Could you please help with acceleration issue 1985 NB50M?

[BillMckraken]

Hello,

It's me again. Not sure if anyone remembers, I had a 1983 Aero 50 I bought and was trying to get it going for reliable transportation. I got through all the problems and parts; also had a friend bend / straighten my rear wheel enough to drive (yay). I still have some wobble and vibration, but at least I can go somewhere. It seems to be running fine and consistent now, engine wise. I have had it up to 35, but won't try faster with the wobble, but I assume this means the engine is close to normal.

Okay, so to my question; if someone could offer assistance.
I have about 100 miles on it now after fixing everything. However, always mentioned a bogging when warmed up. This has become more defined now. Basically, when I took of.... it seeme fine until about 15mph. Then the engine boged (like a large loading) until 20mph then continued acceleration fine.
The last 2 times I drove, I noticed it seemed also to be bogging now also in the 5-10mph range, but much less.

I spent some time reading on the forum to see what it could be. I figured maybe the rollers were bad?

--Here's what I've done:
I removed the drive face and cleaned that out (seems there was a small amount of oil that leaked in) I hoped the oil might be it.
I removed the belt inspected, cleaned and measured it 14.5mm (still in spec) I have a new belt, but have NOT put on yet.
I removed the movable drive face (variator?) and there are about 3 - 1/8" wide small flat spots on each roller. Not sure if that would be it?
I cleaned all grease out of the movable drive face (according to what everyone says here?). I wondered if no grease would fix it...

So, I put the whole thing back together. The only change then was a clean case, clean belt, and no grease in movable drive face. I then went for a test drive (hoping this will help you guys). Now, it revs and takes off until about 5-7mph....then bogs heavily until 20mph. After that it seems just like before. As for top speed, I don't know, but it did still go 35.

I really hope that last ride will help you, but it baffled me. I called locally for rollers and I can only get 9.5gm unless I order (I measured mine at 13.2gm) and they are 16 x 13mm.


Question then, Do you think the whole bogging is the rollers and their bit of flat spots?
Why would removing grease make the problem more pronounced?
What all parts need to be replaced do you think?

Thank you for any help or info you can offer


EDIT - sorry, and the rear spring (driven face spring) is green in color....not sure if that helps. But I guess this all works together.

[maddog]

23 yrs ago my 87 aero nb50 did 66mph with the max options that were offered back then, i still own it - just PM me

[Bear45-70]

Ignore * puppy, no one on this planet has ever seen him with a scooter much less a fast one. Not even pictures of these supposed scooters.

Is this a 1983 or a 1985 Aero?

What weight rollers are you running as this is most probably not a fuel issue.

[richdavison34]

Careful bear, he owns your dreams.

I had a similiar issue with my 84 Aero. I cleaned my variator, removed the grease, and installed a new belt.....minimal difference.

Then I bought some new rollers. I got one of those variety packs from eBay that comes with a lot of different weights.

New rollers = new scooter...at least in my case. It changed everything about how it accelerates. It outruns my friends Ruckus now...well, to about 30mph at least.

My suggestion would be to get the variety pack of weights....experiment to find the weight that is right for you....then purchase some higher end rollers of that weight.

-Rich

[BillMckraken]

Hello,
Thank you for the responses!

@ Bear DOH! I have an 1983 sorry. For some reason I've messed that up when talking about the scooter. I dunno why my brain keeps inserting the 5.
Also,

(I measured mine at 13.2gm) and they are 16 x 13mm.

I assume it is all stock but 13.2gm is heavy! right?

@ Maddog 66mph!? wow I can't imagine how noisy that gearbox would be at 66!

@ richdavison34 Thank you for the information and for relating your experience also!

I have ordered that roller pack from Daywot (sp?), the one with all the sizes. I'll be sure to update when I get them. Since they only have 3 of each weight.....should I do 12 &13 for a bit lighter or should I do 12 & 14 for same total weight?

Thank you for the assistance and advice!

(ps.) - I do have the Boyesen reeds (psr-196) and they will fit perfect, but I won't install those and update that thread until I fix acceleration.

[richdavison34]

I ended up going with the 10g combo...11g and 9g mix.

[BillMckraken]

Hello,
Okay I FINALLY had time to check out putting new rollers on....and...well I'm still not sure what it is (maybe the back spring?)

To refresh a bit
-When purchased and got running it running right. Acceleration was normal Excluding a minor change (Take off boggier) after fully heated.

-About a hundred miles later (and within 25 miles from onset); I got a pronounced bogging (loading) in the 15-20mph range. Acceleration was normal before and after this mph. I still had the minor change when heated also.

-As mentioned I de-greased the roller/Var (noticed some flats) and re-assembled. (79gm total roller weight) So, the only change here was grease; however it did change the acceleration some. I mentioned it was now from 10-20mph, but while waiting to put new in; I was able to pin it more to 12-20mph loading. Overall, no grease seemed worse when it started to load the engine. Minor change (boggy) when heated same.

-With the new rollers I tried 11's & 12's (69gm total roller weight) and no grease. This time as I took off and got rolling, you hear a more rapid revving of the engine; though not huge "pull" difference. Within a second or two that faster rev-up went straight in to the heavy bogging / loading!? Also, I noticed it occurs right at the same point (appx. 12mph) and continues until 20.
Because this rev-up at the start is more noticeable, I'm assuming this is the rollers sliding out and increasing the diameter of the crank pulley (vari)? Also, it seemed as if these new rollers (in rev-ing faster) loaded the engine MORE even though at the same speed. Because of this, I was able to gain another possible clue. It seems from appx 12 - 15mph it is loading more, but from 15-20mph it seems to be slowly bogging less; Then from 21 on great acceleration. So, I'm assuming the actual culprit here is messing up in the 10-15mph range and 20 must be where the engine gets enough hp to run normal.

-Since it seemed to rev too fast and throw in the loading more, I tried the heaviest weights I got (13 & 14). These actually weighed .5gm over stock (79.5gm total weight). I was expecting to see it fixed or at worst the same as I started, but this one's different yet.
With these as you get rolling it still does rev-up fast like the lighter set, but seems to do it very close to that 12mph of death mark. So you get a loaded even rolling start, then a tiny burst of rpm and straight to bog city. Of course again after 20mph your back to normal. Also, when fully heated there is a little less punch (take off boggy) as noticed always.

The only other thing here I can think of since testing these new rollers is; you must come to almost a complete stop to "reset" that acceleration bog. E.G. if you slow down to 8mph and re-accelerate, better have some coffee until 20.

So I must say I'm still confused here. It seems Honda put as many variables as possible in this drivetrain lol. The thing that really sticks out to me at this point is that the bogging is occuring exactly at the same speed with all tests. Unless I need to use some drastically lower weight? However I wonder if I'll still just bog at 12mph no matter what weight they are.

I don't really know these that well but it does seem whenever the front pulley increases, it causes a reduction in the rear pulley diameter. Almost a little war going on there. It does seem maybe that in all cases it's "forcing" that back pulley to change to fast?

So, what do you all think? I'm wondering if that spring in the rear is bad (though seems fast to fail)?
For that minor punch loss when heated I'm guessing that maybe the clutch is slipping a tad when warm? or somehow doesn't bite as fast? not sure though that's tiny right now.

Thanks Bill