Yamaha TZR250 refresh

[busa1300]

i bought one, doesn't flow enough. I did a pressure drop/flow test on it, flowed less than a 6mm id hose, which is what feeds the fuel t. I have a few ideas what im going to do, but i do appreciate it. 

3MA-24510-00-00

[m in sc]

now THATS interesting. However, i cant access the bottom of the tank when its on so would always be on reserve or ON, so id have to modify it. its a shit design, not going to lie.

 

[SoCal250]

The replacement fuel cap arrived early so I replaced that yesterday. I went for one of the better repop units instead of OEM or the really cheap Chineseium stuff on eBay. Seems to be well made, fits nicely and looks good. Even came with a large rubber gasket under the mounting bracket which my original did not have. And it was about 1/3 the price of OEM.





Now I'm stuck in a holding pattern waiting for parts.
I had decided to go with an OEM Suzuki petcock as opposed to the repops available on eBay, and with my luck it is now backordered (despite the availability displaying as '3-4 days' when I submitted the order).
Shipping Estimated Date:7/31/2023-8/7/2023
Once that is here I can eliminate the inline filter and shut-off valve that I installed previously and then replumb new fuel hose

The "To Do List" (revised and getting shorter)

• Petcock - replace with Suzuki unit
• Fuel hoses - replace & re-route
• Carbs - check & adjust after running
• Coolant - flush and replace #2 (after running)
• Trans oil - oil change #2 (after running)
• Paint - clearcoat solo seat cover
• Chain - re-check slack after running (30-40mm)
• Fire-up & road test
• Clean & detail

[SoCal250]

I haven't posted an update in a while so I thought I'd add the latest news. The Suzuki RGV petcock arrived, as did the hoses I had ordered from McMaster. I got some black thin-walled hose that Mark had mentioned previously and some Tygon, thinking I could use some of each for the different sections or just go with the one that worked better.

A few weeks ago (Aug 11) I finally found the time to install it. I pulled the entire fuel hose assembly out so the previously installed inline filter and inline shut-off valve were deleted. This allowed for a much cleaner hose install and more direct plumbing with shorter runs and fewer turns. Decided to go with the yellow Tygon since it is less prone to kinking than the thin wall black. Since all the hose is now the same diameter (3/8", 8mm) I also replaced the OEM T-fitting with a brass 3/8" piece because the OEM Yamaha part is 10mm in and two 8mm out. I have a Suzuki OEM 8mm T-fitting on order (now backorder) but it's been a month and no signs of it yet.



The Suzuki OEM petcock has an 8mm brass outlet.
One interesting fact the petcock is configured for an optional dual outlet, it just needs to be drilled and tapped for a 2nd outlet fitting.
I'm sort of considering modifying the petcock someday so I have two outlets. Then I would be able to run hose directly to each carb and delete the T-fitting.


RGV250 petcock installed.


I'm now getting fuel to both carbs but it still will not start. It only runs for about 5-10 seconds on the rear carb. After kicking it 30-40 times and also trying to bump it on the street I was exhausted and gave up. Need to do some further investigation to see what the issue is an verify there's spark on both cylinders.

The "To Do List" (revised and getting shorter)

• Petcock - replace with Suzuki unit
• Fuel hoses - replace & re-route
• Carbs - check & adjust after running
• Coolant - flush and replace #2 (after running)
• Trans oil - oil change #2 (after running)
• Paint - clearcoat solo seat cover
• Chain - re-check slack after running (30-40mm)
• Fire-up & road test
• Clean & detail

[m in sc]

i def have petock envy. looks great

[Acme Moto]

Russ, I had the same problem with my 3xv. It was difficult to start and would not stay running. Checked everything multiple times and finally found the lower intake manifold was cracked. Replaced with a new one and all good!

Sad story connected to my 3xv. A good friend/collector had two 92' 3xv5's and one was blinged out with all the the period correct Sugo and Daytona trick bits. He gave me the stock one as a gift as I wrenched on all his bikes for him and he felt it was appropriate to give it to me. His wife had been battling cancer for years and it became terminal. He was starting to sell bikes to pay for medical bills so I gave the bike back to him so he could sell it. A month later he died of a heart attach at 50 years old and a month after that his wife passed. He was a good dude and I miss dearly. Sorry to hi-jack your thread!

