RZ/RD 350 & Misc. 2-Stroke Tech BBS

Technical Forums for Two-Stroke Nuts
It is currently Sat Oct 20, 2018 8:08 am

All times are UTC - 4 hours [ DST ]




Post new topic Reply to topic  [ 10 posts ] 
Author Message
PostPosted: Mon Jul 02, 2018 11:42 pm 
Offline
User avatar

Joined: Sat Oct 10, 2009 4:33 am
Posts: 9696
Location: Sydney
Well, of course you might be able to... But I totally know now that I shouldn’t...

A few (cough!) years back I rebuilt the oil pump for my F1 with some seals I got from the ill fated TwoStrokeShop. They didn’t come with a gasket as Steve couldn’t source that but it was a half decent kit and all I needed was a special ‘screwdriver’ for the 3.5(IIRC)mm special bolt and I was away.

I found some online info and TSS did some kind of guide, armed with those and the special screwdriver’s arrival from China, I got on with it. I can’t remember exactly how careful I was in what I did but as you know I’m no stranger to taking things apart and putting them back together. I didn’t consider what I did to be slapdash and as this was my first ‘inside the pump’ foray I felt that I took my time to get it right. I even remembered to clean out the NRVs and did some work in setting it up after. When fitted I ran the engine up a little bit, but as it is (still) not painted I didn’t ride it.

Now then, since I did that work a bloke called Arrow on the forums had begun to offer a service to refurbish oil pumps for Yamaha models. He does a bunch of the Yamaha pumps including the TZR/TDR and RD/RZ models and as anyone who’s had him work on their pump knows, he really knows his stuff. I was very lucky to be able to visit him last month and had a great afternoon talking pumps. I know we would get on from our email conversations over the years, and I’m pleased to say that I wasn’t wrong, he’s a totally good bloke who really knows our pumps and does wonderful work. He showed me round his workspace, his special tools and even his spares stash. He filled me in on how they work, how they can be adjusted also educated me some of the wear issues with these units and how they differ over the years and from other models. Refurbishing these pumps actually requires a lot of work, far more than you might expect. The main thing I worked out very quickly, Arrow is an Expert, with a capital E. Nuff said.

Ever since I knew I’d be in the UK I had arranged to have Arrow look over the pump I’d rebuilt and see how just how well I had done. I felt that my work might be indicative of what any of us might achieve at home and that Mr Pump would be able to give me his honest opinion about my efforts. You might think it’d feel a little daunting to expose myself in this way, but as you know I don’t mind admitting my mistakes in public and felt it might be educational, for you guys as well as myself. This is what he said in his message to me on taking it apart:

Hi Jon, I opened up the pump that you built. 

On the plus side;
- All screws nice and tight.
- Seals fitted correctly.
- Nozzles fully home, no gaps underneath them.

On the negative side;
- Gear fitted wrong way round, this puts a bit more strain on it due to the drive.
- Front plain thrust washer wrong way round, best to keep parts that have run together, together, witness marks etc.
- Both check valves passing heavily. Very fussy item that needs scrubbed seats and close inspection. Pump must be spotless through out to prevent re-contamination.
- No rework on shafts.
- No grease in front housing.


Eek... Well I knew he was being kind when he started off with a positive about the screws being tight LOL Obviously there are some serious issues here, backwards gears, passing valves and the lack of grease that should have been obvious really and luckily none of the silicone I used to stick the gasket back together had got in the pump that would have been catastrophic if id been heavy handed there of course and I know that worried him when I told him what I had to do with the gasket.

The good news is that the pump has now been fully refurbished by Arrow and as we’ve come to expect it looks amazing, better than an new OEM unit. Spending time to learn about the process means that I now know that beauty is much more than skin deep with Arrow’s work though and I can be confident about using this pump on my bike now, unlike I was (and rightly so) before.

As an aside I also had him work on a 250 pump I had. I picked it at random from a box of them that I had lying about as I’ve never rebuilt a 250 before so they just sit in their own filth in a box, poor things. When I collected it after the refurb I was shown that this very pump was a great example of just how worn some parts of these pumps can get. Here are two parts that should not have any wear... Just look at the steps!

Image

When we measured the screw shaft wear Arrow quickly worked out that the pump was actually providing a negative stroke! Scary and probably what killed that engine perhaps leading to why it ended up in my spares. There was even wear on the pulley from where the throttle had been pinned so many times, taking these wear elements together it was deduced that it was probably off a bike that had been raced. What was especially interesting was that the bore was perfect and internally it was in great condition, yet more testament that these pumps were designed and built well; 35 years of abuse and it was still working on a machine that the manufacture never expected to have anything like that many birthdays.

Looking back at what I’ve written I see that I haven’t included many photos here... It’s a crazy fact that there seems little point putting up yet another photo of an Arrow perfectly restored pump, literally hundreds of them have already been posted by happy customers and we’ve all seen them before on the forums and my own restorations include them too. We all know they look glorious, and are just like 'yeah yeah' lol. Ok... Perhaps this pic of 3 in a group might be a little different LOL

Image

So what have I learnt? Well... Pretty much I confirmed what I already knew that this work is best left to the professionals, especially now that we have a tame one in our midst. It cemented my view that that you cannot hope to replicate the work done by a Pro on a part so integral to the longevity of our expensive engines. Just a few minutes after meeting him, Arrow showed me his ability to look at parts and identify them as wrong for the pump in question and/or see what’s wrong with them even without measuring, he’s done that many of them now he just can tell at a glance. Spending time with him proved to me that we are very lucky to have him; his knowledge with these units is invaluable and that he has a waiting list for his services for a reason.

Often I see posts on the forums from people who want to do their own pump refurb and I (and others) always post to advise them to send it to Arrow. Sometimes they moan about the price, especially of shipping if living outside of the UK, but really this is a key component of our engines and the cost of a pro working on it is actually just cheap insurance, especially after all the big money some of us spend on cylinders and cranks. As the man himself told me, ‘The work I do on these pumps means they wont just work for another year or two, they will be good for another 30+ years’. After actually seeing what he does from start to finish, most of which you don’t see (refinishing, grease etc) or he doesn’t brag that he’s done (small mods for longevity, swapping parts for better ones in his spares and detail refinishing of edges and lapping surfaces etc), I’m not surprised by that. In conclusion, I think we are very lucky to have him, I know that I don’t want to go back to making a mess of my own pumps, I doubt you do either.

_________________
My Projects:
Yamaha '85 RZ350 F1 & '83 RZ & RD Athena 421 LC & XT500 Supermoto & Honda MT250... See them all on www.2smoked.com

Like Watches? You will love www.PloProf.com & www.DeskDivers.com


Last edited by JonW on Tue Jul 03, 2018 1:44 am, edited 1 time in total.

Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 12:11 am 
Offline
User avatar

Joined: Fri Nov 01, 2013 8:34 pm
Posts: 1322
Location: back in the hills
Contact info?

_________________
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
Salvador Dali


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 1:22 am 
Offline
User avatar

Joined: Sat Oct 10, 2009 4:33 am
Posts: 9696
Location: Sydney
His username is Arrow on the forum, drop him a PM, he usually replies within a day or so. hth Trex.

_________________
My Projects:
Yamaha '85 RZ350 F1 & '83 RZ & RD Athena 421 LC & XT500 Supermoto & Honda MT250... See them all on www.2smoked.com

Like Watches? You will love www.PloProf.com & www.DeskDivers.com


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 3:29 am 
Offline

Joined: Mon Sep 02, 2013 6:47 am
Posts: 223
Jon mate, thank you for that really special write up. Its very much appreciated.

The restoration service actually started by total accident, just helping out a mate after I had a problem with my own 250E pump back in 2009. He told someone else that I could help him also and that guy posted on a forum that I was offering a service! At that time I certainly wasn't!

The pumps started arriving and the work changed quickly getting more involved and refined. I was starting to see a lot of the pumps from as early as 1967 to around the mid 90's. I saw faults in the design that could easily be corrected. Seeing the later pumps confirmed my thoughts, because Yamaha made corrections too. Some were not necessary and caused other issues, but that can also be put right.

After studying the pumps in great detail and seeing the popularity of the big bore kits, I set about developing the uprated version. I got a willing volunteer to test the prototype a good few years ago now. I guy sent me an email asking if I could modify a 125 pump to suit a 180cc kit. That's a big increase I told him, let me think about it. I got back to him. I had thought this through about twelve months before and didn't write anything down! Silly me. That modification is totally different to the twin outlet pumps, but as we all know, most things are possible these days, given some thinking outside the box.

