Yamaha RazZuma SPC: Spare Parts Concoction

[birdman]

Looking good. I can't wait to see what you get out of that corsa once it's all dialed in! Great work thus far hellish!

[hellish100]

I am enjoying my 'shelter in place' by spending more time in the garage. 

I found a spare fuel pump/valve and have been meaning to install it on the Razz. I used to have the fuel line gravity feed straight to the carb. I was never crazy about that idea should the float/needle fail and have my tank drain out!

Anyways, the Del 21 has a vacuum port right after the slide. I believe most people use it for oil injection, however it does give enough pulse to power the fuel valve. I was thinking I would need the fancy stage 6 intake for the vacuum port but thankfully not!




Here you can see where the vacuum line is plumbed.





Lastly, I'm still trying to tune this thing. It really doesn't like the kart style airbox. It pulls well without it but I'm not going to mess up an expensive cylinder by not running a filter. My CHTemps are still low from what I'm reading. My max so far has only been 215. When idling it cools off to 180.

I know I'm rich. I lowered the needle, and went from a 90 main jet to an 88. That's the lowest I have apart from a 70 main.
The forecast is rain for the next 10 days so I probably won't have another chance to take it out for a while. Anyways, here's another pic!

[hellish100]

Anyways, small but really cool update on the Razz.





I was breaking down my Aprilia Scarabeo and did a double take on the mounting of the front caliper. The bolt spacing looked close enough to try mounting it on the Bug-eye forkleg of my Razz.

It fits!

If you are looking for a caliper upgrade, the dual piston Aprilia caliper fits. Plus it looks like I can change pads without removing the caliper. ( If you are familiar with Brembos, you'll see the similarities. The pads are held in by a pin that can be removed and the pads can be slotted in/out from the top of the caliper. ) I swapped the line and master cylinder along with it. The lever feel is greatly improved but it will need more road testing and new pads for me to put full confidence in it.

[hellish100]

Alright y'all. I am stuck.
Trying to jet this is proving to be a pain in the butt!

Polini Corsa
C16
Del 21 with Kart style filter
Top Performance Variator 
Stock Clutch and Contra

It'll start up and rev but it will not take WOT. It almost felt like a broken reed but inspection showed no cracks.
I double checked compression and got 140.
Re-torqued the head.
CHT reads 215 but it feels like it's not getting enough fuel. 

Current Jetting:
42 idle
95 Main

Could the the stock springs and Contra be to blame?
Has anyone tuned the carb with the front pulley removed to remove it as a variable?
I know it wouldn't test the engine with a load on it but I'm battling something here and I don't know what it is.

[birdman]

Maybe still too rich. It sounds stupid and unrelated, but check all your grounds make sure you have solid engine grounds or it could cause all kinds of problems.

[hellish100]

Good call on both.
I am running 32:1 premix but I think that is too much oil. I’m going to step up to 40:1 next. I see a lot of guys running that safely here.

It will not get on the pipe or really just clear itself out so I’m thinking I’m still too rich and my ratio is not helping.

I’m running a BR8es NGK, and will go to the hotter 7 to see what difference that makes.

Lastly, I finally ordered 4.6 and 5.4 gram rollers. I currently have 7 grams. Also coming are a set of clutch springs and medium contra spring. I’m thinking that combo will get this thing revving like it should.

[fullblast]

Apr 24, 2020 8:17:20 GMT -5 hellish100 said:

Let’s see if I can be of any help here


Virtually all the calipers from minarelli engined 50cc will fit except those scooters with 10 inch wheels and some older versions like the Malaguti F12 up to ‘96 or ‘97. They are interchangeable. The rubber brake line I see in the picture is unfortunately really bad. Very spongy feedback, gets even worse when the brakes heat up. Many stock braking systems have better lines (F12, Aerox/Nitro and in fact many Yamaha/Minarelli 50cc). Yes, you can change the pads without removing the caliper, even if it’s just two bolts.

As someone else previously mentioned, make sure you run a grounding cable from a part of the chassis that is not painted and the carter. Also, sounds stupid but make sure the gold washer beneath the main jet is installed correctly.
With your jets you can’t be too far off. I had first starts of similar setups with 45-90, needle (probably you have a W16) at the second line from the top, 50 valve and mixture 1.5 open.
For “housekeeping”, also check the atomiser. In the standard PHBG versions (I am not familiar with the black version like yours) Dell’Orto started installing AN262 atomisers that are more indicated for 4 stroke engines. Try installing an AU262 if you can get hold of it, which is designed for 2 strokes.


I would start off with the 4.6g rollers. Don’t be surprised if you need to put lighter rollers though. Medium contra spring is also a good choice in my opinion, which one did you get?


Let us know!

[hellish100]

Very helpful! I’ll check the atomizer soon. I removed the gold washer, but still have it and will throw that back in. I really need to check my grounds again. Thank you for emphasizing that!

I ordered a malossi yellow contra spring. All the parts should be here by Friday which means I’ll be annoying the neighbors again this weekend:)

[fullblast]

Good stuff! I’d probably install, as a start, clutch springs engaging at 6000/7000 rpm.

Did you try the scooter with the 88 main in the end?

Also, if she still misbehaves, try uploading a video if you can!

[hellish100]

Parts came in yesterday and were promptly installed when work ended.

4.6g weights
Yellow Polini clutch springs ( second to highest strength in the box )
Yellow Malossi contra spring

Also inspected were my grounds. It turns out I did not have a single ground to the block/carter. I whipped up a ground for that.

Tomorrow I will mix up some 40:1 and give it another go.

[fullblast]

Outstanding!

[hellish100]

Need to add pics of GPS but yesterday I hit 56.8 mph!
Max CHT 291. I think I can come down a little bit more on the main jet.

[hellish100]

Enjoy!

[hellish100]

It’s been a while since the last update. A lot has changed at my work and I got a new toy ( of the 4 wheeled variety).

The razZuma has been through a few changes as well.

I swapped out the build motor and am saving it for something else and I took a few other things off it too. I have been working with my Venice as it’s already got the big brakes, built motor and slicks.

Long story short, I no longer desire to continue developing the razZuma frame. With that said, I’m going to be listing it for sale shortly.

Thanks to everyone that’s been watching this thread. I still have the Venice and the spree! I’m not going anywhere.

[Sum-azn-kid]

Nov 23, 2020 23:43:40 GMT -5 hellish100 said:

It’s been a while since the last update. A lot has changed at my work and I got a new toy ( of the 4 wheeled variety).

The razZuma has been through a few changes as well.

I swapped out the build motor and am saving it for something else and I took a few other things off it too. I have been working with my Venice as it’s already got the big brakes, built motor and slicks.

Long story short, I no longer desire to continue developing the razZuma frame. With that said, I’m going to be listing it for sale shortly.

Thanks to everyone that’s been watching this thread. I still have the Venice and the spree! I’m not going anywhere.

Aw I liked the razz build. Do you have a thread for your Venice build?