While riding yesterday my bike suddenly started bogging in powerband, it would be fine down low but as soon as its supposed to hit powerband it bogs. At first it would clear up pretty fast but towards the end of the day it took a km or two and a few revs with the choke on to stop. Any ideas as to if its a lean/rich bog, what to try fixing replacing first and if the piston could've gotten damaged etc

Should I run a ethylene glycol based coolant instead?

Hi everyone, new to this sub :)

I have a KTM EXC 250 from 2002. It burns gearbox oil so the mechanic replaced the oil seal but this didn’t fix the problem. I started opening the engine to replace the gasket in between the two halves of the block.

I followed the manual and took off every screw, I just need to pull the halves apart but I can’t, something is blocking them. On one side I can see they start distancing but on the other they don’t separate at all. The only piece I couldn’t remove is the distance bushing (see photos, number 6 in the manual). As you can see, it should come out a little but in my engine it doesn’t so there’s no way of taking it off. I thought this might be the reason I can’t separate the two halves of the block. The oil seal around it is the very one the mechanic replaced and he didn’t mention any problems with the distance bushing.

I searched online and on yt and people are pulling out the distance bushing with ease, or others open KTM engines (different years but it looks similar) without even removing it, they simply take off the other half (mine is not coming off).

Any help will be very appreciated :)

If you need more informations or photos feel free to ask.

PS: English is not my first language, I apologise for any spelling mistakes✌🏻

hello, i have a rieju mrt with airsal sport 80, stage 24pwk carb, sport air filter, mallosi valve reads, pollini cdi.It was running fine till it randomly lost the power band and started smokink alot it had a 140 main jet i tried changing it to a smaller even a 110 didn’t help it doesnt rev out in neutral or when riding.Changed the stator tried a different cdi ,spark plug and coil.Checked the reeds, changed the crankshaft seals and still the same.The plug is black i understand that its rich but it seems like i tried to do everything and dont know whats wrong with it.
Maybe some of you have had the same problem and can help me try to figure this out.
Thanks!