I recently purchased a 2006 Sherco 2.9 a few days ago. The previous owner kept it in his heated basement and apparently had no issues with it starting, he said it almost always started the first kick. I am located in Western Massachusetts and the weather has been somewhere between 15 F and 40 F the last few days. The bike is kept in my garage that usually stays just above freezing. Everything on the bike appears stock. Still has the original tires and I doubt it has much over 30 hours based on the condition.


The day I brought the bike home I could not get it started (15 F outside), I pulled the plug and it was wet, I'd assume fouled. Didn't have much time to fool with it so just left it with the plug out. The next night I put the plug back in, garage was in the mid 40's and the bike fired right up on the first kick. 


Bike sits for a few days, it gets cold again and does not want to start. I check for spark, spark is good, I try swapping plugs, no luck. Plugs are dry when I pull them. I layed the bike on its side and drained some gas out of the bowl try kicking a few times, no luck. Pull plug, still dry. I try it again with the gas off and it fires the 10th kick and stalls, a few more kicks and it starts and runs excellent for my hour ride. The air temp was around 35F. 


The next day, today, I go to start the bike and it doesn't start (upper 30's). Check spark, good. Bike has a ton of compression. Plug is still dry each time I pull it. I decided the pull the carb off and clean it, everything looked ok but I pulled it completely apart and cleaned everything. Tried tipping it over and pouring some gas out of the bowl, etc, still does not want to start. Plug is bone dry.


I checked the stuff I read in similar threads, plugs are gapped right (BP5ES at .020-.023 gap, BPR5EIX at .023-.025), pilot jet was a 33, I forgot to right down the other jets. It appears to me to be a carb issue. Are there any other tricks I should be trying or looking at? This is my first trials bike (first sherco as well) but I came from the enduro and motocross world so am a bit puzzled by this, hoping you experts here can help! Thanks in advance!

 

 

 

 Plug should not be bone dry after laying it on it`s side letting fuel into the cylinder. It should prime it to start right up. You do understand the choke should be straight up.

Edited March 7, 201610 yr by lineaway

Turn bars to the right so bike lays fully over on its left side for 5-6 seconds.

There is a mod to drill out the choke jet to enlarge it. I cannot recall the drill to use right now, but if I lived up there I would do it!

We could find out.

Hi. Have you checked if the float is sticking? Tap the float bowl hard with a screw driver handle to release it and let fuel in. Worth a try?

So I know this probably isn't what you want to hear but....

 

I live in MA too. And aside from the last few days, it's been typical New England cold around here. Those days we had that were into single digits, my truck didn't want to start, let alone my trials bike (which is presently non-existent, but you get the idea).

 

I really wouldn't worry about it too much. I had a new KTM EXC-F a few years ago that wouldn't start when it was under 50F, let alone now. Wait till it warms up a bit and I suspect you'll (a) have no problems starting it and b. won't lose any fingers riding it.

Edited March 7, 201610 yr by heffergm

I'm in northern Scotland and it's -4c tonight (28f ?) and I also have a newish to me 06' 290 which I keep in a draughty wooden shed, just tried and it started 2nd kick a few minutes ago, the bike has also been well used but hopefully not too abused so your low mileage/hour bike should fire up quite quickly?

The only other thing I do is to put it into 5th gear then rock it back & fore until the clutch clears, this also seems to help prime the fuel system.

If you are kicking the bike up to around 10 times then the plug shouldn't be dry...are there any inline fuel filters on a Sherco?

What grade of fuel are you using as a matter of interest?

 

So I came home (its in the lower 40's outside) and tried kicking the bike, no dice. Next I tried laying the bike on it's left side for 5-6 seconds as suggested, gas pours out the overflow so I know the inline filter is not plugged as well as the filter on the side of the carb (which I inspected and was also clear when I cleaned it.) I think this should also indicate the float isn't sticking? Kicked it a few times and the plug was dry. I tried laying on its side a few more times and plug dry both times when I pulled it. I also tried tapping on the bowl. The gas came with the bike and smells fresh, it is 91 octane (non-ethanol) mixed 80:1 with Maxima K2. I may trying pickup up some AV gas tomorrow to see if maybe it will atomize better but this still points back to some kind of carb issue to me (or user error?) Still has good spark and compression.

 

As I mentioned it has started on the first kick for me after sitting a night in similar weather. Saturday it started after a about 40 kicks, stalled when I realized I had turned the gas off when I was messing around then started again after about 30 kicks. Then ran perfect for the hour of riding and started hot fine. 

 

What could I be overlooking in the carb? Gas should have a straight shot into the intake and crankcase with it layed over, if gas is pouring out of the overflow, right? The choke does not click on, right (like a keihin on a mx or enduro two stroke) you just adjust it to the up position and there is no positive "click" type engagement? I didn't want to break it putting to much force on it. 

 

Thanks again for the responses, your support is much appreciated as I'm very puzzled. 

 

 

 

 

 

Edited March 7, 201610 yr by rmz290

Reading your description of using the choke is a little confusing, is the lever vertical when you're using it?

On dellorto carbs they act on a overcam principle where the lever has a shape that holds it in the correct position when up, I don't think it's really possible to overdo it as you run out of room pretty quickly

I can probably take a couple of photos of a carb off the bike to show you as I have a Oko flatslide on mine

Below are two pics of the carb just to give you an idea what is on it. Choke is oriented in what I understand on the on position (up). 

Choke is not enguaged fully at that point. Lever needs to stick straight up!

Choke is not enguaged fully at that point. Lever needs to stick straight up!

 

 

Just tried it, fired right up second kick. I guess I should have realized it traveled that far when I took the carb apart, I kept think I was going to snap the level pulling it up much beyond where I felt resistance. Thanks for all the help guys even if it was my own fault to begin with. If anyone is ever in Southwick, Mass for the mx national I'll buy you a beer! 

Edited March 8, 201610 yr by rmz290

Just another tip, you can drill a small hole in the plastic tab to insert a very small wire tie. Makes it mush easier to pull choke off!

That's a mint looking 06' 290 there...great find 

That's a mint looking 06' 290 there...great find 

 

Thanks! It took me 7 months to find a bike, slim pickings up here for anything not beat. Paid a bit more than I wanted ($2900) but the bike looks like it just rolled off the showroom floor.

 

Got some riding in this yesterday, still running great and had a blast. I thought I had ok bike control from racing motocross and riding enduro but it turns out not so much (haha.) 

That's a mint looking 06' 290 there...great find 

 

Looks very clean...nice