RZ350 Super Motard

[Smoker]

Yeah, I agree.

On this bike, and the streetfighters, I'll need to run a wire to the front wheel for the speed sensor. The plan is to run the front pressure wire with the speed sensor wire. Still won't be able to run it parallel with the brake line off the caliper, but I'll do what I can to make it look good.

[Smoker]

Was thinking about this, so I found a pic to look at.

I may have made a mistake with my carb tubing. I connected the bowl vent tube and the bowl overflow tube with a "Y" connector.



Should be okay, unless the overflow tube drains fuel beyond the "Y" connector. Then, I think fuel could be sucked up through the vent tubing.

Will try to redo with both vent tubes into the same "Y" connector, and both overflow tubes into the same "Y" connector.

My guess is that the vent tubes also need to go to a vented catch can, in case the bike falls over.

[OldTZracer]

Yes - I think the vent & overflow lines should be separated. Keep in mind that air may need to move in both directions...

[JonW]

If the carb vents suck, they could pull fluid up towards the overflow?

[Smoker]

Top of the float chamber showing the 2 vents that are open to air.



Why are there two vents, instead of one? I assume when the bike leans left, the left vent can get blocked with fuel- but the right vent will be open. With this setup, fuel should continuously flow by gravity into the bowl.

When landing big jumps the fuel can slosh up into both vents at once, causing the engine to bog. I think that's why Kehin came out with Quad Vents on larger PWKs.

The standard Keihin PWK 28 has two vent tubes, one for the left vent hole and one for the right. The KX100 Keihin PWK 28 has two vent tubes for the right vent hole and ZERO vent tubes on the left. The left vent hole is blocked.

The KX85/100 PWKs are setup for half the displacement of my engine. Because these carbs will be flowing a lot of fuel, my guess is it would be a good idea to open up the left vent.

Red and yellow are open to the right vent. Blue is blocked. Green is where I could put another matching port and have a one-off PWK 28 Quad Vent. Will at least be a Tri Vent.



Never heard of the blocked vent before. Only heard that the KX PWKs are such a bargain. Now, I know why they're cheaper.

[Smoker]

If the carb vents suck, they could pull fluid up towards the overflow?

Not sure about that, but the vents could definitely get blocked with fuel.

If the lateral vent tube and the quad vent tube (same side) are connected into a common tube, I think it will defeat the purpose of having a second vent.

Fuel in the bowl will definitely drain out of one of the vent tubings on each carb if the bike falls on it's side.

[Smoker]

From the Keihin website:
"Quad Vents: Eliminates post jump bogging from fuel plugged vent passages."

I guess since air is moving out of the vent passages, fuel can get into them, causing the engine to bog.

Besides opening up the left vent passage, sounds like it may be a good idea to install a quad vent on the left side of the carbs.

The other thing is, it may not be a good idea to run the vent tubes into a longer tubing, or into a catch can with a filter. Was thinking about Poiseuille's law- i.e., longer tube = more resistance to flow.

I've talked to Roger in the past about installing oversize fuel bowls and using a fuel pump on some engines so the bowls don't run dry- especially with smaller carbs.

[Smoker]

Getting jigged-up for some Christmas day mods.

Need everything to be level and square.

[Smoker]

Jig worked, so I drilled out the blocked vents on both carbs.

[Smoker]

And don't forget that having an own decent TIG box in the garage should be on every mans bucket list!

Pulled the trigger today and ordered a nice quality TIG.

Still need to order quite a bit of supplies and an argon setup.

Not tapping out, yet....

[85RZwade]

Great to see you post again, and congratulations on the welder purchase! I've been looking at TIG setups myself recently...$$$

[Smoker]

Great to see you post again, and congratulations on the welder purchase! I've been looking at TIG setups myself recently...$$$

If you're looking, I should pass this on.

The TIG I bought was $1,000 below MSRP at Lowes Hardware. Didn't see that low of a price anywhere else.

I got a Lincoln Precision TIG 225.

[Smoker]

Don't want to get my hopes up yet, but I'm trying to get enrolled in the Vocational Welding program at the local community college.

Only taking 25 students, and I already missed the priority registration.

Fingers crossed.

[85RZwade]

Changing careers, or for your own use?

[MK]

You may find weldingtipsandtricks.com interesting.

When I got my TIG box back in 2007, I watched and followed that a lot.
And don't be shy to try & error without a dedicated training. Experience doesn't hurt before attending a class as it tells you what's to be asked.