Sometimes it's hard. Sorting issues like the wrong pump on the bike, then trying to find the (harder to get these days) correct parts. And with so many different pumps and setups I need to have seven different types of advice notes, sent after the job is complete.

All good fun,
Arrow.

Sent from my SM-A520F using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 3:44 am 
Offline
User avatar

Joined: Sat Oct 10, 2009 4:33 am
Posts: 9696
Location: Sydney
No problem at all mate, I really enjoyed hanging out with you and learning more about these pumps, there is a lot going on in there for such a simple device.

_________________
My Projects:
Yamaha '85 RZ350 F1 & '83 RZ & RD Athena 421 LC & XT500 Supermoto & Honda MT250... See them all on www.2smoked.com

Like Watches? You will love www.PloProf.com & www.DeskDivers.com


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 6:12 am 
Offline
-----
-----

Joined: Fri Oct 03, 2003 11:11 pm
Posts: 3464
Location: Southern Ontario, Canada
An important consideration on these is setup, the internal pump cam and the pin that runs on it will wear over time, which reduces the pump stroke across the range. This might not matter with the throttle open but it can eliminate your idle flow. if you have zero clearance between the end washer and the cable pulley with the pump plunger at full stroke (all the way out) and throttle closed you are not getting any oil at idle even if the pump is flowing within spec at full throttle. Also notable is that no amount of shims or cable adjustment will increase the pumps maximum output, it will only get you to it sooner.
If you aren't adept at working with small fiddly things and can't (likely) find all the correct OEM parts, heed Jon's advice.


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 8:40 am 
Offline

Joined: Mon Sep 02, 2013 6:47 am
Posts: 223
RuZty wrote:
An important consideration on these is setup, the internal pump cam and the pin that runs on it will wear over time, which reduces the pump stroke across the range. This might not matter with the throttle open but it can eliminate your idle flow. if you have zero clearance between the end washer and the cable pulley with the pump plunger at full stroke (all the way out) and throttle closed you are not getting any oil at idle even if the pump is flowing within spec at full throttle. Also notable is that no amount of shims or cable adjustment will increase the pumps maximum output, it will only get you to it sooner.
If you aren't adept at working with small fiddly things and can't (likely) find all the correct OEM parts, heed Jon's advice.
That's pretty much 100% correct Sir, but please allow me to clear up just one thing.
The shims/minimum stroke have an influence right through the rev range.
If the minimum stroke is zero the maximum stroke (for an RZ) would be 2mm, which is out of spec. With a shim gap of 0.25mm the max stroke will become 2.2mm, thats in spec. With a negative minimum stroke the pump will not achieve 2mm, even at full bore.

Sent from my SM-A520F using Tapatalk


Top
 Profile  
Reply with quote  
PostPosted: Tue Jul 03, 2018 10:23 pm 
Offline
-----
-----

Joined: Fri Oct 03, 2003 11:11 pm
Posts: 3464
Location: Southern Ontario, Canada
Good point, I had not looked carefully enough at the full throttle case and did not realise that the pulley still limits stroke when fully open. On my particular pump I would need a shim of at least 0.5 for the plunger pin to reach the bottom of the cam lobe to provide maximum stroke.


Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 04, 2018 12:42 am 
Offline
Moderator
User avatar

Joined: Fri Dec 11, 2009 9:56 pm
Posts: 992
Location: Niagara Ontario Canada
:smt038

Thanks Jon for taking the time to write up your story.
And thanks Arrow for your continued efforts.

_________________
Colin
79 RD400F Daytona Special
81 RD350LC
89 TDR250
75 Kawasaki H1 500
77 Can-am Tnt250


Top
 Profile  
Reply with quote  
PostPosted: Thu Aug 09, 2018 3:23 am 
Offline

Joined: Mon Aug 20, 2012 1:37 am
Posts: 1809
Location: Calgary, Alberta
I both love and hate Arrow. The service he provides is not cheap at all but it is damn good service and in comparison to the cost of a complete motor rebuild due to a pump failure, cheap in the long run. My biggest issue is I have 5 motors and had pumps done for all of them. Hated paying that bill. :(

_________________
'81 RD350LC hybrid project bike - in pieces currently
'82 RD350LC in '81 colours - Built by "Solo 2" OEM pipes, UNI filters
'90 RZ350F2 with 31K motor, OEM F2 pipes & airbox


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 4 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 8 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group