More DeReg Questions from Newbie [Archive] - Provoscooter.com

pdxjim

09-12-2005, 11:22 AM

I just got a new 2003 Vino Classic 49cc last week, and love it for trips around the neighborhood and am planning to use it to commute the 5 miles to my job. However, even if I stay mostly on secondary streets, there are places where I'm going to get run over if I can't occassionally get over 30mph, and going up hills at 15mph isn't so great, so of course I'm considering the derestriction mods. What I want is an increase in speed and maybe pickup. What I don't want is a bike that my wife is going to hop on and accidently pop a wheelie and wipe out in the street. I've seen the detailed how-to instructions on this website, but still have some concerns that I would appreciate if someone could put at ease...

Questions...
1. I'm still in the "breaking-in" the engine stage. Should I wait until after?
2. Because the bike is still on Yamaha's warranty, maybe I should wait a while anyways.
3. It sounds like the exhaust mod is the most immediately productive and sounds straight forward to do, but...
A. Does this increase the noise? Right now, it's amazingly quiet, sort of like riding a sewing machine.
B. I'm seeing references to having to re-jet the carb after the exhaust mod. I'm not too keen on having to go down that path. Though I'm good with tools and despite having done it often, I really don't enjoy tinkering on vehicles that much.
4. Is the variator mod really worth the trouble? It sounds like it only adds a few more mph with the Vino 49cc.
5. Lastly, obviously the variator mod won't, but will the exhaust mod adversely affect the engine in any way? I don't have a lot of experience with 2 cycle engines, but changing the exhaust back-pressure seems like something the engineers didn't have in mind.

Hopefully I've asked a few questions others haven't yet...

Thanks for any and all replies...

XPS1210

09-12-2005, 12:37 PM

Questions...
1. I'm still in the "breaking-in" the engine stage. Should I wait until after?

2. Because the bike is still on Yamaha's warranty, maybe I should wait a while anyways.
3. It sounds like the exhaust mod is the most immediately productive and sounds straight forward to do, but...
A. Does this increase the noise? Right now, it's amazingly quiet, sort of like riding a sewing machine.
B. I'm seeing references to having to re-jet the carb after the exhaust mod. I'm not too keen on having to go down that path. Though I'm good with tools and despite having done it often, I really don't enjoy tinkering on vehicles that much.
4. Is the variator mod really worth the trouble? It sounds like it only adds a few more mph with the Vino 49cc.
5. Lastly, obviously the variator mod won't, but will the exhaust mod adversely affect the engine in any way? I don't have a lot of experience with 2 cycle engines, but changing the exhaust back-pressure seems like something the engineers didn't have in mind.

Hopefully I've asked a few questions others haven't yet...

Thanks for any and all replies...
1. why wait to upgrade till after the break in? as you then just finish one break it to start another break it (per the book anyway). I personally don't agree with a 600 mile break in.

2. If you want yamaha to fit it if it dies... DO NOT mod on it till the warrenty expires!

3. I'd imagine it's a HAIR noisier... your making the beginning of the exhaust pipe the size of the pipe instead of the size of the exhaust tip (that's about the size difference from the restictor to the pipe) (make since?)

4. can't say I ride a derestricted zuma...

5. the zuma is basically the same motor (the tranny is shorter on a vino)... but the zuma comes without the restrictor in the exhaust... so IMO, the designed it to not have the restrictor cone, then added it later to meet the 30 mph laws of some US states

sooznd

09-12-2005, 12:47 PM

Some dealers will even do the de-restrictions for you and still honor the warranty.

Besides there is very little that can go wrong with the scooter while it is under warranty anyway

I highly reccomend de-restricting and going 40 mph ::handleba

cycleNdave

09-12-2005, 10:08 PM

absolutely...

http://members.cox.net/dw.morris/police.gif

pdxjim

09-13-2005, 02:13 AM

I appreciate all the encouragement from everyone about this, but no one has yet addressed my question about having to re-jet the carb. Am I going to have to do that if I dereg the exhaust?

sooznd

09-13-2005, 06:37 AM

In most cases it is not necessary to rejet if all you do is the exhaust de-restrict. When you change pipes, you may need to re-jet.

As Jered mentioned, the noise increase is negligible, I wasn't even sure if there was one or not. But the increase in speed is NOT negligible. 7-9 mph for less than an hour of your time & no expense......What could be better?:yippy:

These scooters were orignally designed to run without any restrictors, so you are eessentially running the scooter contrary to the intent of the original enginneering if you ride with the restrictors on it. The restrictors are added on to meet moped laws in the US. The Japanese Vinos are not restricted.

pdxjim

09-13-2005, 10:12 AM

Well, thank you all for the comments and encouragement. The engineer side of me is completely at ease about doing this and looking forward to the results, though I still plan on holding off a bit just to make sure no warranty issues crop up.

