trapezeartist

Out! More air? Leaner?

Best to tell us where "local" is then.....

What did you do to get rid of the "dreaded backfire"?

Do you mean you couldn't shift the pipe, or couldn't shift the springs? To help remove the springs you can by a T-handle with a hook on the end. It's much better (and ultimately less painful) than struggling with a screwdriver or other bodge-tool. If the problem is removing the pipe, I'd suggest remove the springs and remove the silencer. Then the only thing holding the pipe to the cylinder head is the stiction, baked mud, exhaust sealant, or whatever. A good wiggling and thumping should get it clear.

Pad knock-off?

Does anyone have a contact number or e-mail for Golden Valley? There's nothing on their website and the contact page doesn't work.

I am on 127.5. I couldn't read the marking on the old jet, but the new one is definitely 127.5.

The jet did arrive in the post on Saturday (thanks, Allens Performance) so I went out for a practice today (Sunday). As far as I can tell, everything is exactly to Beta recommendations (120 main jet, 27.5 slow jet, needle in position 3, 2 turns on air screw, no idea about the spacer because I don't know what it is). I had also fitted an Amal slow throttle since last time. The slow throttle was definitely a help, though I still find the power comes in very sharply when going from closed to just-a-tiny-bit. The idle speed is set very low so I'll try upping that a bit next time. I still have the popping on the overrun. I'm not sure that it's a problem but it would be nice if it didn't do it.

Your "phut phut" is probably my "popping". I've just had the carb in bits to make sure it was all to Beta recommendations, but it has made no difference. Perhaps it's a "feature" and not a "problem".

I don't think carb cleaner would have done much as the blockage was rock-hard. The attack with a drill was the final attempt before throwing it away so there was nothing left to lose. As it is, I now have to throw it away: the drill did nothing to the object causing the blockage but did start spitting out brass swarf. I tried eBay but couldn't find what I needed. Lampkins put me on to Allens Performance though so the part is now on order. They had 99 in stock! Interesting reading. For a wobbler who hardly cracks the throttle off idle, it clearly shows the bits I need to concentrate on, and the bits I hardly need to worry about. I'm hoping the jet might turn up in the post tomorrow, in which case I should get a run out on Sunday to test it all. I'm not holding my breath though.

I decided to remove and check the carb on my new-to-me Evo 300 4T. I wasn't totally happy with the way it ran on my first practice day so I went diving in to see if I could find anything wrong. Just understanding the thing is the main problem. I've got the table of settings and the factory parts list, but I'm struggling to understand which part is which in a few cases. First off, the tables gives the start jet as a 60 and the slow jet as 17.5 or 27.5. However the parts list calls the jets that are 17.5 - 30.0 the starter jet! I'm hoping that's a mis-translationas the Italian version calls it a getto minimo (as opposed to the main jet which is getto massimo). Anyway, the photo shows my carb viewed from underneath. The jet on the right appears to be the main jet. With a touch of optimism I think I can read it as 120, so that would be standard. I think the one to the left of it is the start jet (as described in the table) and I think it is a 60. Am I right so far? Between and above those two is a third jet so I assume that is the slow jet (according to the table). I can't make out any number on it but it has a small emulsion tube built in to it, which looks a bit like the starter jet (getto minimo) in the parts list. When I took it out and looked through it, the light at the end of the tunnel was not circular so I surmised that it was partially blocked. Blowing through wouldn't clear it so I tried poking it with a fine piece of copper wire. Instead of moving the dirt I appear to have jammed it in and now there is no light getting through at all. Eventually I gave up with the copper wire and decided to get brutal with a small drill bit. I twiddled it by hand from both ends. I can feel the obstruction but I can't clear it. Am I right in identifying this jet? And am I right that I should be able to see clear through it? If so, it seems like I'll have to get a new one. Finally, just to make sure I'm not doing something else wrong: is that screw on the far left the air screw (that should be 2 turns out from closed)? Thanks for your patience, and please be gentle with me.

As I understand it, there is no licence required to do AMCA trials, in which case licencing shouldn't be a problem. I imagine you will have to give it a try to find out if your vision impairment is a real problem or not. I could imagine you having to move your head around more than other people would, and perhaps you will end up with your head turned slightly to the right so that you do have some vision to the right of centre-line (at the expense of the extreme end of your leftward peripheral vision). You may find that having a "minder" with you would help. In some ways I think you might have to be more careful in using a practice area than when competing on an event. In a trial you know that you have the section to yourself. But in a practice area you have no idea whether someone else might suddenly pop out of the trees on your right. I really hope this works out for you. On the face of it, I think you have hit on the best chance you've got of continuing on two wheels. Good luck!

Girls! Please. This is so unbecoming!

Looks good. Be sure to report back to us when you get home.

Yes, that's off as well.

I'm finding this thread very useful. I just bought a 2012 300 4T. At the moment I have no idea what is inside the carb, except the dealer I bought it from said they changed the needle height and the idle in the workshop before delivery. My first task is to get the carb off . So far I've successfully removed the airbox and the CDI unit, and loosened the jubilee clip holding the carb to the manifold. Next it looks like I'll have to remove the rear shock to allow the carb to come out backwards. What a pain! First I'm waiting on delivery of a stand so I can take the weight off the rear wheel. Given my raw novice status and the punchy performance of the engine, my main aim will be to try to get the engine to be a little more gentle and progressive at the bottom end. Any thoughts? I'd also like to get rid of all the popping on the overrun, which this thread seems to suggest is due to a lean slow jet and/or lean setting on the needle.

Looks like they're all around 50 miles or so from Bilbao. It all depends on your dates. It would definitely be fun to go and see how they do it in the Pais Vasco.

I just did a quick google and found the Basque Motorcycle Federation (http://www.fvm.es/). It looks like there are a couple of trials in September and a couple in October. I imagine these are "Open to Centre" events and there may be other club trials if you dig further.

I haven't been able to find the gear ratios of my bike online. The nearest I got was the info for a 2009 2T. The difference between first and second is a little over 20%. The difference between 11/42 and 9/42 is 19%.

9/42? That's even shorter than mine! I would think that would make second gear similar to first on standard gearing. Throughout my first day of riding I didn't use first at all. It would have had me on my a*** in no time.

I had my first ride today on my newly-acquired 300 4 stroke. Despite being told that the four stroke is nice and docile, it seemed pretty lively to me. The bike even offered me the opportunity to inspect the ground at close quarters on a couple of occasions. So now I need to calm it down a bit, as well as tune myself up considerably. A slow throttle will be the first thing, but I'm wondering about gearing. The standard gearing according to the manual is 11/42. When I spoke to someone at Lampkins, he suggested 10/42 for a novice. This puzzles me slightly as that is 10% shorter, so while speed at any given revs will be 10% slower (reducing the need to slip the clutch) the torque at the back wheel will be 10% more. Any ideas why this would be considered more beginner-friendly? Furthermore, my bike is actually 9/40 which another 5% shorter. What gearing does the panel recommend?

I've used the SKF equivalent to repair a worn shaft in a water pump. It lasted twice as long as the original before finally needing total refurbishment. Not sure how it would work in this application though.

Brilliant! Thanks, Mike.

And still the same bike!