Messages

1

Tech Talk / Re: NGK B10E & B10ES

« on: April 01, 2024, 10:25:26 PM »

On old charts S is for standard 2.6mm electrode. most electrodes are 2.5. Later charts as mentioned by Sleepy show it to be copper core 2.5mm electrode. Your item could be either depending on its age so measuring will tell you.


As you guys all know running a modern plug designed for modern systems with hi energy and maps on an old system is the same as running 98 fuel in a low comp engine. It just cant make use of the modern design as subtle as they are. Im no electrical engineer to be able to work out what my systems need just by the codes further than the basic size reach and range so i like you guys rely on the suck it and see. if it works it works and i cant see a reason to change.

2

Suzuki / Re: RL250 forks - are they 35mm or 1.3/8inch ?

« on: January 19, 2024, 10:42:16 PM »

I wonder what tube size they started with, any machining and what thickness of hardchroming was used.

Logic tells me they started with 35mm tube before grinding and "hoped" the chrome bought it pack to spec though an extra 5mins in the bath is worth millions after a month of production. Remember this was early/ mid 70s and Japanese marques were having a huge rush in production and parts common to many models likely received Nominal components that existed only on paper and not on the blueprints.

As for your issue perhaps throw the legs on a lathe and or install a bush or, if like me you dont have  the space for a lathe id try a few seconds with a hone as i figure thats what the factory would have done on the floor. Just ensure the the ring and seal stopper slide over  the new stanchions.

3

Suzuki / Re: RL250 forks - are they 35mm or 1.3/8inch ?

« on: January 18, 2024, 09:14:04 PM »

Supposed to be 35mm and I doubt any imperial was used on the RL. Possibly that thing they called tolerance or mass production. The actual size used on Suzuki forks is usually a tad under what is specified. My Suzuki's have NOS units and measure 29.96 and 29.97 for a 30mm specified. perhaps your other stanchions arnt suzuki.

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General Discussion / Re: Any old boys still here ?

« on: November 25, 2023, 10:26:54 PM »

Going via the Internet Archive Wayback machine you can see some topics dated from sept 12 2005. I think i found the site not long after.

5

Tech Talk / Re: CR250M inlet port height different, why?

« on: September 10, 2023, 09:59:43 PM »

There was an old mag article that said it was for angles , this was also the time when crank stuffing was promoted. Ask yourself, if it was angles then why didnt all use it the next year and Honda would have kept doing it and none of that happened, perhaps Honda did it just to confuse everyone else.
 Often the simplest answer proves to be the best and such is the case with this "adjustment" for the ring gap and still allow relevant charge amount to be induced within the relevant allocated time.

Plenty of very experienced people have tried even more different methods of improving a 2T engine by modifying the bottom end and they all came to the same conclusion. SFA benefit from anything and nothing that a good pipe couldn't overcome by scavenging. Not corking the flywheels or installing a turbo crank or changing volume as the pipe does the best job of scavenging unless you are using forced induction like snow mobiles and thats a whole new story.

Angles , volume and velocity are all nullified once the transfers are in charge. The inlet is just a method to get the charge into the engine and the bottom end is convenient for it and could even be remote like the first patent on the 2T engine. The bottom end doesn't care about where the charge came from as its a glorified metal tank with an inlet and outlet valve(piston/reed/disk).  Its the transfers the head the pipe and the ignition that give performance, with the CRs its mostly the pipe that did a decent job of scavenging with a decent head design and a well matched gearbox..

6

General Discussion / Re: Anyone know US buyers that can post parts to Australia?

« on: August 30, 2023, 02:25:57 PM »

Are more than a few places that do free US addresses.
https://www.google.com/search?q=us+mailing+address+for+online+shopping&rlz=1C1ONGR_enAU1039AU1039&oq=us+mailing+address&gs_lcrp=EgZjaHJvbWUqBwgBEAAYgAQyBggAEEUYOTIHCAEQABiABDIHCAIQABiABDIHCAMQABiABDIHCAQQABiABDIHCAUQABiABDIHCAYQABiABDIHCAcQABiABDIHCAgQABiABDIHCAkQABiABNIBCTEwODcyajFqN6gCALACAA&sourceid=chrome&ie=UTF-8

7

Tech Talk / Re: Tail light issue on 06 KTM 250 exc

« on: August 13, 2023, 01:12:27 PM »

Typical Poor earth situation. either poor grounding or sufficient wire gauge as its only good enough for the one circuit to operate at a time. First check your grounding so its good.

