aero NH80 clutch roller weights

[SlowestPoke]

First of all let me say that I really appreciate this forum. You've taught me much without knowing about it.

I'm working on a beat up 84 aero 80 that I think is the greatest thing since sliced bread. I've cleaned up the engine and replaced the head and cylinder. The only thing I've altered from spec is a larger main jet. It now bogs at 3/4 throttle. It feels like accidentally shifting to fifth gear in a car, and learning a bit about it it seems like a plausible explanation is that the cvt is shifting up too quickly.

I was wondering if anyone with experience changing to lower weight rollers on a 84 NH80 would share with me what you learned from it. I'm 270lbs and considering changing to 12g weights.

Any advice?

[bonesv]

First of all, how long have you run it with the new cylinder? There should have been a "break-in" period to seat the rings to the cylinder. If you have just run it without seating the rings, then you may have some issues. That being said, I have heard that the NH80 likes a 92 main jet, as long as you maintain the stock airbox and the air filter is oiled properly. I have also heard that the 2-stage Boyesen reeds help quite a bit, but it sounds to me like the carburetor may need a proper cleaning and going through. There is a help section here for that if you have not yet.
Also be sure the vacuum choke is correctly "plumbed", meaning the hoses are not leaking or dis-connected. You would not want to ride it with the choke "operating". You could also find help from our old friend Bear45/70 over at http://motorscooterguide.net/Forum/index.php
He is the Aero "king". Once the above is addressed, then one could venture into the roller weights and such.
Welcome and, Happy Trails!

[treekiller]

I did the roller weights when I upgraded to the JASAL Top racing variator, on my NH50 with a 70cc kit. my stock weights were like 12.5 grams, I ended up using the lightest set that shipped with the variator 9 gram. and it still shifts before the peak of the power band.

I would also try a slightly lower needle setting, if you upgraded the main jet it might be running rich in partial throttle, since you did not modify anything else. it's easy to go one clip lower if it gets better go another grove, if it gets worse then go back 2 grooves. but I doubt it's running leaner with the larger jet.

While you can drill out the hole in the center to lighten up the weights, (slide the plastic off before putting them in a vice) I'd try the needle first since it only takes 5 min to do and you don't need to remove the carb off the bike.

[SlowestPoke]

Thanks for the replies I haven't noticed any problems with the cylinder, Bonesv, but I'll keep an ear out for any odd noises. I upgraded the main jet to a 92 but still need to get the reed.

I tested my theory this weekend by removing and degreasing the variator then removing half the weights to see how it ran. It seemed to work as intended. Full throttle didn't bog at all. Man, you could definitely tell that the the weights were too low at 8g. The top speed was around 30 and it was truly winding up. I don't have a tach or anything like that so I don't know what the engine speed was.

I decided to order the 13g weights. I've read that for every gram reduced the engine speed required to move the variator the same distance increases by ~500rpm, so I went conservative first with a 1500rpm change. I got them in yesterday, so I'll probably pop them in and test that soon. I think you might be right about the needle setting treekiller. It seems to be running a little rich since I changed the jet. I'll give it a try.

I'm gonna paint it and finish the tuning over the next couple of weeks (If it doesn't snow too often). Thanks for the input and I'll be back with some pics and stats!