[(F5)]

Ok so I've had this problem appear 2 rides ago, I'm forming a theory but won't get to check it for a while. On that ride I was putting the bike under load going up a hill, but certainly had done bigger hills that this, not intense, in fact earlier I had done a long steep uphill with no drama.

Anyways the bike starts making a rattle & loosing power to the point I decide to stop & restart. I nurse the bike back to the pits & decide what to do. But it is now running fine. I start off for another loop & thrash it just in case if shows an error I can shortcut out of the loop. Runs fantastic, pulls good wheelies. Then stutters coming out of a shallow river crossing.

So back home pull it down & PV is smoothly turning, piston is peachy but very worn, figured that anyway, but no pick ups, no deto marks. Crank seems fine with no movement I can detect wobbling the crank ends or the rod, no discolouring. As you?d expect an 07 to be really.

New piston, fire it back together, adjust the PV so there is no slop (not really much before) in the governor arm.

Next ride yesterday.
All went well, less rattle, ran it in, all good, bike peters out on a hill again with accompanying rattle. No power almost to a stop. Give it a few seconds still running & it comes right & returns to full power. Do rest of 25k loop with no problem.

By now I'm thinking carb float sticking. But makes a rattle that doesn't make me think its running out of gas, but maybe that is deto from lean mixture on a big cylinder under load.

Don't fancy taking carb apart in a field so do a loop on the Trials bike I brought along (its ok it's a GG). Go out & do another loop on the EC300. Up a hill & it looses power again & actually stop, then blipping it trying to keep it running & it stops. Then 10 sec restart it & it clears out & runs fine. Although a few times under load I notice a tendency to seem like it is teetering on the edge. I also notice a few knocks like deto.

So clearly I will pull the carb & check the float valve & check float height. But seems queer as the carb hasn't been apart for several rides. No mechanical issues I can see, even the reeds looked nice from the crank case (top end removed) with a torch.

Water would stop it & make it backfire I would have thought.

Any other ideas?


OK further thoughts. The pipe is a euro road catalytic pipe that was cut open & the cat removed. For some strange reason it rattles more than the other pipe (which is a bit squished). Small poss that something is dislodged & blocking the pipe somewhere. Had this pipe on for about 3-4 rides before seeing an issue.

Can't see the ign going into some queer mode, but possible I guess (happens on rain & full power mode).

So open to the panel: