want is to strip something now!

If there was evidence that your plastic cover was holding water and dirt causing corrosion, now would be a good time to drill a 2mm hole in the center bottom of it. This allows anything that might get in, to get out, including moisture to vent. Having owned a few, none were ever watertight untill my current '07. The rest were far better off with the vent hole. Grab your lever again and reinstall cover. Always lube your screws with a bit of grease or anti-sieze on the threads!(as well as the rest of the bike)

Fact is, I have tried to give great detail and precaution here for those who might be a bit mechanically challenged or inexperienced. It would probably take me longer to read this than to actually perform the act. The entire thing can be done in just a few minutes, barring the cleaning that may be neccessary. There is enough detail that you could print this off and hand it to your local plumber to do if you are unsure or ill equipped. Find an experienced buddy!

If you do this by hand method, you will need to make some type of flywheel holder to hold things while you pull torque on the big nut, which is around 60-72 ft/lb.

I have done a fair amount of experimentation with the timing settings on both 2.5 and 2.9 bikes and the results are basically the same for both. If you only move the plate say 2mm toward the retard you will likely tell no difference, going back 6mm seems to be the maximum that the bike still runs correctly, and a minus 3-4 mm range would be your tradeoff. I think my current 2.9 is at a -5mm right now. Quite smooth when combined with the Boyesen reeds and proper jetting using stock gearing. Mind youI am lightweight at about 175lbs, and the 2.9 has no problem. Not sure just how many stone that is?

Edited November 28, 2008 by copemech

[flyingpeach]

Thanks for that copemech, I'll give it a whirl and let you know how I get on. I'm using the bike at the weekend so I'll start Monday.