Ingram's 2005 Yamaha Zuma Build

[Zino]

9000 sounds real low with the weights you are running .
I found power at about 8500-9500 rpms for setting variator so you have rpms/horsepower to pick up

Did you take the restrictor out at the head of the pipe .
www.pedparts.co.uk/blog/yasuni-exhausts-how-to-derestrict

[ingram]

Sept 8, 2020 7:39:05 GMT -5 Zino said:

9000 sounds real low with the weights you are running .
I found power at about 8500-9500 rpms for setting variator so you have rpms/horsepower to pick up

Did you take the restrictor out at the head of the pipe .
www.pedparts.co.uk/blog/yasuni-exhausts-how-to-derestrict

Yes I took the restrictor out of the head pipe and then checked the silencer but since it was from Scootertuning there was no restrictor there which was nice. I will try my 5.1gr weights as well but so far the only big change after the BBK and before this pipe was the gears and I don't feel like my max RPMs are where they should be so I am going to check those just to see if something is up.

[ingram]

Just to update on my troubleshooting I took the gear cover off and checked the bearings and they all seemed fine but I replaced the one on the main shaft anyway with a brand new one. That didn't change anything and I was still getting the same max RPMs (9000) and speed (49mph).

I then started messing with the carb jets again and tried the 46 pilot jet with the 88 Polini main. This was too rich and I couldn't get more than about 35mph so I dropped to the 86 Polini and then everything was back to basically the same as the 44 pilot with 88 Polini main but max temps were overall a little lower (330 compared to 347) so I am going to stick with the 46 pilot and 86 main.

I then tried Malossi 5.1gr rollers and my max rpms went up about 400 rpms to 9430 but top speed was 48mph compared to 49mph for the 5.5gr rollers.

Finally I decided to swap back to stock gears and removed the 14/42 set and went for a test run still with the 5.1gr rollers to get a direct comparison. With stock gearing I hit 9790 max rpm at 47.2mph compared to 9430rpm and 48mph on 14/42 gears. So, the only change was going back to stock gears and I gained about 350 rpm and had basically the same top speed.

The fun factor is also much higher as I definitely enjoy the low down torque the stock gears are giving me.

I don't know why but it seems my Zuma just doesn't have enough power to push the 14/42 gears to their full potential and I am better off just using stock gears to get the increased torque.

Max results with 14/42 gears and 5.1gr rollers


Max results with stock gears and 5.1gr rollers


One day I might try 15/50 gears as I understand those would be about 20% increase instead of 30% for the 14/42s.

[aeroxbud]

Going 30% over stock is quite a lot. The 20% should be good.
I'm like you. I just have stock gears in the slider. It really takes off. But then I don't ride 60MPH roads, just using it in the city.

[Zino]

I did feel the drop in peak rpms by a few hundred for the same rollers after the gear swap .
All speeds I ran at probably 500 less rpms at each speed above 30 mph .

The craziest thing is you are picking up only 1 mph.
I picked up 6 mph and I had the same set up as you as far as kit with the weaker Next R pipe .

The stock gears do give the best take off .
I had to add the Top Perfomance torque driver to get as close to that take off .

I need to get away fast from Mean Dogs in the Country so 0-40 mph is most important Than going faster up top.

[ingram]

Sept 11, 2020 7:47:18 GMT -5 Zino said:

I did feel the drop in peak rpms by a few hundred for the same rollers after the gear swap .
All speeds I ran at probably 500 less rpms at each speed above 30 mph .

The craziest thing is you are picking up only 1 mph.
I picked up 6 mph and I had the same set up as you as far as kit with the weaker Next R pipe .

The stock gears do give the best take off .
I had to add the Top Perfomance torque driver to get as close to that take off .

I need to get away fast from Mean Dogs in the Country so 0-40 mph is most important Than going faster up top.

Yes very odd I am not seeing that 6mph gain. When you were running the Malossi kit was the exhaust port raised 1mm? I wouldn’t think that would be enough of a difference but maybe so.

[Zino]

I did raise it 1 mm it adds a few hundred rpms which would add a mile or two .

I did have to retune the weights to get full belt travel and good take off with the Tecnigas Next R .
I had the extra top end right away I just needed to work to get the takeoff back .

I found with the yasuni I can run lighter springs the yellows and a wider range of weights and get snappy take off and top end .

[ingram]

Hey guys I couldn’t help myself and went ahead and purchased a Polini CP 17.5mm carb along with jets, choke cable, and throttle cable. The carb bundle from dynoscooter included the 90 degree adapters for the cables and a stock air box adapter. As for throttle tube setup I got the NCY needle bearing grips from AliExpress for $25.

My initial thought on the jets is a 38 pilot and an 88 main but I can’t find many other posts on the Polini CP 17.5 and what jets worked for others. Do you guys think the 88 main is a good starting point or should I go higher like the 98 main?

On a separate note I put some sliders in last night and decided to take a look at my crank seal behind the variator and below is what I found. Is this a sign that I need to replace the crank seals or is this not to a point of needing replacement yet?

[aeroxbud]

It doesn't look like it's leaking yet. Did you put a smear of grease on the inside when you fitted it?

[ingram]

Sept 26, 2020 14:26:10 GMT -5 aeroxbud said:

It doesn't look like it's leaking yet. Did you put a smear of grease on the inside when you fitted it?

No that is the factory seal, I never changed them out when I got the bike so they are 15 years old but only 700 miles on them.

[aeroxbud]

At that age they would of definitely gone hard. I would replace them then. It's not that hard to do.

[Zino]

If your temps are good and hold a level temp you could hold off for awhile .
For Insurance on your next upgrade order just get ahold of the 17 x 1 flywheel puller and some seals .

For the seals replace them in pairs
You will need to get ahold of that fly wheel puller to get that stator off the other side .

To pull the seal just use a dry wall screw drilled into  it ,clean out by the inner bearings and then grease the inner edge of seal tap them lightly back in with pvc pipe until they are seated solid .

[yynnot]

Hi this is my first post I’ll chime in. I have an 04 with Athena 70 and dellorto 17.5 carb and I have a 95 main with 38 pilot and a leo Vince pipe. I just also installed 14/42 gears and my phone gps app clocked in at 59mph. I think it might be off by a couple mph still though. Your top speed I would think should be able to break 50 mph no problem. You might see some more with the new carb.

[ingram]

Sept 28, 2020 12:17:39 GMT -5 yynnot said:

Hi this is my first post I’ll chime in. I have an 04 with Athena 70 and dellorto 17.5 carb and I have a 95 main with 38 pilot and a leo Vince pipe. I just also installed 14/42 gears and my phone gps app clocked in at 59mph. I think it might be off by a couple mph still though. Your top speed I would think should be able to break 50 mph no problem. You might see some more with the new carb.

Thank you for the info and yes I am hopeful the carb will help. Seeing that you are using a 95 main on the Dellorto 17.5 makes me think I should start with a 98 on my Polini CP 17.5 and go down from there instead of starting at 88. As everyone has told me so far it's always better starting out rich anyway and going down.

[aeroxbud]

Definitely go richer than you think. Both the sport kits I have fitted. I have started around 100 main. It's very easy to tell by just a quick run if it's very rich.
If it's struggling to rev out I go down about four sizes. Once nearer two, or even one size at a time.