RZ350 Hybrid

[gman]

Sounds like your making all the right moves Phill. Curious. Are you using the original airbox or other carb air filters? Also what carbs are you using? Rz350 26mm mikuni's? The bike is coming along very nicely. Great work.

Sent from my SM-G900I using Tapatalk

[phil1rowe4]

Thanks gman,
I'm using the standard vm26 mikuni carbs with wet foam pod filters.

It's idling nicely with the 25 pilots fitted. I also increased the mains to 250s. The plugs are still quite wet but I'm assuming that's to be expected when its not running at speed and under load. Its been 30 years since I last ran a 2 stroke!

I'm currently making an oil pump blanking plate with a housing cap to accommodate the oil pump shaft, so I don't have to remove the shaft from the side cover and can refit the pump easily later.

Chain is now fitted and tank paint stripped and liner done so once I get some undercoat on the tank, I'll be able to ride it around the block to test it under some load.

[phil1rowe4]

Hi,

Since I'll be running pre-mix until I can get the oil pump serviced, I wanted to make a blanking plate that incorporates the oil pump shaft, so I don't have to drop all the fluids and remove the clutch cover to remove the pump shaft. Here's the end result.
Anyone see any problems with this idea?

[Ozhammer]

Provided there is a gasket between the blank and the case, I reckon that's about the most elegant solution I've ever seen Phil.

[gman]

Over engineered mate. But bling block of plate has to match the rest of your bike. I think you will find your main jetting with pod filters will need to be in the region of 380 to 410. Yes a huge increase over the stock 250. Rdrz forum has touched on this subject a bit. As far as the oil pump when ever someone is questioning it someone will vhime in and say send to Arrow. Yes he does great work but. I own 6 yamaha's 2t's running of the pump some a re 50 years old. From my experience if they have never runs dry them it should stull be good. As with anything mechanical there are specd that can test. I am without my notes but in testing the pump on my rz350. I disconnected the oul lines and counted 200 pump strokes at idle with pump manually held at max. 26cc's i think was bled from lines into shot glass then measured with syringe. Anyway thats what i do and it comes about from owning so many bikes that i test, measure, check over and ise if in spec. Not to say a pump rebuild wouldn't hurt.

Sent from my SM-G900I using Tapatalk

[phil1rowe4]

Cheers gman,

I did try collecting/measuring the oil output from the pump but not at maximum pumping level. I might give that a go.

The problem I found was that the RHS oil feed pipe (to carb) kept having air bubbles whereas the LHS oil feed pipe didn't. I thought I bled the oil pump properly. The LHS primed quickly and seemed to work fine but the RHS kept introducing air bubbles into the carb feed line. (Clear oil feed lines)

I might hook it up again and see if I'm priming it properly (and measure the output) before sending it off.

The block off plate probably is over engineered but it does allow me to remove the pump without the hassle of removing the oil pump shaft. It would have been bling if I'd polished it but it sits under the oil pump cover, so not seen.

[gman]

I was only having lol on the oil pump shaft cover over engineering and you right it does allow you to remove the pump withought the clutch cover removal. I did wonder if the shaft might float and get caught on the primary drive? Also is there much play on the shaft? If it could be pushed and pulled more then a few mm's the metal locating dowl could fall out into the clutch area? Although I don't think it would. As for the oil pump it is a single pump with 2 outlets. If it has been removed or run out of oil, air can enter the system. It is then best to remove the bleed screw to allow oil to flow from the tank until free from air bubbles. Then whilst the oil lines are disconnected you can rotate the pump pulley to simulate maximum flow whilst the engine is at idle on premix This will speed up the removal of and remaining air bubbles.. Don't quote me on the 26 cc's of oil at maximum stroke 200 pumps. I'll find my notes and confirm those numbers. I believe it has been dissussed on rdrz forum. I would try bleeding then attaching a small flask ( shot glass) on the end of each line then simulate pump at max with bike at idle and try to count 200 pumps of the pump and see how much you get from each line. Curious as to what main jets where in your carbs before they where rebuilt? (240 is stock)


Sent from my SM-G900I using Tapatalk

[gman]

My low tech block of plate. No pump shaft though.

Sent from my SM-G900I using Tapatalk

[gman]

Bleed screw under the screw driver head.

Sent from my SM-G900I using Tapatalk

[gman]

Ok like i said don't't quote me on the oil output. According to the manual it should be between 2.54 -2.85cc's per line with pump set at maximum for 200 strokes. Need a good syringe to measure. My thinking from what you first said about more smoke from left pipe reminded me of a similar symptom i had on my rz years ago. I thought that maybe the the left cylinder was sucking trans oil through the case joint becuase i was running premix so it couldn't be the pump. In the end the bike was also having trouble idling. It turned out that the pulot jet was blocked on the right cylinder and the bike was really only running on the left cylinder at idle. Maybe you had a similar problem as you mentioned pilot jets. Has the smoke evened out scince changing you pilots?? I really think with the pods you'll end up with a 30 pilot and 380+ main jet. Without the airbox there is a weak signal in the venturi to pull on the fuel from carb. Just my 2 cents from experience and what i have read.

Sent from my SM-G900I using Tapatalk

[phil1rowe4]

Thanks for the feedback gman,
I might be able to build stuff ok but its been a long time since I've tuned at 2T!

The smoke from one side (LHS) was from the pilot jet being blocked on the RHS so was only running off the LHS. All good now with the 25 pilots.

Regarding jetting, I was expecting to go up at least 2 sizes on the pilots (from 22.5 (Stock) to 27.5) but the plugs are still very wet with the 25 jets, so want to do some road tests to see how it goes before making it any richer. I appreciate about the weak signal by removing the airbox but I would have thought the plugs would be dryer if the bike was running too lean. Should the plugs be wet if just idling and low revs (3-4K) (I haven't the revved the motor past about 5K cause it's still very new!)

I'll have another go with the pump and measure the output after priming/bleeding it again.

[gman]

you would think the plugs would be dry if you where lean. One thing to consider is if you are using br9es plugs the engine will not get hot enough at idle to burn effieciently. Even br8es plugs would probable stay wet without hitting the road. The old tz guys would do a start / and warm up with 7's then drop the 9 or 10's in once at full operation temp then hit the track. Also if your timing is of you could have a similar symptom. In the past i have tuned some carbs by removing the main jet altogether so as to not have any leaning effect on the needle jet. once the needle was set for optimum mid throttle responce i then worked on the mains. Your air filters being oil'd could reduce your jet size closer to stock over dry filters. Anyway these are just some things to consider. Sounds like your on the right track. short road rides and keep an eye on the plugs. ps i am running y boot (2 into 1)with dry k@n filter on my rz250. it has 27.5 pilots. needle clip in the middle with 280 mains but then it has power jets that add about 60 to the mains aka 340. good luck phill.

[phil1rowe4]

Hi,

Been a bit distracted lately with an RGV250 that came up for sale at the right price. Hope to get it registered and ride around a bit before maybe changing to a lucky strike colour scheme. All major plugs are wire locked so it has likely seen some track time.

Also been working on the final paint scheme for the RZ hybrid and have settled on aupdated paint scheme.

[phil1rowe4]

Sidestand fabricated this weekend in between lots of sanding of the fairings.



Here's the planned paint scheme.

[Ozhammer]

I'd be distracted by a tidy RGV like that too Phil! Like the final paint design, which still identify it as being a Yamaha but still different enough to make it stand out.

Rgds
Mark