20 replies to this topic

[Sam]

No spark?

I just replaced the rings in my 2007 290 Sherco. No problem, everything went back together just fine, but I have no spark. I have gone thru wiring looking for shorts, no luck! I have disconnected the competition style kill switch even, maybe a short, still no spark.
Prior to repair it ran good, other than needing a fresh set of rings, I simply washed the bike as usual parked in my basement then 4 weeks later replaced rings.
Anybody have any trouble shooting suggestions, stator and coil I guess would be the next thing to look at?

sam

Edited by Sam, 20 February 2009 - 06:13 PM.

[ZIPPY]

Hey Sam,

Not sure if this is gonna help,

My bike ran excellent last I had it out.
3 weeks or so later I took it to the barn and would not start.
Turns out I sheared the flywheel key.

Cheapest I found if no can get locally
http://www.mcmaster....8490a160/=oqlaz

Didja check where the Spark plug boot connects to the spark plug wire?
Justa thought.

Edited by ZIPPY, 20 February 2009 - 06:37 PM.

[copemech]

What about the spark plug cap? May have been disturbed in the process of doing the rings?

[Sam]

Zippy/Copemech,

Spark cap looks to be fine, Flywheel key I'm not sure about. Do I need a Sherco specific flywheel puller? Do pullers from any other brands work?

Edited by Sam, 20 February 2009 - 07:16 PM.

[rcgods]

A flywheel puller with a thread diameter of 30mm and a thread pitch of 1.5mm. This will fit all Sherco two stroke trials models, many older Montesa Cota, and some Beta models.

[ZIPPY]

When my key sheared the flywheel loosened itself up so much I could just pull it off with my hands.

[Sam]

Zippy,

Fly wheel looks solid, that fly wheel nut loosens left?

ARRRG! I was going to ride this weekend.

[rcgods]

Does undo to the left yes. If you've not got an Impact air gun you may will need to hold the flywheel somehow. I've got a flywheel holder but before I have had to put the bike in gear, hold the back brake on and then loosen the flywheel nut. Sometimes this has to be done by giving the ratchet handle a belt with a hammer. There are other ways to "lock-up" the engine such as feeding a length of rope into the cylinder via the spark plug hole when the piston is on its upstroke.

[ZIPPY]

Quote

Sam Posted Today, 03:43 PM
Zippy,

Fly wheel looks solid, that fly wheel nut loosens left?

ARRRG! I was going to ride this weekend.

Yep itsa lefty loosey.


All I got left as suggestions are:

1. Check ground.

2. The "magic box" that send electricity to plug.

3. Pull Flywheel check key (unlikely), check stator. (That's the thingy behind the flywheel that sends electricity, right?)

4. BFH and apply sharp rapid blows to any part of bike you like. Won't help at all but you will feel better.

[Sam]

4. BFH and apply sharp rapid blows to any part of bike you like. Won't help at all but you will feel better.

Thats the stage I'm at!

I have impact wrench, will remove fly wheel soon as I find a puller or order one Monday.

I have a gut feeling its a disturbed wire, I keep checking them, ground looks good!

[copemech]

Sam, on Feb 21 2009, 11:02 AM, said:

4. BFH and apply sharp rapid blows to any part of bike you like. Won't help at all but you will feel better.

Thats the stage I'm at!

I have impact wrench, will remove fly wheel soon as I find a puller or order one Monday.

I have a gut feeling its a disturbed wire, I keep checking them, ground looks good!

Unfortunatly, that is the way these things go. Next thing is to call buddy with a bike like yours to swap parts. This is where the beer tab starts adding up!

[kjax]

Hi Sam,
My 2004 did similar weird spark things for most of the 2006 season. I found the problem to be in the consitent grounding (or lack of it) of the electrics under the tank. I completly removed every part and connection, brightend them and coated each with di-electric lube when reinstalling. The problem has since gone away. When I simply removed, cleaned re-assembled the fix would not stay put. The di-electric lube seemed to be the trick. Good luck ...

[firstgear]

Sam
For What its worth Beta and Sherco use the same flywheel puller. I could send you one but I doubt that is it.

Take the kill switch right off and try for spark. Also try a couple new plugs. Last year I messed with my bike for well over an hour due to no spark.
I added a new plug and nothing still so I messed with other stuff. Some reason I pulled the plug and tried another and it fired right up.
I don't trust new plugs now and always have several.

1. Remove Kill Switch and check spark.
2. Check ground to coil.
3. plug boot

It really should be one of those if it was running fine before tear down.

[Sam]

How do you tighten the fly wheel? I took it off with the impact wrench, do you give it a light zap with the impact to tighten or do you use specific torque (lbs.) settings.

Hurray, I have spark!

Thank You everyone for your suggestions, tomorrow I will tell the whole story.

[ZIPPY]

From one of the "Wayne's Guides"
"The factory torque is 73.2 ft lbs"

This last time I used my torque wrench set at 73 ft/lbs and one of those rubber strap wrenches wrapped around the fly wheel to hold it in place. Bike was in neutral.

HOORAY HE HAS SPARK!!!