Slow Low - mid range acceleration

[Nicolas]

Hi,

My stock 1998 zuma bogs on the lower end and mid range and takes a while to climb to the tops speeds. It idles fine. It maintains speed just fine. The air filter is clean, the spark plug is new, the tranny oil is new, I use fully synthetic amsoil 2-stroke oil. Basically, everything is fine and un-tampered with.

One thing though: when I got the scooter, it ran really well and accelerated much faster : especially when I rode with my girlfriend (now it bogs at about 25mph and creeps up mega slowly, especially on hills). The only thing I really changed were the settings on the carb, because I read somewhere that the proper setting was 1.5 to 2 turns out for the A/F screw and it used to be out atleast 5 turns (I didn't want to seize the motor or anything so I hanged it to the stock "recommended" setting)...

I also took the pipe off in order to spray paint it and it was practically impossible to put the pipe back on because I could never get a proper angle to turn the bolts in... there's a bunch of pipes/bars in the way (from the steel frame). It took me a while to get it on properly, but I finally did and it ran fine. Nonetheless, there was a small leak where the pipe and motor connects and some sirupy carbony stuff would gradually build; nothing serious, even a mechanic told me so. How do you folks get it nice and tight???

How do I get rid of this ever so boring slow acceleration... I'm thinking its an A/F screw problem... but right now it is at 1.75 turns out.

What do you think, have any of you ever had a similar problem?

Nick

[lakercr]

Hi,

My stock 1998 zuma bogs on the lower end and mid range and takes a while to climb to the tops speeds. It idles fine. It maintains speed just fine. The air filter is clean, the spark plug is new, the tranny oil is new, I use fully synthetic amsoil 2-stroke oil. Basically, everything is fine and un-tampered with.

One thing though: when I got the scooter, it ran really well and accelerated much faster : especially when I rode with my girlfriend (now it bogs at about 25mph and creeps up mega slowly, especially on hills). The only thing I really changed were the settings on the carb, because I read somewhere that the proper setting was 1.5 to 2 turns out for the A/F screw and it used to be out atleast 5 turns (I didn't want to seize the motor or anything so I hanged it to the stock "recommended" setting)...

I also took the pipe off in order to spray paint it and it was practically impossible to put the pipe back on because I could never get a proper angle to turn the bolts in... there's a bunch of pipes/bars in the way (from the steel frame). It took me a while to get it on properly, but I finally did and it ran fine. Nonetheless, there was a small leak where the pipe and motor connects and some sirupy carbony stuff would gradually build; nothing serious, even a mechanic told me so. How do you folks get it nice and tight???

How do I get rid of this ever so boring slow acceleration... I'm thinking its an A/F screw problem... but right now it is at 1.75 turns out.

What do you think, have any of you ever have a similar problem?

Nick

I doubt the problem is with your fuel setting. When is the last time you changed the belt, and how old are the springs in the clutches? If the springs are original, I'd suggest replacing them with new Yamaha springs, and put a new stock belt on it at the same time. Springs lose their tension over time (I replace my snowmobile springs every year), and the belt is a wear item that needs periodic replacement. The problem you are describing are the exact symptoms of tired clutching components. Did you notice the clutch seems to engage at a slighty higher rpm (this would be a subtle observation), or a slight loss of top end?

Often people think that bogging is a fuel issue, and sometimes it is. Quite often though, it is a clutching problem. I read on another thread that guys are putting on new belts and having issues with them slipping, and that they need to ride them for awhile to 'bed' the belt in. If you go with a new belt, here's what I always do:

Wash the sides of the belt in hot, soapy water, while scrubbing them with a scotch-brite pad. Rinse the belt off and let it dry. Take another clean, dry scotch-brite pad and clean up the surface of the drive clutch. When these belts are made at the factory, a thin film of the mold-release remains on the belt - that's what you're scrubbing off.

[Nicolas]

I am a complete newb. Would I be able to change the belt and springs myself or do I need fancy tools? If not, should I go to Yamaha, or would a local bike mechanic be able to do this relatively simple job?

Will Yamaha know what I mean when I ask for clutch springs, how many do I need (sorry I don't have a clue what these look like or how they work... clutches)? How much do they cost?

My scooter has about 7000 miles (11000+kms), would this be a typical time for replacing springs/belt? Would this be the time to get a high perf clutch, even though I run a stock scooter?

Yes, my top speed seems to be reduced. Also, the throttle resistance seems to be a little weak when the scooter is hot after a longer drive (I don't know if this is normal).

[lakercr]

I am a complete newb. Would I be able to change the belt and springs myself or do I need fancy tools? If not, should I go to Yamaha, or would a local bike mechanic be able to do this relatively simple job?

Will Yamaha know what I mean when I ask for clutch springs, how many do I need (sorry I don't have a clue what these look like or how they work... clutches)? How much do they cost?

My scooter has about 7000 miles (11000+kms), would this be a typical time for replacing springs/belt? Would this be the time to get a high perf clutch, even though I run a stock scooter?

Yes, my top speed seems to be reduced. Also, the throttle resistance seems to be a little weak when the scooter is hot after a longer drive (I don't know if this is normal).

You don't need fancy tools to do this. Have a look in the 'how to' section of the site - I'm pretty sure there are instructions there for changing variators, springs etc. You'll have to decide if you're comfortable with doing the work yourself.

Yes, I'd say you are due for springs/belt. Your dealer will know what you're talking about (at least mine would) if you tell them you want to replace the drive/driven springs and have a new belt installed. Springs are cheap, and I would expect a dealer to be able to complete the work in about an hour.

