Repair-Chat
This page is for any comments, pictures, stories or information you might want to impart to the site that don't necessarily
fit anywhere else on the website.
There are rules!
Primarily don't be rude, offensive or obnoxious, for more details CLICK HERE
See Older Posts
Ren - The Ed¹ said :-
I have no issues with the visuals of any 2 strokes as they look like, well, motorcycles. My problem lies is the vague hit and miss nature of the air-fuel mixture and exhaust gasses passage through the system. At least in a marine diesel 2 stroke engine the flows are properly managed, with a motorcycle 2 stroke it's more like "some of the gasses will do what they're supposed to do". Plus the lack of proper lubrication - again not a problem with marine 2 strokers.
Oh, and the noise!
31/01/2025 07:52:28 UTC
Glyn said :-
Marine diesel two strokes, now that’s an interesting/boring subject depending on who you are. Does the Yamaha reverse cylinder 2 stroke engine cure any of those flow issues that you mention Ed?
31/01/2025 12:28:57 UTC
Ren - The Ed¹ said :-
Glyn - NO!
Marine 2 stroke diesels as fitted in some large ships have
a) A very large turbo or supercharger. This keeps a positive pressure around the base of the cylinder where the inlet ports are - ensuring that the fresh air charge (no fuel, that is directly injected) comes into the cylinder and not returning exhaust gases.
b) The inlet ports are around the base of the cylinder - separate from the crankcase and underside of the piston allowing proper pressurised lubrication of the crank and small ends
c) An actual exhaust port much like a 4 stroke.
d) Direct injection rather than mixing fuel with air, lobbing it into the crankcase and seeing if any of it reaches the combustion chamber.
Now I seem to recall that someone like KTM did a direct injection motorcycle 2 stroke. Better, but not much. If that could be combined with a forced air intake like a blower then better... but ram-air pressures are at best just a marketing feature.
31/01/2025 15:04:33 UTC
Ian Soady¹ said :-
You might think your welding is bad. Here's my attempt. In its favour it is at least strong.
31/01/2025 15:57:35 UTC
Upt'North ¹ said :-
I do. But,
I think you get through more grinding discs than I.
31/01/2025 22:59:18 UTC
KiwiJeff said :-
Just read a review of the latest Triumph Scrambler 400X, seems like a nice bike for dirty muddy gravel road work, however what is it with the "Upside down Big Piston forks? I'm aware it's something to do with less unsprung weight? But why put the fork slider tube down where all the dirt is! Having two bikes with "right way up" forks and both of these have rusty bits on the forks, the Inazuma because the chrome layer is too thin and the Bandit because its a bit old and used to live in a damp shed with the previous owner I can see that a properly used 400X is going to keep the Triumph dealers in business with fork repairs! I can get Inazuma fork tubes from China for £50 so not too worried about sorting the Inazuma. Most Inazumas in NZ suffer from fork rot to varying degrees but they are 6 to 11 years old now. I presume with your salted roads the problem would be worse there? I presume the 400X is just fashion over function?!
31/01/2025 23:02:00 UTC
Ian Soady¹ said :-
The short answer is fashion. Like some sports bikes now have aerofoils / spoilers on the fairings. Totally pointless.
01/02/2025 10:28:23 UTC
Glyn said :-
I saw the 400x recently in a German dealers showroom. The bike looks great and at a very reasonable price too. Then I looked a little closer and was sorry to see a single cylinder although the engine actually looks like an early Triumph twin. The same old problem for me was the high seat. The salesman said it had put a lot of potential buyers off.
03/02/2025 12:12:52 UTC
Ian Soady¹ said :-
High seats - another fashion "statement". I fail to see why we need such a huge gap between the back wheel and the mudguard to cope with - on a road bike - 6" or so of travel. It just makes those of us who are less flexible walk straight past what otherwise may be decent bikes. Although I'm not and have never been in the market for a new machine.
And what's wrong with singles?
03/02/2025 16:01:55 UTC
Glyn said :-
Out getting some steps in today and saw this in a ditch. I’m sure it’s a Honda of some sort but there was no decals or badges in sight. I don’t think I need this one although I was seriously tempted to find the owner for at least 5 minutes.