Unrelated question: does anyone have any idea why Yamaha felt they had to change the turn signals for units sold in the US?

sooznd

09-13-2005, 01:04 PM

some DOT regs -I think the blinkers are supposed to be a certain width apart, but not sure

Either that or Yamaha USA had a bunch of those ugly stalk blinkers left over from some motorcycles and wanted to get rid of them. ;)

speedy_scooter

09-13-2005, 01:06 PM

Just to meet DOT specs.

pdxjim

09-15-2005, 04:08 PM

I've done some more thinking about this exhaust dereg thing and I think I get it now...mostly...
...restricting the exhaust is similar to restricting the carburator air intake (like a throttle plate does)...the less fuel-air mixture that passes through, the less power and RPMs the engine achieves. What puzzles me a bit is the post from King Vino that insists it's quoting information from YMC itself, that the carb jet is reduced in addition to the exhaust flow on units for sale in the US. Which raises the question...if a throttle plate can open and close without the jet having to get bigger or smaller, why does the jet have to be increased when the exhaust is restored to its designed throughput, unless what he says is true, that the jet on US models is reduced also. I live in Portland, Oregon, which is about 150 ft above sea level. I guess I can keep an eye on the spark plug, and if it looks like it's running too lean, I'll have to re-jet. Which raises another question...where does one get one of these non-standard size jets if needed?

gjtomli

09-16-2005, 09:42 AM

I think Yamaha will still honor the waranty... why dont you call you dealer and ask? Mine came from the dealer unrestricted and they honor the waranty.

hobolurkin

09-16-2005, 09:45 AM

Mine had a bigger jet added by the dealer during my complimentary (read: included in price) derestriction of the exhaust and variator. It runs exceedingly rich according to my plug reads. I'm at sea level (or just above, i suppose, since I'd be wet right now otherwise). Others in this area have derestricted their own scooters without changing the jetting and are running a perfectly nice a/f mix.

Honestly, I wouldn't suggest that you worry about it. In fact, I've begun thinking about how i can lean out my a/f ratio a bit while staying in the safe zone. It's hard to get information about it, however, since "leaner" seems to be a bad word on most scooter forums ;)

Bart

pdxjim

09-24-2005, 07:20 PM

Hey, I just did my variator dereg. It was pretty easy, really, once I got those #&%#$#! #3 Phillips screws off. The factory really had those torqued on. (When I saw a screwhead wanting to round even with my #3 driver, I ran off to Harbor Freight and picked up an impact screwdriver for $6.99, which did the trick with a tap from a mallet. I'm sure I'll use it again during the next century :)).

Verdict?
I wouldn't say it goes any faster, but it's definitely perkier in the low and mid-range which is really nice.
Ok, I'm liking this bike more and more. Too bad I waited until Fall to get it. Would have been nice at the beginning of Summer.

Next weekend I'll attempt the exhaust/jet dereg.

o_o

Bernie

09-24-2005, 11:21 PM

Jim,

The variator mod only gets you a mile or two top end. The pipe deregulaton will show you about 8 or 9 mph increase on top and even more pep.

Mine got me to 38 indicated.

Nice. Last low cost performance increase you'll see. :ll

Zuma_Man

09-25-2005, 12:09 AM

Just wanted to add, another 1 for the books, my vari wasn't restricted with a washer, nor my pipe, but I can see where they removed the one in the stock pipe, just wanted to notify that about the 2005 zuma, I think they keep the restrictions on the Vino, why? I have no clue, maybe because the tires? Not that it matters anymore with my afterMarket vari and pipe.

Zuma_Man

09-25-2005, 12:10 AM

if you de-reg your stock pipe, you can perhaps hope for a 4-5mph increase at most, not an 8-9mph increase in speed, unless you live on top of a mountain and drive downhill all day.

Greymane

09-25-2005, 05:58 PM

I just dereged my new Vino after 300 miles, and where before I was running at 30 mph on flat, it is now doing 39 mph. On steep hills (>10% grade) I was barely going 15 mph and now can easily do 30 mph. I have yet to remove the governor. I'll do that when I get my kevlar transmission belt.

Zuma_Man

09-25-2005, 08:15 PM

well, i might stand corrected then, I know Vino's do better with upgrades that zumas, which i hate it, because I dont like the way vinos look or care to buy a "buddy" seat. But that must have been one heck of a restriction for you to be able to get 9mph out of it, bravo!

cycleNdave

09-26-2005, 09:18 AM

just by de-reg'n my exhaust i went from 28mph to 40 no prob...and after vari 45mph..