You would see no benefit from a high performance clutch.

[05redzuma]

yeah you expect, but they probably charge 3 hours labor, which i understand, they have to make a living. but it will probably be about 2-3 labor hours. which most shops are about 60-80 bux an hour, and probably around 50 dollars worth of parts. Call ur local dealer and ask them what their labor rate is, and get a price on all the parts u need.

[lakercr]

Nicolas, call your dealer and get a price, then decide if it is worth it for you to attempt yourself.

There is nothing difficult about doing this work. If you know how to post pictures to the forum, I'm sure that myself or many others can walk you through the parts that might be confusing. The bet way to learn about this stuff is to get your hands dirty...

[xraydino]

Sound like your torque driver spring is getting weak. It might be a good time to replace everything in the tranny. Belt, rollers, torque driver and clutch springs should be about $70. The belt is the most expensive at around $30-$40. All tranny work is pretty easy if you have the right tools. Especially the torque driver assembly ( a second set of hands makes it much easier ) . I wouldn't listen to your machanic friend about the air leak. Air leaks at the exhaust manifold on two strokes lead to blown cylinders.

[05redzuma]

dang where are ya'll gettin belts for 30-40 bux, i ordered a stock yamaha belt(i know not the cheapest but i dont want kevlar and cant find any Bando's that arent gonna take a month and 1/2 to get here) and that thing was 68 bux!!!

[Axton]

I got a bando from provo with my stage 1.

http://www.provoscooter.com/shop/product_info.php?cPath=33&products_id=80&osCsid=f9295daa6fa8ba3b4511ad7185bc1f0c

[Nicolas]

Do you think an average motorcycle mechanic with experience will be able to change the belt, rollers, torque driver and clutch springs if I get them for him? Would I be better off with a small motors mechanic? How many hours of labor should I expect for such a job?


(The reason I ask is that the local dealership has a bad reputation and has ripped me off previously)

Also, I forgot to mention that I switched oils before the scooter started performing poorly. I used to use this : http://www.worldsbestoil.ca/2-cycle-oil-synthetic-hp-injector.php and now I use this: http://www.worldsbestoil.ca/2-cycle-oil-synthetic-interceptor.php . Both should be fine, but I thought I'd ask the pros (that's you) :).

[Jack B]

If you were to do the work yourself it would take longer but a experienced person should be able to do the job in a hour or less. It is not hard to do but for a person with no experience it will take longer. With the how to,s and help on the forum it is probably be something you can tackle.

[jaafallon]

Nicolas linked to two oils but neither of them is the 2-stroke oil Amsoil recommends for our application. This chart http://www.worldsbestoil.ca/2-cycle-chart.php recommends the "Saber Professional" 2-stroke. have you tried that?

jim

[Nicolas]

Nicolas linked to two oils but neither of them is the 2-stroke oil Amsoil recommends for our application. This chart http://www.worldsbestoil.ca/2-cycle-chart.php recommends the "Saber Professional" 2-stroke. have you tried that?
jim
It appears to me that this oil is meant to be pre-mixed... am I missing something?

Since I have to change my belt, rollers, torque driver and clutch springs, would now be the ideal time to get the stage one kit : in the sense that this would probably fix the problem aswell?

Provo's stage one (http://www.provoscooter.com/shop/product_info.php?cPath=35&products_id=146&osCsid=42aa67fc4a9b95d9cd6eef7e94bc1035) includes a Leo Vince ZX exhaust, an Athena Variator, Roller Weights and Clutch Springs.

I found one on another site that comes with with a Tecnigas NEXT R, Malossi Variator, Roller Weights and some clutch springs. Plus the Malossi Variator comes with a torque spring.

Is the torque spring what Xraydino called a torque driver???

So, should now be the time to upgrade since I am facing problems most likely related to the tranny parts being warn out? Also, if I get one of this kits, should I get a kevlar belt or a regular one?

Would I get a non-biased answer if I asked what kit is recommended?

[jaafallon]

Since my scooters automatically inject the correct amount of oil, I believe I can simply add the Amsoil and it will be metered correctly into the engine. Otherwise (.nuked..) Bye, bye, Baby! If I'm wrong on this I'd sure like to know in advance.
jim

[mikal]

Nicolas, to your question about the torque driver spring, yes. I believe he was refering to the torque driver spring.
And yes, if you feel like spending the money for the parts, stage 1 is relatively simple to install, with little to no loss in reliability and you'll see some performance gains.....probably a little less than 5+ on the top end, with a small gain in bottom end response.

BTW, I recieved the Next R, Malossi Multivar, and ect... stage 1 from provo, although I haven't been there in a while to check.

[Lennox]

Nicolas,BTW, I recieved the Next R, Malossi Multivar, and ect... stage 1 from provo, although I haven't been there in a while to check.

Nicolas, the "Pre-bug" Zuma stage one lists the Leo pipe. The "Bug-eye" has the Technigas.

[Nicolas]

Mine is a 1998 (as stated in post 1), so I don't think I am mistaken.

My main concern is that maybe I should try to make it run fine before I upgrade... I need for you guys to be sure this will fix my current slow acceleration and get me to acceleration equal to someone upgrading with an already fine zuma (which mine is not).

[speedy_scooter]

He mentioned the Tecnigas was on another site. I think I know where he's talking about and it comes with the Tecnigas instead.

[mikal]

My bad, you caught me, I skipped ahead. :)