Topic: RZ350 Kenny Roberts

[grcamna2]

Got a new crank. New pistons one .010 over.  Old timer in town already bored and honed them for me.  waiting on some seals and bearings and I think I can start putting it back together.

Excellent. I think it's nice you found the top-end locally.

[harisuluv]

A bit overdue for an update.  I have to say I did a very poor job of taking pictures of my progress, but here's where I'm at now.  The engine is now totally rebuilt and installed.  I replaced the crankshaft, and pistons, one size up, got them bored locally.  Did a little painting, assembled everything, and she fired right up.

-Had a small exhaust leak at the can-fixed.
-Coolant leak at the thermostat (part on order)
-Need to hook up a couple things still (YPVS, couple electrical connections).

Only thing of concern is that I am getting some chatter out of what sounds like the right side cover.  Not really sure what it is, but possibly kickstand related.  I don't always get a smooth return to neutral position after kicking.  Pulling the clutch in doesn't seem to change the sound.  Might have to do a little exploratory surgery or try and pinpoint the sound.  I also don't know at all what "sounds" normal. 

Also pictured is the gas tank.  Really beautiful paint and no dents, but had some bad rust inside and big time leaks.  I sealed it with a caswell kit and now it's super solid and no leaks.  Anyways, here are some pictures.

[joeyvans]

Aside from the chatter, things are looking good! How did those Toomey's sound?

[harisuluv]

Aside from the chatter, things are looking good! How did those Toomey's sound?

Yes!  They sound like essence of two stroke.  I'll get a video sooner or later.

[grcamna2]

Nice  work

[GroovieGhoulie]

LOVE strokers!  Have an '86 NS400R and some dirtbikes and I can't get enough of it.

Describe the "chattering", if you can.  Is it a constant "ratcheting" that changes with rpm? 

Could it be the kickstart pawl isn't fully disengaging when you kick it, and when the engine fires, it's in there, ratcheting around?  Maybe the return spring or something is worn or off its lug, and it's not fully retracting the kicker gear when the kickstart is raised?  Had that happen on a CB360, (previous owner somehow broke it and bubba'd a "repair".  Required a new bottom case. 

This may also explain why the kicker won't fully retract?

I hate "weird" engine noises.

But overall, a badass machine and I'm glad to see you brought it back from the dead!  I do love those RZs!

[harisuluv]

LOVE strokers!  Have an '86 NS400R and some dirtbikes and I can't get enough of it.

Describe the "chattering", if you can.  Is it a constant "ratcheting" that changes with rpm? 

Could it be the kickstart pawl isn't fully disengaging when you kick it, and when the engine fires, it's in there, ratcheting around?  Maybe the return spring or something is worn or off its lug, and it's not fully retracting the kicker gear when the kickstart is raised?  Had that happen on a CB360, (previous owner somehow broke it and bubba'd a "repair".  Required a new bottom case. 

This may also explain why the kicker won't fully retract?

I hate "weird" engine noises.

But overall, a badass machine and I'm glad to see you brought it back from the dead!  I do love those RZs!

Yeah I think it is kickstart assy related, the kickstart gear is just barely touching and i think it is grazing perhaps when things are moving around in there.  There's a plastic bushing/spacer that had a bit of wear, besides that everything else looks pretty kosher. 

[harisuluv]

Update:  Fixed the weird noise coming from the right cover.  The kickstart assy, namely spring was not quite seated in the slot.  Must have come unseated while fiddling with trying to get the cover on.  Sounds very quiet now.

Now I need a new master cylinder.  The one I have is totally gone.  Can't even get it out, if I could get it out, the bore would probably be wasted.  Is it possible I can just swap another one?  Maybe a modern radial or something?  Very hard to find a used one on ebay.  A new one is $300.

Would really like to avoid Chinesium parts if I can!

[Stev-o]

Hey James.... I used this one on my RD350, works good.

https://www.mikesxs.net/product/08-6009.html

PS. PM'd you about the need for some 069 jets and needles, have any for sale?

[harisuluv]

Steve, that's a single, the RZ is a double disc up front.  Looks like he has a lot of different types.  Looks almost all chinesium.

069A needles are pretty rare to have in stock, don't have any at the moment, last ones I had I sent to a member.

[Stev-o]

Steve, that's a single, the RZ is a double disc up front.  Looks like he has a lot of different types.  Looks almost all chinesium.