Dragonnoodle

09-27-2005, 01:32 PM

Your only other mod is a new vari?

speedy_scooter

09-27-2005, 02:59 PM

I'm thinking he was talking about derestricting the variator by removing the restrictor washer.

cycleNdave

09-27-2005, 09:40 PM

yeah...speedy...just de-reg'n variator by removing washer..

Dragonnoodle

09-28-2005, 05:22 AM

Ohhh.

sooznd

09-28-2005, 06:48 AM

just by de-reg'n my exhaust i went from 28mph to 40 no prob...and after vari 45mph.. cycleNdave -that's a fantastic increase after doing the variator mod. I only reaped a 1-2 mph increase. I did the exhaust mod after 300 miles, too went from 29-30 mph to 37-38. After the vari I get 39- 40.

Are you at sea level? I am at high altitude (5000 ft) and think the Vino may be slower due to that.

cycleNdave

09-28-2005, 09:54 AM

i'm only 400 and something above sea level..

pdxjim

10-25-2005, 05:54 PM

Okay,
I'm really trying to understand these carburetors and jets and exhaust restrictions and so forth, and I'm think I'm getting it, but now I know enough to have another question:

I understand why having to re-jet is likely if the exhaust is de-reg'd, but why just the main jet? I thought that really only affects 3/4 to wot. Won't the increased air flow require a complete rejetting, i.e, pilot, needle, slide?

speedy_scooter

10-25-2005, 06:25 PM

Actually thats a great question. The main reason that only the mainjet needs to be replaced is because when going around at 1/4throttle the motor isnt really leaned out too much. Now, when you start opening up that throttle to say 1/2-3/4 then it gets too lean for safe running when an upjet is needed. Now, not all dereg's need to be upjetted, the same thing goes for people who get stage 1's. It's not always needed but for some it is. I hope that helps you.

pdxjim

10-25-2005, 06:47 PM

Yes it does. I wasn't sure what the relationship was between opening up the exhaust flow, throttle position, and mixture, but it sounds like you're saying that under lower throttle the airflow isn't increased that much at the exhaust port. Graphs of this stuff would help. Know of any?

speedy_scooter

10-25-2005, 06:49 PM

I dont know of any but I'll try to make one here in a minute. Its basically that though, at lower rpms the airflow isnt increased as much as when your going WOT.

jarlo

10-29-2005, 02:36 PM

Looking forward to that graph.

I actually have a related question.

I tried to remove the exhaust restricter. But didn't have the right tools so it was difficult removing this http://img482.imageshack.us/img482/8347/exhaust27hu.jpg

I did take this bronze looking washer thingy out, http://img482.imageshack.us/img482/9739/dscf00258jr.jpg

And put the exhaust back together.

And to my surprise, it made a significant difference. The acceleration was 100% quicker and I am reaching close to 40, whereas I barely made 30.

I am actually very happy, because now I can keep up with traffic!

Any ideas why this happened? It shouldn't really have increased airflow that much? Or was the exhaust funny and when I took it apart and put it back on, it was corrected?

Also there is some leakage in the pipe, and apparently the previous owner drilled some holes in the back of it. So it is loud. And actually louder now that I changed it.

Thanks for all your help. This is actually fun stuff!

pdxjim

10-29-2005, 03:43 PM

I'm not no expert here, but it sounds like you removed the exhaust port gasket instead of the restrictor, which basically created a big leak. Although this would increase the air flow resulting in a power boost, and increase the noise, the exhaust gasses are now leaking out the side of the exhaust port junction instead of through the exhaust pipe, which will probably lead to running too lean, overheating, engine problems and/or damage. Since you did get a power boost, I'm inclined to think this is exactly what's happened.

Any input from the pros here?

By the way, I haven't done mine yet, but I've got the same kind of ultra heavy-duty restrictor welded in place. How are people getting this particular one out of there?

sooznd

10-29-2005, 05:56 PM

Jim you are correct-that is the exhaust gasket & needs to stay in there or you will have an exaust leak & risk ruining your engine.