11/02/2025 19:43:53 UTC
Ren - The Ed¹ said :-
That, my friend, is a Honda CMX250 Rebel (or possibly the 125 version).
233cc (or 124) parallel twin with a 360 degree crank (pistons go up and down together, even firing sequence, bad balance). Based on the CD200 Benly motor which is a very strong motor. Single carburettor with a manifold. AND AND AND it's a 4 - FOUR stroke.
It is a WONDERFUL machine. After my little crash I couldn't bend my knee much so this was my first bike after the smash. I loved it dearly and would have another in a heartbeat... if I had the room.
12/02/2025 09:32:29 UTC
Ren - The Ed¹ said :-
Looking at the image again I might be seeing the remnants of an "L" plate behind the front mudguard? If so it will obviously be the 125 version.
12/02/2025 09:34:37 UTC
Glyn said :-
You are reliably correct again Ed. After a little more research I find that it is a 125cc registered with a P prefix on the number plate that makes it 1997 ish. It’s a little along the style lines of the Yamaha 125 Dragstar which was probably the competition at the time.
12/02/2025 13:20:57 UTC
Glyn said :-
So nice to know that there’s still guys in sheds being clever. Even more impressive that they’re moving with technology and machining up pieces like these (unobtainable) handlebar spacers for the TZR. A lathe would be welcome in my shed but a CAD machine well I can’t even imagine.
16/02/2025 10:50:11 UTC
Ian Soady¹ said :-
I have a small (3.5") far eastern lathe in my shed that I bought second hand for around £250. It replaced an antique Granville - probably pre (second world) war machine that was OK for the odd spacer but no good for anything like precision. The one I have now is surprisingly accurate and precise and is let down by my lack of skill rather than its own inadequacies. The pic shows spacers I turned up for the Electra's centre stand out of a fiver's worth of mild steel. I could buy the top hat ones for about £8 each but the central one is unobtainable. Plus I could make them to the dimensions on my bike rather than some theoretical "correct" one.
If you weren't too bothered about original look you might be able to knock something like your spacers up on a simple lathe. It often pays to think about alternatives for this sort of thing - for example with your spacers I suspect the extended part locates the bars so they don't rotate. They probably don't actually need to be integral to the spacers....
I'd love a miller but have no space and to be truthful probably couldn't either use it effectively or justify its cost.
16/02/2025 12:54:53 UTC
Ren - The Ed¹ said :-
Looking good that Ian - can we contact you if we need something machining up then? And what did you use to paint the stand? I've had "sturdy and long lasting" finishes with Hammerite but not necessarily "good looking" finishes. It's probably due to my lack of care and attention to detail though.
18/02/2025 14:10:48 UTC
Glyn said :-
Nice job Ian. The spacers are, as per your comment, used to align the clip on bars. The pin locates in the handlebar on the top and the top yoke underneath. My latest job involves stripping and painting the tank. The finish is actually very good but there’s various rust tracking under the paint. It’s easier to see in the white than the red.
18/02/2025 15:21:03 UTC
Ian Soady¹ said :-
Thanks both. I'm afraid I'm fully occupied making my own bits so am not really up to doing stuff for other people - but I would encourage them to buy a cheap lathe and have a go. Like this.....
https://www.ebay.co.uk/itm/176854329305...
19/02/2025 10:10:18 UTC
Ian Soady¹ said :-
Oh, the paint is Paragon black enamel. Even though it's from a years-old tin it still goes on well - if a lttle thick - and gives a good durable gloss.
https://www.stationaryengineparts.com/Paragon-Paint-Products/...
19/02/2025 16:57:30 UTC
Ren - The Ed¹ said :-
Cheers Ian. I'd never really thought about the kind of paints used on what I might term as "old" machinery. There's an amazing amount of stuff available which I wouldn't know about if it weren't for the tinterweb.
21/02/2025 08:50:11 UTC
Name
Comment
Add a RELEVANT link (not required)
Upload an image (not required) -
Uploading...