[SoCal250]

Russ, I had the same problem with my 3xv. It was difficult to start and would not stay running. Checked everything multiple times and finally found the lower intake manifold was cracked. Replaced with a new one and all good!

Sad story connected to my 3xv. A good friend/collector had two 92' 3xv5's and one was blinged out with all the the period correct Sugo and Daytona trick bits. I gave me the stock one as a gift as I wrenched on all his bikes for him and he felt it was appropriate to give it to me. His wife had been battling cancer for years and it became terminal. He was starting to sell bikes to pay for medical bills so I gave the bike back to him so he could sell it. A month later he died of a heart attach at 50 years old and a month after that his wife passed. He was a good dude and I miss dearly. Sorry to hi-jack your thread!

Thanks for the tip Max, I'll look into that when I have the time to get back at it. This thing has always started in 1-2 kicks since I bought it back in 2004. Guess I shouldn't have mothballed it for so long.

Really sad story! Sorry for the loss of your friend.

[SoCal250]

Had the autographed solo seat cover clear coated at Lanzini Body Works. Very happy with the result, he did a great job and even touched up a couple tiny scratches in the red paint.  Found out Mitch the owner is also a 2-stroke nut and owns a mint Y/B RZ350 and a restored JT2, both of which were in his shop.



Haven't had much time to work on the remaining items for this bike, but at least one more thing can be crossed off.
The "To Do List"

• Petcock - replace with Suzuki unit
• Fuel hoses - replace & re-route
• Carbs - check & adjust after running
• Coolant - flush and replace #2 (after running)
• Trans oil - oil change #2 (after running)
• Paint - clearcoat solo seat cover
• Chain - re-check slack after running (30-40mm)
• Fire-up & road test
• Clean & detail

[SoCal250]

Finally got around to revisit the stalled out TZR recommissioning project.


Pulled the carbs again and went through them. I found black goo in the bowls, which may be from the new bowl gaskets breaking down? It's not from the tank or fuel hose since I'm running yellow Tygon. Strange.
Ran the carbs through the ultrasonic and reassembled. After cleaning them up, the gaskets seem fine and the goo did not reappear after several days.

Rear carb






Front carb




Flushed the coolant and refilled with fresh.

I was starting to suspect I might have a bad coil or pick-up since one cylinder wouldn't fire previously, but after testing with a meter all were confirmed in spec and good.

Confirmed both cylinders are getting fuel and spark.

Worked on getting the bike to fire and run right. At first it wouldn't start and would barely run on one cylinder (same issue I had last year). After some tweaking of the cables and slide settings it now starts and runs on both cylinders, but still needs work. I even pulled the carbs again to double check the pilots were clear and verify float height. All were good. I'll do further tuning after the new air filter foam arrives.

Rode it around the block a few times just to piss off the neighbors. It's loud! (TZ-Mike 150mm silencers) 
So fun to be able to ride this bike again. It's such a blast to ride. I can't wait for it to be done and fully road worthy!

[m in sc]

does yours have the solenoid air jet?

[SoCal250]

does yours have the solenoid air jet?

Not that I'm aware of, as there are no electrical leads on the carbs. Maybe the "compensators"? There are 2 devices the manual (at least the English translation from Japanese) calls compensators. Each one is remote from the carb and connects with a hose to a nipple on the front of the carb above the bellmouth. I have not attempted to pull these apart yet or inspect them.

parts # 3 & 4

[m in sc]

yeah, thats what i was thinking about. was just curious.

[SoCal250]

Found the shop manual page with the compensators/solenoids. Attached is the translation

[m in sc]

yeah, i know that can be controlled with a zeeltronic as well for nth nth degree tuning. awesome if you have a dyno and lots and lots of time. clever setup indeed.

[busa1300]

Basically a street legal TZ...
The 3XV series is such a cool final goodbye to the Yamaha 250 line of street bikes.