You will need to grind out the conical piece blocking the exhaust--I just sat on the ground with the exhaust pipe between my feet and drilled it out with the largest drill bit I had, round & round & round & round--took a while, but it finally came off---if you can find the weld points, even better--just drill on them and the whole thing might fall out.
Be careful not to drill through the pipe, though.

speedy_scooter

10-29-2005, 07:11 PM

Its easiest if you know someone with a Dremel. With a Dremel you can go right through those welds, if not, then the drill is the best way.

cycleNdave

10-29-2005, 07:22 PM

a dremel works best...with this bit..used for steel...just set exhaust on work bench and carefully grind down the tack welds...it will fall out.

pdxjim

10-29-2005, 07:41 PM

jarlo

10-30-2005, 01:04 AM

I've got a Dremel, cutting wheels and some grinding bits. Sounds like this won't be that tough if I ever get around to it. (Still waiting on jets... )

Hey jarlo, you'd better replace that compressible gasket, Yamaha p/n 4KN-14613-00-00, price about $4. Probably can't reuse the old one if you pried it out.

Yup. Figured I messed something up! HA!

I am just going to order the Stage 1 kit right now. I was going to wait a bit, but I might as well get the whole deal, now that I screwed up the exhaust. I'm a bit wary of my mechanical skills, but I know that I can at least put the new pipe in.

Hopefully my moped can last the few days it takes for the parts to get here! I only drive the 6 miles (round trip) to work....

Thanks guys! What a great forum!

sooznd

10-30-2005, 06:59 AM

Jarlo
you should be able to put the exhaust gasket back in until you get your stage 1. My gasket fell out when I was de-restricitng and almost every other time I had to rmeove my muffler for changing the rear tire and stuff. No need ot get a new one unless it is damaged, just slip it back on, so you no longer have a leak.

jarlo

10-30-2005, 12:21 PM

DOH! :dunce: It got thrown away already!

Do you think I risk alot of damage if I ride it a few miles a day this week?

speedy_scooter

10-30-2005, 12:29 PM

If its leaking a whole lot then riding it that way will cause you to run lean which can lead to siezure.

jarlo

10-30-2005, 03:58 PM

I guess I won't be riding until I get the Stage 1 kit! _o

Thanks for the help, I'm glad I asked, before I risked damaging my motor!

I'll get my scooter fix by doing the tune up and cleaning.

pdxjim

11-13-2005, 09:44 PM

Okay, everyone. I've finally done my exhaust dereg. I upjetted the carb to 67.5 with a Mikuni VM11/22 jet, will keep an eye on the plug for good measure, and frankly I'm impressed. In fact, I'm a little scared. The slightest twist of the throttle and I feel like I could do a wheely. Yikes. But I got what I wanted, which was more speed and more acceleration. I just wasn't prepared for that much more acceleration, especially so touchy.

jarlo

11-13-2005, 10:01 PM

More gasket troubles!!

Got my Stage 1 and decided to put the pipe on. It was a rough fit to line up the brackets and the cylinder to the exhaust. We finally adjusted the bracket to only use it at two points.

We thought it was okay, just loud, and I rode home. But this morning I noticed it wasn't flush, so I loosened it and saw that the gasket was torn. I slid it back in and got everything flush, but I feel the air puffs...

Anyone know where I can get a new one? Or should I just try and seal the leak with a little JB weld? I don't know if that's the right idea, but I have the feeling I won't be changing the pipe again!

speedy_scooter

11-14-2005, 08:30 AM

JB weld wont stand up to the heat. Try getting a high temp silicone that is at least the 600degree kind. Put that on both sides of the gasket and put the pipe back on. Let the silicone dry for about 16-36hrs before you ride it.

jarlo

11-19-2005, 07:57 PM

Just got a replacement gasket from provoscooter, and put it on. It is so much quieter! A dramatic difference! (It was only 5 dollars, if someone needs a new one.)

I also replaced the spark plug and it wasn't white at all, it was a good tan color, which means that despite the leakage, it wasn't running lean.

Only thing is the gasket is a bit bigger than the openings, so the exhaust and the cylinder aren't flush. But I'm not sure that matters because there is no leakage (I plugged the pipe silencer to test and it turned off when I did it). I rode around a couple miles then see if it rattled looser and it didn't. Though one side can tighten more than the other, I'm leary to tighten it much further.

pdxjim

12-02-2005, 04:38 PM

Okay, one more question on this topic.....

I've just learned about how on 2-stroke engines the exhaust system is specially designed to bounce the gasses back at the exhaust port to pre-compress the next combustion mixture (something like that). If I cut out the little cone Yamaha put in there (which I already did) don't I alter this effect? What's the impact? I did get a big boost in power which is great, but what about this "bounce-back" compression thing?

My mileage has seemed to have gone done some. Is this why, or is it just because I'm utilizing more power now?

(Actually, I'm still not going over 30mph, but I am accelerating a lot quicker, which is great. I'm also not bogging down going up hills. I would not want to put it back the way it was.)

Lennox

12-02-2005, 05:08 PM