8

System problems? / Re: Is security certificate going to be updated?

« on: August 10, 2023, 09:25:18 PM »

I believe you have hit it on the head Peter.  Its an issue with an over zealous security program on the users device  marking the page as a possible threat for some minor issue with the page or the host. Lowering your security settings or marking the page as safe should see the issue resolved.

I run low settings on windows preferring to make an educated choice rather than allow a glorified spell checker to make choices for me. I dont run an AV at all for much the same reason as annoying false positives but I do have malware programs set to scan  quarantine and ask for instruction once a week. And before someone says its risky i am microsoft certified in various platforms.

9

System problems? / Re: Is security certificate going to be updated?

« on: August 09, 2023, 10:23:39 PM »

Works fine with chrome  so looks like its a local issue with your PC.

10

Tech Talk / Re: RM125S Piston rings without notch for pin, eh?!

« on: July 17, 2023, 07:23:51 PM »

This service bulletin for 1975 I think you may find handy. http://www.ozebook.com/compendium/techbuls/SerBulletin%20Specifications%201-5.pdf

11

General Discussion / Re: Ideas for carb jet holder?

« on: April 25, 2023, 12:02:17 AM »

Indeed John, its all that works for you. i have a small plastic box for the mikuni jets with strips of grey stiff foam with holes curtosy of a rotary leather piers and the foam is still holding up after30years.   I have replaced one row  in that time from being a bit loose Im sure there are neater systems but this works for me.  I still have to look for the numbers but after 30 years it still a work in progress,  Ive seen the Mikuni setup and its nice though I cant say it works better than mine,

12

General Discussion / Re: Ideas for carb jet holder?

« on: April 24, 2023, 04:30:21 PM »

I seen this stuff the other day and looked handy for something. Sorry didnt measure the holes but it may get your creative mid working.
Bunnings $25
Sheet is 91cm x 91cm

13

Tech Talk / Re: My TS125B jetting specs, eh?

« on: April 12, 2023, 10:30:12 PM »

 Seems the only thing your missing is a decent pipe  to start surprising more exotic bikes. 
Blair and Frits Overmars both have good theory to base a pipe on that will out perform any of the old after market or stock chambers and a good place to start.
 You can download a demo software that works for calculations free or you can buy it. ( Direct link so save as and run as admin) 
http://ypvsbox.free.fr/software/PipeDesignerDemoEngSetup.exe
 And you can use either Blair or Overmars calculations.

14

Tech Talk / Re: My TS125B jetting specs, eh?

« on: April 12, 2023, 06:13:34 PM »

I was thinking that "faster air" creates a greater drop in venturi pressure, causing more fuel to flow from the jet?

Correct John,  with  greater available lift comes more potential volume. It also effects droplet size for better atomisation. (this is why sometimes a smaller carb is better as the air is faster)The key is keeping the charge volume up while keeping the velocity up and thats where the pipes harmonics starts doing it thing so its a matched set and maximising the engines efficiency.

Other things the bike will enjoy is dropping a fair bit of weight off the flywheel as its a heavy sucker and it honestly doesnt need it all. The original was designed that weight to smooth acceleration on road and have a bit of roll on in super tight stuff and i dont think you will be doing much of that.

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Tech Talk / Re: My TS125B jetting specs, eh?

« on: April 12, 2023, 03:26:13 PM »

Its the pipe, its for a 125

Its not only the amount of air the engine can pump its the velocity of that air in and out. With faster air you can run larger jets for often better performance and that can come from going to a smaller carb. Then you have the pipe that also dictates how much air that engine needs. If you had a size smaller carb  like a VM29 from an ER it may be what you need for that pipe ,Worth a try if you can lay your hands on an ER carb.  Your on the right track though perhaps over carbed" for now" and underpiped for optimum efficiency.  Overall id stick with the 32 carb (I run one on my very modified 199cc PP engine) and build a pipe that suits the engine as thats where its choking and it cant use any more fuel.
Best of luck with it.