I have an air cooled climber motor, but found the gearing very high, even with 10t gear box sprocket, and 54 tooth rear. Eventually I will change the crankshaft pinion and clutch basket for earlier ones.  Have fun !

2 day trial at D'All is very good I'm told, are you riding this year. 

Welcome, you havn't kept the climber clutch casing ?

I was going to suggest j b  weld, trouble is if its not successful if make welding more difficult. 

3 minutes ago, Mal8504925 said:

Hi b40rt thanks for the reply. I’m in Fife (Scotland) my only concern was the available space to fit a weld repair and the chance of shattering what is there with heat stress. 

@breagh Alan can you recommend anyone ?  I'm sure the plate would be ok being welded. 

 

A competent welder should be able to repair that easily, there's no real stress on it so doesn't have to be super strong. Possible cause being the stator was loose for some time. Where are you so people can recommend a welder. 

I thought I read somewhere they modified the clutch to reduce engine braking ?

1 hour ago, faussy said:

Did they give you legitimate reasons for runner those ratios? Most don't! 

Apparently these ratios are only ok if you mix fuel in 6L containers ?

13 hours ago, pschrauber said:

Scandinavian rigid I would guess?

Look like "leaf" springs to me ...

44 minutes ago, konrad said:

Not sure I understand your question.  The key size is based on the diameter. The tightening torque is a function of several parameters (e.g., grade, diameter, pitch) but length really does not enter into it.  Are you looking for a specific bolt?

 

Yes, m8 for bottom shock mounts on twin shocks. No real stress on these, button tops don't tend to get snagged on passing scenery ?

Excellent work, (thought you had been abducted !) exhaust as shown might lack bottom end power ?

3 hours ago, konrad said:

My mistake, I'll blame my poor English skills.

In the US, McMaster-Carr  https://www.mcmaster.com/standard-rounded-head-screws has been a great reference source for as long as I can remember.

They say "fully threaded" or "partially threaded" (which is far less common).

Appreciate your input, I've yet to find any "partial threaded" I'm assuming its because the relatively small allen key size isn't sufficient for proportionate torque ?

3 hours ago, trialsrfun said:

FWB Products @ Stoke on Trent https://www.fwb.co.uk/ or Barfast http://home.btconnect.com/barfast/ these people also stock metric fine, I highly recommend Britannia Fasteners Burslem though they do not have a website.

Thanks triailrfun, I'll try both. 

3 hours ago, konrad said:

They're very common in the US, often called "button-head cap screw" or "socket button head".

Thanks konrad, common here to if you want set screws, but not as bolts. 

Minor hijack, any one found a source for Allan button top bolts ?

Don't think it will be the coil, they tend to work or not work. But worth eliminating if you can borrow one. 

 

 

Sounds electrical, failing ignitions start to break down as temperature rises. 

@Andy

3 hours ago, midlife said:

Years ago I raced Mx and had YZF 400 Yamaha .If it sat for a week I was difficult to start but if I drained the fuel and put fresh fuel in started no probs.

Someone told me about the fuel loosing its kick in a plastic can so i put an alloy tank on the bike solved all the problems.

I thought you ran everything on red diesel ??

12 minutes ago, breagh said:

So we've went backwards. never used to have any bother ,pistons , barrels ran for ever and always seemed to run fine.

Now if you keep a bike a while they fill up with gunge carbs seem to go out of tune all the time there's always oil lying about motors even if you run them lean.

I don't believe any modern oils are made with slow running cold 2t engines in mind and if they have they've not been tested in my back yard.

Modern oil is probably better in old air cooled motors, at least they get hot !

Speaking to a friend who's an excellent mechanic, his only comment was not to use fully synthetic engine oil in NEW engines until the rings have a chance to bed in. Excessive oil consumption due to bore becoming glazed was a problem with Vauxhall's for a time. 

8 minutes ago, faussy said:

You're the one who doubted a guys legitimacy in riding trials just because you didn't know 6 litre petrol cans existed! If that already went over your head, I have a feeling adding more would also

I doubted his legitimacy because he obviously can't back his statement with any facts. Quoting 2 stroke ratios for 6 litre containers, seems as pointless as your comments !

20 minutes ago, old trials fanatic said:

FWIW i was told by the Motul rep ages ago that full synthetic in a trials bike doesnt burn away in the silencer because the motor doesnt get hot enough like a moto crosser or race bike so they recommended semi synthetic. Actually they recommended their "scooter oil". I've used semi synthetic ever since with no problem but i am sure many will disagree. Always a horny subject this with so many different "recommendations". As long as the user is happy then thats as good a result as you can hope for. 

Thanks otf, so depending where you compete will make a difference, 4 times round a field, or more traditional trials with long climbs that get some heat into the engine. 

5 minutes ago, stpauls said:

Anyone confirm this?

Plastic tanks definitely are semi porous, so I can see there being some validity to this. Ambient conditions will obviously be a factor.

3 minutes ago, 2stroke4stroke said:

Silkolene recommended I use semisynthetic in air cooled 70's motor when I asked their advice.  Various ratios suggested according to terrain/use but 50:1 for what we do.  Works fine with no sign of excessive smoke.

Why only semisynthetic ?

 

1 hour ago, faussy said:

Whats price got to do with? They are made by numerous manufacturers and are a far superior can. You obviously have never used one seeing that you didn't even know they existed. They are rather common with the gardening and landscaping fraternity. Just because it doesn't make sense to you doesn't mean it doesn't make sense.

Have you anything relevant to the topic to add ?  ( I think your last line should read "just because it doesn't make sense, it doesn't make sense )