2021 TBR7 Purchase

[kyle]

Originally Posted by Nospark

Renarg - What's your elevation? I'm 600ft in Milwaukee. Did your bike come with the PZ30 carb? If so, can you share source for the jets you purchased?

Tbr7.com fuel system page has all the jets and a chart with jetting from different users at different elevations too!

[Nospark]

Kyle, Thanks for the link to the guide. I was following this guide but, found it on my own after considerable searching. It's a good resource. It appears I have some hardware fasteners that are different than than those noted in the guide and/or larger qty. So far, I have not found any defects or poor assembly from the factory.

[Nospark]

Ordered the PZ30 carb upgrade and jets. That should be plenty of adjustment to get me going out of the gate. I can always upgrade to better carb if I make other upgrades such as exhaust.

[Thumper]

Originally Posted by Nospark

Thumper, Have you confirmed front sprocket on yours yet?

No. I haven't pulled the cover. My use is mostly off road. I like the stump jumping ultra low gearing. Some people gear these things really tall so that they can go 70mph. I'd rather ride my Bandit GSX 1250 at higher speeds. It is made for it, and has the power to do it comfortably and confidently (understatement!). I hear some scary stories about wobble and shaking over 60 on dirt bikes. It takes a stiff frame, stiff wheels, and a tight/strong triple clamp to go fast confidently. Knobbies add to the instability, but I swapped out the dual sport tires for knobbies.

If I change it, I will be getting a slightly larger rear sprocket. Then 2nd gear will be a crawler, and 1st gear will be the creeper!

[Thumper]

Originally Posted by Nospark

Ordered the PZ30 carb upgrade and jets. That should be plenty of adjustment to get me going out of the gate. I can always upgrade to better carb if I make other upgrades such as exhaust.

Wait a minute. What is a PZ30 carb upgrade? Am I missing something here? Didn't your bike come with a PZ30 "clone" carb? My son's new TBR7 did. All it needs is rejetting. We rejet it this weekend. It came with a #88 main jet, and we replaced it with a #108. The pilot jet was a #36, and we replaced it with a #38 and set the pilot screw at 2.5 turns (the carb is dry, haven't finished the build). We also shimmed the needle with a couple of teeny washers (~1.5mm). These are pretty modest changes, but we are not changing airbox or exhaust.

What are you going to do with your original PZ30 clone carb? I must be misunderstanding the "PZ30 carb upgrade".

[Nospark]

Thumper PZ30 clone. See link, https://www.amazon.com/dp/B073SVJF2Q...SIN=B073SVJF2Q

It's basically the same as factory carb. I'm confident you're approach, jets and adjustment will result in excellent results. I may end up following your lead if I don't like this carb when it shows up. With this carb yYou don't have to slot the bowl screws to disassemble like the factory carb and I believe you can adjust needle position using notches in needle rather than washers. Regardless, my understanding is this carb still needs to be rejetted. I'll start with #108 or #110 and 36 pilot. I plan to leave the exhaust stock for now but will remove the restriction in the air box inlet design.

[Thumper]

Originally Posted by Nospark

Thumper PZ30 clone. See link, https://www.amazon.com/dp/B073SVJF2Q...SIN=B073SVJF2Q

It's basically the same as factory carb. I'm confident you're approach, jets and adjustment will result in excellent results. I may end up following your lead if I don't like this carb when it shows up. With this carb yYou don't have to slot the bowl screws to disassemble like the factory carb and I believe you can adjust needle position using notches in needle rather than washers. Regardless, my understanding is this carb still needs to be rejetted. I'll start with #108 or #110 and 36 pilot. I plan to leave the exhaust stock for now but will remove the restriction in the air box inlet design.

I guess the new carb is cheaper than buying a dremel. But I always love an excuse to buy an new tool, and slotting the headless screws is easy. The slots on the needle simplify needle height changes, but isn't as flexible as varying washer thickness. It's also simple to do... the slide spring holds down the spring clamp too. Did you find the jets I linked (sent a pm)? AliExpress has main jets too. If you can, slot the screws and see what jets are in your original carb. My son's came with 88 main and 36 pilot. And what is in the new PZ?

[Nospark]

Yes, Found the jets and ordered them. I'm pretty proficient working on motor stuff. Just new to the China bike and scooter thing. Nice to get more use out my metric stuff than SAE for a change I have the tools I need to modify the stock carb and still may do that if I don't like the one that shows up. I'll let you know what I have in the stock carb and new one as far as jets when I get to that. I tried to replace front sprocket last evening and ran into a problem. I'll post that under my "chain" post.

[Bruces]

The issue with some of the carbs was that we didn’t have a source for the jets ,some used mikuni jets ,some keihin ,some used something completely different .Most of them have been figured out now ,,but back in the day we would take a carb apart and possibly wait a few weeks to get the jets ,so the answer was to order a new carb with known jets so it can be ridden right away ,and no need for a Dremel for the people who didn’t have one .

[Thumper]

Originally Posted by Bruces

The issue with some of the carbs was that we didn’t have a source for the jets ,some used mikuni jets ,some keihin ,some used something completely different .Most of them have been figured out now ,,but back in the day we would take a carb apart and possibly wait a few weeks to get the jets ,so the answer was to order a new carb with known jets so it can be ridden right away ,and no need for a Dremel for the people who didn’t have one .

I would not recommend buying a carburetor to get new jets. It is real unlikely that it will come with the jets you will need. Each bike has different intake resistance, and exhaust resistance/back pressure. It is Winter here, so I was OK with waiting for the jets. Just order them. You will need them for a new carb anyway. You won't like the carb if it isn't jet right
The OEM carb will need rejetting too. Either way, a couple of weeks with imperfect carb, if you are riding in the snow right now (!) won't hurt. Think about it, lots of people ride with improperly jet motorcycle carburetors for their entire life!!