069A needles are pretty rare to have in stock, don't have any at the moment, last ones I had I sent to a member.

I stay away from chinese parts as much as possible. Could not find a good OEM for the RD, so I went with that one. Mike's has a pretty good reputation with their parts and service.

I'm sure you can find a modern MC if you rather go that route?

[scottly]

Now I need a new master cylinder.  The one I have is totally gone.  Can't even get it out, if I could get it out, the bore would probably be wasted.

The grease-gun trick that works so well on caliper pistons works just as well on MC pistons. I did it a while ago on a stuck FT rear MC, and after cleaning up all the dried 20 year old brake fluid, I reassembled it with all the original parts and it works fine.

[harisuluv]

Update:

1)  The grease gun trick worked great on the master cylinder.
2)  Everything is all put back together but need new front brake parts still (to be delivered on wednesday 10/21)
3)  Had initially fixed the extensive holes in the bottom of the tank with a caswell kit.  Worked great and it held water, but 2 weeks later when I filled it with gas there was *one* pinhole I hit it again with a mini caswell 3 gal kit and crossed fingers.  No more leaks, tight as a drum.
4)  There was a terrible terrible noise when at higher speeds and I thought it was pistons about to seize or scraping, turns out it was the tach or speedo gear.  Oiled and now quiet.
5)  Spent today tuning.  This thing was someone's track bike or something but it didn't seem like it was tuned for it maybe.  I looked around to see how readily available stock airboxes are and found zero.  Sent some PMs to some people on the rz forum, will see if I get any luck there.  Bike is obviously running lean, bogging, would run way better with choke on.  The stock intake was replaced by a y-boot with one jumbo sized pod.  I took some inspiration from the DOHC guys running pods on their CV carbs, and used their fix of covering filter surface area with electrical tape.  I covered right about HALF of the filter.  Seems pretty spot on right now--I will assess it as I go and see if I need to adjust it. 

Little sucker is pretty fast.  FUN too.

[scottly]

Bike is obviously running lean, bogging, would run way better with choke on.  The stock intake was replaced by a y-boot with one jumbo sized pod.  I took some inspiration from the DOHC guys running pods on their CV carbs, and used their fix of covering filter surface area with electrical tape.  I covered right about HALF of the filter.  Seems pretty spot on right now--I will assess it as I go and see if I need to adjust it. 

Try increasing the main jet size by about 30%. Too lean on a two-stroke can damage the motor in a very short time.

[grcamna2]

Nice that you have it on the road 

[harisuluv]

Been riding it daily for a month or two now.  Funnest bike I have ever ridden.  Very interactive riding experience, it wants to go fast.  When the power valve opens you KNOW.  Toomey exhaust sounds amazing.

[joeyvans]

Yes!  They sound like essence of two stroke.  I'll get a video sooner or later.

It's later, James!  Where's that video??!!!    Also, what happened to your lower fairing?

So freakin' jealous of you guys with RZ's. 

Kyle

[harisuluv]

I had to do so much fiddling with the power valve (ended up being a bad controller) that I didn't put it back on.  I decided it looks better without so just left it off.

Yeah you're right I'll take a quick video.

The RZ is a recognizable and rare bike, but I don't get the same amount of people coming up to me at gas stations and parking lots as a CB, I think most people just think it's some generic 80's sport bike.  Every once in awhile I see someone look at the pipes and do a double take like:  "wait a minute.. two stroke... streetbike?"

[grcamna2]

Yes!  They sound like essence of two stroke.  I'll get a video sooner or later.

It's later, James!  Where's that video??!!!    Also, what happened to your lower fairing?

So freakin' jealous of you guys with RZ's. 

Kyle

I'd like to take it for a nice Ride on a back road Do you still have the stock pipes for it and possibly hook them up w/ the 'YPVS' ?
Those had great low-midrange transition w/ the stock airbox(and a K&N in the box)and the oem pipes,otherwise they were peaky.

[harisuluv]

No never had the stock pipes.  They came with some EPA mandated emissions stuff on them anyways.  Alas, I am experiencing an intermittent electrical gremlin and the bike might be sidelined for awhile.  Getting cold anyways

[scottly]

So did you have to increase the size of the main jet like I suggested, or was the power valve the problem?

[harisuluv]

The power valve was the problem, the main jet was already increased--from being in the carbs I knew that the pipes and jets were probably purchased as a kit available from Toomey.

[toytuff]

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