Just Ordered a Brozz 250

[dubbya1986]

Originally Posted by goat67

Tonight I took the carb off and adjusted the Air Fuel Adjust on the bottom of the carb. PITA it is not slotted it is a half circle head.

I am not sure how far out I went but I am thinking around 2 - 2.5 turns.

The needle rod does not have slots so I ran to the hardware store a got two flat washers and put them under the clip.

It starts easier now and idles better. Seems more even up to 1/2 throttle when revving it.

I pulled the plug and it looks pretty white running way lean I am thinking.

It is raining so no road test

Getting better every day.

As far a breaking it in someone here said they where going to keep it under 3000 or 4000 RPM until 500 miles is that really necessary?

I have cracked it a few times to just see what it is doing at higher RPM did not stay at any high RPM for long.

I run it up threw the gears hitting probably 5500 doing it by ear mostly.

Comments?

I adjusted my fuel mixture screw out some to see if the bike would start easier and it did, but now now the bike it cutting out under over half throttle...I guess mine may have been fine to begin with, now I can't seem to get it back to where it was. All I did was adjust the screw out some, but I can't do it while it's running since the screw is impossible to get to without taking the carb part of the way off. I am going to order an easy adjust screw so I can do it with the carb attached since I can't get it right now.

[MOTOXtreme]

That screw should only effect slow / low throttle. Half or more is using the main jet. Maybe something else is going on?? Did you pull the needle for any reason? *Just thinking maybe its not seated 100%??

[dubbya1986]

Originally Posted by MOTOXtreme

That screw should only effect slow / low throttle. Half or more is using the main jet. Maybe something else is going on?? Did you pull the needle for any reason? *Just thinking maybe its not seated 100%??

Suggestions on how to check it? I didn't open up the carb besides unscrewing the top cap to try and be able to turn the carb over easier to be able to get access to that screw. I screwed it back on when I was done.

[MOTOXtreme]

I would just go over your work (I'm sure you already have). My low needle was dang near slam shut. But, I only opened it up by about 1/2 to 3/4 of a turn and it made a world of difference. You could start there (out 1.75 turns from closed) just to see if it is somehow effecting you.

[dubbya1986]

Originally Posted by MOTOXtreme

I would just go over your work (I'm sure you already have). My low needle was dang near slam shut. But, I only opened it up by about 1/2 to 3/4 of a turn and it made a world of difference. You could start there (out 1.75 turns from closed) just to see if it is somehow effecting you.

When you say low needle, are you talking about fuel mixture screw on the bottom I already adjusted? Could me unscrewing the spring loaded cap and taking it out to be able to move the carb screwed things up?

[dubbya1986]

Originally Posted by MOTOXtreme

I would just go over your work (I'm sure you already have). My low needle was dang near slam shut. But, I only opened it up by about 1/2 to 3/4 of a turn and it made a world of difference. You could start there (out 1.75 turns from closed) just to see if it is somehow effecting you.

I double checked and the needle is still clipped and attached 100% to the throttle cable. I also made sure it was fully inside the hole before I screwed the cap back down. I am at a loss as to why the bike cuts out when you stab the the throttle. It didn't do that until I messed with the fuel mixture screw. It has great throttle response at less than half. Is it possible I just need to change the main jet? I really don't see why it would just start doing this. I had to have done something else when I messed with the mixture screw, I just don't know what.

[MOTOXtreme]

Yup, I was referring to the PITA one on the bottom and I agree with you in that it dont make since. You MAY have just got a small particle of debris worked loose in there from the factory or when you had the throttle needle out. Unfortunately ours have the tamper proof screws you have to dermal off but you could remove those, blast it with cleaner in all the jets and reassemble. But if your going that route you may as well re-jet it.

**Speaking of jetting our Brozz....I will be jetting mine and dont mind learning from others. So please, anyone who does tell me (us) what jet is best for factory setup.

[goat67]

Info I have and parts I am going to use on the carb.


