just wondering if anyone can shed any light on my issue. I've just bought this bike as a project i has a flat spot at about 1500 to about 2000rpm. i believe its been bored out to 810cc has a lazer can and K@N filter. i know for a fact that this bike has been dynojet at some point by the previous owner. From reading the printout i have. The 1st run there was hickup in the power curve up to 4000rpm for the 2nd run :- 120 mains, needle grv 4(no Spacer) idle 3.5 turns out. this had seem to fixed the power delivery to 400rpm. but its still ropey to 2000rpm

Don't know about the yam but i had a full stage 3 tune on a suzuki 600.

Cams, vernier gears, filter with a full 4 to 2 to 1 race pipe (not a 4 into1 thats nasty) with the limiter lifred and a full dynojet kit.

The dynojet had different jets for the carbs depending on it being an inner or outer cyl.

That had 32 dyno runs all told to get right all done by TTS.(SUPERB PEOPLE)

Below 5 was a waste of time from 5 it was smooth as glass and from 8 it fked off like it was shot from a cannon.

I would stay over 2k rpm. Why are you riding it that low anyway? Its doing the bike no good at all.

It's only problem when filtering in slow traffic and slow pull offs. The rest of time the bike flys

It's only problem when filtering in slow traffic and slow pull offs. The rest of time the bike flys

Price you pay for the big bore. Just keep the revs higher. I'm surprised you can ride at that rpm.

Even my dt175 gets the arse at 1500rpm its barely over idle. The TDR would sooner foul plugs than run under3.

If its something you really must fix a good carb balance should fix it. By that i mean done really accurately as at that rpm the carbs are barely open. That is the most likely cause of the flat spot.

Cheers I'll give that a go