16" Xingyue Gear Question By gross392 (Read 1,298 times)

[gross392]

I have a Tank TR 16, also known as a Xingyue xy150t. It has 16 inch wheels and is a pretty nice scooter. I have a free flow filter on it with a little bigger jet. That is all I have done to it. The scooter has enough power to get me going ~55 (GPS) whether it be on a flat or slight incline. The only thing that limits me is the RPMs. When i get going 55 or so the rpms are approaching just over 8k on my tach. I know the tach is not that reliable but my engine sounds like it is really turning.

I have heard that the 16" wheel scooters have different gearing in the final drive behind the clutch. I have never taken off the clutch, but I am wondering if any one else has or knows the specs on these gears? Also, if there is any way to swap out gears so I can lower my RPMs a bit so I can cruise 60 without my engine screaming.

[gross392]

I also have a stock 123mm variator with a large belt. I think it's 906 mm. I will have to double check. The engine number is XY157QMJ-3 which has little to no info that I can find. I have talked to scrappy about BBKs before and he has had hardly any experience with this type of an engine...

[Alleyoop]

Have you tried heavier weights,
For every gram up or down you can change your RPMS by 500-600 so going up 1 gram or a combo of 1.5 grams more per weight you can do the 55mph at around 7300-7500rpms, which most 150s max horsepower is around 7500rpms and you will be right therei.

You then can take the Clutch off drain the tranny and take the Clutch shaft and plate off and count the teeth on the Short Shaft that the Clutch turns and count the teeth on the Big gear that the Short Shaft teeth mesh with. Then you figure get the gears you want.

TALLER GEARS IN THE TRANNY:

Changing the gears behind the Clutch to taller gears for more top end speed:

If you Change the Small Shaft that the Clutch turns by 1 more Tooth AND the Big Gear that the Small Shaft Turns by 1 Less Tooth that Drives the Output Shaft that turns the Wheel or (Sprocket with a Chain) you will gain about 4-5 mph more. For every number of teeth changed you can expect about 4-5mph more Top End Speed.

Here is how to change the Gears:


Here is were I got mine:
www.partsforscooters.com/Welcome?search=hoca+gears

Alleyoop

[gross392]

I have seen these before which made me want to switch them in the first place but Sprocket was telling me that the 16" wheeled scoots have a different gear reduction. Maybe a double reduction or something. These 16" wheel scoots are a whole different animal haha.

My intuition would tell my that at 8k rpms my variator almost has to be pushed out as far as it can go...

[Alleyoop]

Actually the variator get pushed out all the way at around 40mph then as the engine cranks faster it is just turning the Variator Faster which in turn turns your rear wheel faster.

So putting in heavier gram weights to lower your rpms will also give you a few more mph top end. One way to test that is mark your Variator and see how far the belt climbs, mark it like the picture run it at wot and then see how much of a mark you have left.

Well you won't find out what it has back there unless you take the plate off. Nobody really knows people are just guessing SO YOU CAN BE THE PROJECT LEADER on this one and see what is back there. I would say they have the same gearing but with lower gearing to slow the sucker down. It is not a big deal to do just going to cost you new gear oil back there.
Alleyoop

[gross392]

Yeah thats what i figured I would do. I am at college right now so i'm kind of limited on my tools right now.

I have done the variator thing before too. I found that I was about a quarter inch away from the edge of the variator when I was using the stock belt. I did some calculations and calculated that in order to get to the edge I would need to go from a 906 belt to something ~20mm longer if I remember correctly. I found a 918mm belt online somewhere and I installed it hoping it would still get to the bottom of the clutch and the edge of the variator. I again marked the variator and it is maybe a little bit closer to the edge but I figured out that the belt was not getting all the way to the shaft on the clutch. I had to go back to the 906 belt.

This motor uses something like an extra long case motor since 250s usually use 906 or 918mm belt so it's all sorts of goofy.

[Alleyoop]

Many believe that a longer belt will get them more top end because it will climb higher on the Variator. But what they do not realize is because it is longer it may NOT pull the belt as far down on the CLUTCH pulley as possible where you will get the most speed. Therefore actually looseing top end even though the belt went higher in the Variator pulley.

So stick with the correct belt and get some heavier weights, that 1/4 inch left on your variator is 3-4 mph loss on your top end. With the Heavier weights it will drop your rpms to where you want them as well as get you a little more top end. WIN WIN for you.
Alleyoop

[kiwiscoot]

How about machining the variator boss down say 3mm/ 3/8" and play with 3 X 1mm washers?? that may close up the variator a tad and you can go back to standard.
I see the Dr Pulley variator comes with a shorter boss and washers to tune the boss length. Maybe longer belt and shorter boss??
I have no experience with this, but my wifes Xingyue is the same and seems to have enough power to cope with higher gearing. I went heavier sliders, but it did not do much, That extra unused variator face just asks to be used.

[sprocket]

Good to see you back Kiwi ;-)

[Alleyoop]

Dr Pulley Variator USED to be cut down their BOSS, NOT anymore. I investigated that last year and posted the response. But some kits still send the washer since they must have millions made. If you use the washer without measuring the BOSS to the OEM you have you will find out pretty quick because you will loose a lot of top end.

Also cutting down the BOSS I personally have already done that. I ordered just the BOSS and had it cut down 1/16 and the only thing it did was put to much pressure on the belt because now the alignment with the rear pulley was not as true. It created a lot of heat and even lost top end. I still have the cut down boss, I was the Science Project on that one
Alleyoop

[kiwiscoot]

sprocket - always been here, I just had nothing to say and I said it.

alleyoop - did not think of that.