I feel a bit seasick after watching that
Just been reading through the Yamaha Bulletin again, I wonder if the 2 hours to mod the piston under warranty is still available
That surging is a real pain in the a#$£.

I'm a thinking its got the "old scify" visual effect.. I feel a bit loopy.. need to rest me eyes.. 
If its good or not, yer riding... I'm waiting fer parts to come in... trickling may be a key word... 
Sneezles61

Yep, that's it, to a T. Dang,, was holding out hope that what was going on with mine was something different and therefore still reason to hope in finding a fix. But that is exactly how mine is acting so maybe it really is "normal" for these bikes. Man I hate to think that's true. I guess your bike did the same thing after the first rebuild too? Anyways, thanks so much for taking the time to make the video, really appreciate it. At least now I know we are talking about the same thing. Still gonna swap pilot jets when it gets here so will see what that does, or doesn't do.

Now granted it is not the same year bike and I don't know the long history it, but the '72 RT360 I briefly owned ran smooth as silk, just like a bigger version of my CT2 175, no surging at all when cruising. It didn't have the stock carbie on it, a previous owner had used a flange to spigot adapter and installed a different sized Mikuni. I'm not home at the moment but when I am I'll dig through photos to see if I can get more of a close up to show the size of the carb used. Wish I knew if it had any engine modifications but it's being enjoyed by someone else these days.

 

 

Hell fire ! I thought of Vanishing Point when it went squiffy and the two trees loomed up on the first bit of the vid.
All i can say is i'd like my RT 1 to run that well.
I do understand and i'm not trying to make little of it because it's bloody annoying .
It's almost like it's gasping for air and fuel .
What does the MX 360 go like anyone know?

perhaps the DT360 was a one year wonder because of these charming characteristics?

but I have a DT1E (71') and it does same, albeit 10X less, almost to the point of not being noticable 

Jack - the more you ride the bike the more you will get used to the weirdness, I think 

MX has a lower inertia flywheel, so unless other things were tweaked it must be a crazy ride

I have nothing insightful to add. I'll just suggest you've found out how 'they' do the dream-screen effect when Wayne and Garth slip into a dream on SNL or "Wayne's World!"

The MX360 is pretty sleepy down low and it takes a while before the power comes on.  From about 6000 RPM until close to 9000 it's moving pretty well.  If I felt like this old motor could withstand those kind of revs I might have played around with it more than I did.  That jug will probably remain on the shelf.

The ported and modified DT360A with the same pipe and carb pulls at least as hard as the MX360, but at a lower RPM.  Power comes on sooner and signs off right around 7000.  Nice and gutsy.

Since we're doing vids I wanted to throw my hat in too:



I know what you guys are referring to with the poor part throttle manners and inconsistent jetting. I hated it for months and months before I finally sorted it out. I believe it to be caused by several factors, primarily crankcase volume. Altering that alone did not solve the issue entirely but I didn't stuff the cases as much as I could have either. In conjunction with a larger, four petal reed block, modern carb, porting and a fancy ignition, it doesn't piss me off trying to ride this bike anymore.

Cruising at any speed is smooth and steady with no four stroking, no bucking, no surging and no pinging. The best example of this in the video is around 8 minutes and again toward the end. Most of the rest of it is marred by wind noise and the flapping of my gums.

Wish y'all could ride it. You would see what I mean. It runs properly, far better than stock.