Terrible mid range bog

[Ryderod]

Howdy,
I have very bad mid range bog, and have to crank the revs and blip the clutch to try get rid of it. What is the most common cause here?
The bike I bought, an EC300 does not have the correct silencer, but I have managed to get hold of a 2nd unit which I will fit.
I'm thinking jetting or needle position could be out, or maybe even crank seals, but have been told these Gassers are prone to bogging?
I am at about 1500 meters above sea level..

 

[Boom Boom]

Start with replacing your pilot jet, very easy to plug...does not flush out well and will kill your lower torque if plugged.
As far as Gassers liking to bog...that is just plain crap.
Mine will grunt down low and pull better then any 2-stroke I have owned (other than my trials bikes).
Start simple before trying to complicate things.
Get a decent pipe on that is packed proper to give a little back pressure. This is not your problem but it will help.

 

[motopsycho87]

Almost certainly rich jetting.

 

[nambo-trev]

+1 on rich jetting for sure, if it sounds like burbing and gurgling lean it out.

 

[AZRickD]

On the other hand, if it is no "burbling" and is just down on power, then it is lean in the mid range (and likely somewhat lean on top as well).

Try raising the needle one clip. Is it a tapered needle?

 

[Jakobi]

Could be this, could be that, could be something totally different again.

We can offer suggestions, but you'll need to give more to get more.

What state is the engine in? Hows the ring end gap? How are the reed petals? Has the carb been pulled, cleaned and inspected? If so what model carb is it and what jetting configuration is in there? When you say it bogs, is it breaking up and burbling, or is it gasping, hestitating and trying to stall when you open the throttle? Makes a big difference.

 

[desertgasser300]

Could be this, could be that, could be something totally different again.

We can offer suggestions, but you'll need to give more to get more.

What state is the engine in? Hows the ring end gap? How are the reed petals? Has the carb been pulled, cleaned and inspected? If so what model carb is it and what jetting configuration is in there? When you say it bogs, is it breaking up and burbling, or is it gasping, hestitating and trying to stall when you open the throttle? Makes a big difference.

Were you riding in sand or mud.......J/K

 

[Jakobi]

Were you riding in sand or mud.......J/K

That stuff gets me bogged almost every time! I've tried everything, but a new tyre seems to work best, with a couple less psi

 

[Ryderod]

Could be this, could be that, could be something totally different again.

We can offer suggestions, but you'll need to give more to get more.

What state is the engine in? Hows the ring end gap? How are the reed petals? Has the carb been pulled, cleaned and inspected? If so what model carb is it and what jetting configuration is in there? When you say it bogs, is it breaking up and burbling, or is it gasping, hestitating and trying to stall when you open the throttle? Makes a big difference.

Thanks for the replies, yes I haven't supplied all the correct info as I have recently purchased the bike and am battling with this problem from day one, on any terrain. When she bogs there is no danger of it trying to stall, more like a distinct hesitation, as if the power band does not want to kick in. Tapping off slightly on the throttle helps a lot when this happens.
I was basically putting the question out here to get an idea of a set of things to check. But I have not stripped the carb, so have no idea on jetting, nor needle position.
My first task will be to fit the newly purchased silencer, which was from the Gas Gas dealer in Cape Town and has been repacked, so it will be spot on. Plus I will replace the header O Rings as there is a bit of splooge leaking from there.
I will get to the carb this weekend and get the needle position and type, as well as the jetting, and post the specs here, and check reeds.
Without removing the head to check ring gap, would a compression test help in determining engine wear accurately enough? If so, what compression reading would be acceptable?
I must say, apart from the bogging, I am really enjoying this bike!

 

[Jakobi]

I'd say the piston will be fine. If it starts well compression is likely not an issue. New set of rings every 100hrs isn't a bad thing but they will run on for much longer especially if maintained and not spanked too hard.

The reeds can cause the issues you're describing. Once you find out whats in the carb I'll happily offer up some specs which may work better. If its the stock N1EF needle it'll be 90% of your issues.

 

[KTMAndy]

Just been reading this.

I've been helping a friend who's just bought a 300 gas gas. I had a go on it today.

In 1st and 2nd when warm. It feels like it's still cold. The more you twist the throttle the more it fights you.

As soon as you hit 3rd it's a different bike. Full of power and wants to rip your arms out.

1stly there's bags of compression.

We took the carb off tonight after the ride out. The pilot jet had a split in it... The floats where twisted by about 5 mm difference between the two sides.

The main jet looked older than me. The numbers where un readable. But compared to a 174 it was still a lot wider.

The needle is standard needle but on clip 1.

With it being dark. We haven't had chance to run it up yet.

But I've balanced the floats. Replaced the split idle jet for a std 38 and replaced the main with a 174.

I've left the needle on clip 1. As I didn't want to alter too much in one go.

I'm hoping this will lean it out a little.

If it's not working. I'll try a fatter needle and start on clip 3


I'll let you know!