Jets https://www.aliexpress.com/item/10pc...608.0.0.V9M2hN

Carb Kit
http://www.ebay.com/itm/291807976434

Another Article on the PZ carb
http://www.ccwthariders.com/uploads/...ing_manual.pdf

And An Article on how to tune / jet the carb

https://www.duncanracing.com/TechCen...arbJetting.pdf


And A tutorial from CSC
https://www.cscmotorcycles.com/Articles.asp?ID=294

[Ariel Red Hunter]

Originally Posted by goat67

Info I have and parts I am going to use on the carb.


Jets https://www.aliexpress.com/item/10pc...608.0.0.V9M2hN

Carb Kit
http://www.ebay.com/itm/291807976434

And An Article on how to tune / jet the carb

https://www.duncanracing.com/TechCen...arbJetting.pdf


And A tutorial from CSC
https://www.cscmotorcycles.com/Articles.asp?ID=294

I think the tutorial from CSC is the most helpful. What I call the pilot jet, Keihin calls the slow jet. What some people call the idle jet I call the idle mixture screw. The main jet is a main jet. I would hold the main jet holder firmly, so that just the main jet unscrews. I would not go through the float and float valve routine. Just change the main jet, and the pilot jet. And put in the multi groove needle, with clip. You don't need to worry about needle taper or thickness with the five grooved needle. When I do this on an Amal, Bing, Del Orto, or Mikuni, I follow a simple system. I start by setting the carburetor where it should be. Idle mixture screw out 1 1/2 turns. Needle in center slot. Now, with the engine idleing, turn the mixture screw back and forth until engine reaches highest idle rpm. I think (from what I read) that the Keihin uses an fuel bleed idle screw. As opposed to an air bleed idle screw. If I'm right, that means the farther you turn the idle mixture out, the richer the idle mixture. So if you have to turn the idle mixture screw out more than 1 3/4 turns, the pilot jet is too lean. Now the slow jet controls the mixture from just above idle to 1/4 throttle. The needle controls the fuel mixture from 1/4 throttle to 3/4 throttle. BUT IT IS DOING THIS BY REGULATING THE FLOW FROM THE MAIN JET. So, while the ultimate test is the plug chop, for now you don't need to go that far. Once you have the correct slow jet (pilot jet), there will be a hesitation when you get above 1/4 throttle. Change up on main jets until there is no hesitation. When you get past five hundred miles, then you can do a plug chop. Perhaps by then, you will have found the kill switch on the handlebars. LOL

[goat67]

Thanks ARH

I will keep you posted as to what I do to the carb. I will follow your advice.

And as far as the kill switch there is not one on the right side and not one on the left it is really weird that this bike does not have one.

Anybody have any ideas to incorporate one?

[Kipper1012]

Hey goat
how did you adjust your pilot fuel mixture screw ? Mine looks like it only has a flat spot on one side of the head instead of a slot for a flathead screwdriver. Is that how yours is ?

[MOTOXtreme]

I removed my carb and adjusted with pliers out about .5 turns(ish). Made a world of difference at idle.

[Azhule]

Originally Posted by Kipper1012

Hey goat
how did you adjust your pilot fuel mixture screw ? Mine looks like it only has a flat spot on one side of the head instead of a slot for a flathead screwdriver. Is that how yours is ?

2 (main) things you can do...

1: Buy the specialty tool(s) for that...

Maybe something like this will work ???

https://www.rockymountainatvmc.com/p...el-Screw-Tool-

or

2: Carefully remove the mixture screw, and saw a nice straight line in the middle of the thing so you can turn it with a flat head bit

[MOTOXtreme]

If I stick with this carb rather than switching to a Mikuni I may just get this. http://www.ebay.com/itm/192103828884...%3AMEBIDX%3AIT

I already ordered jets for this one so I may as well use them.

[Kipper1012]

Originally Posted by MOTOXtreme

I removed my carb and adjusted with pliers out about .5 turns(ish). Made a world of difference at idle.

Ok Hmmmm I was trying to avoid removing it. To get it adjusted as accurate as possible it needs to be running.

I wonder if any aftermarket tusk thumb screws would fit