Learning about two strokes

[Oscar]

Well, some success over the weekend. I finished assembling the bike on Friday, and on Saturday I got a mate to give me a hand and with a bit of persuasion the snapped off bolt came out. After a bit of testing up and down the driveway, all appeared to be alright.

On Sunday I went up to the WMCC Riverhead trail ride, and met up with Cheese up there (good to finally meet you mate). The bike made it through the day without leaving me stranded anywhere, seemed to be starting fine and was for the most part running really well.

The only thing is, every now and again, it was like the bike didnt want to run up into powerband. The midrange would still pull well, but at the point where the powerband normally kicks in, it was like the bike just ran out of revs. Kick it up a gear, and it would surge forward again, but felt like it was running up against a wall just as where it would normally come on song.

But this wasnt all the time. Sometimes, it would run fine, I had some faster runs on some of the straights where it was going beautifully, but then other times it would stop revving just short of powerband.

So tonight I'm going to look at the powervalve, I gave it a good clean while the engine was stripped down (it was covered in gunk) so I'm going to make sure its not sticking or something.

Its been a fair old mission, but god it was good to get out for a ride yesterday . . .

I had a YZ that did that - it was a powervalve problem (it was a mechanical one and a pin had sheared).

Also check your carby float, it may either be sticking or (and this happen to me once) have a hole in it...

[WRT]

Thanks k14 and Oscar, actually I didnt clean the carb while it was out, if it aint broke and all that. Might look into it though, will check to see if the float is sticking.

Am tending towards the powervalve theory at this stage, but didnt get chance to look at it last night as I got called back into work.

[Brian d marge]

Thanks k14 and Oscar, actually I didnt clean the carb while it was out, if it aint broke and all that. Might look into it though, will check to see if the float is sticking.

Am tending towards the powervalve theory at this stage, but didnt get chance to look at it last night as I got called back into work.

I have no experience of stuffing up the later engines such as yours BUT I HAVE stuffed up mine a few times, My one has the gilllotine type power valves and they can be a pain to put back together, They will LOOK like they are working but actually that is the gas pressure opening and closing them ( If I remember it also ran flat like yours ,,but that was a long time ago and my memory plays tricks )

Stephen