dadof2

Perhaps ND if you actually opened the link and read it you would realise it does not actually refer to Karts, and it has the information fourex was looking for as well as being a useful general read for any one setting up a Dellorto Carb.

If you go onto "Simply Bearings" website they offer a range of quality / price. I generally find so long as they are branded such as SKF or Timken, how long they last is far more to do with maintenance. You can flick the seal out of a RS bearing, rinse it out with 2 stroke mix or WD40, let it dry and re grease it and they last for many years.

Cylinder head joint leaking? Rubber on radiator cap perishing or thinning? Kinked hose or inside of hose coming away reducing coolant flow? Give he radiator a thorough clean inside and out. Check plug colour - has mixture gone weak for some reason? Put a strobe on the ignition, sometimes CDI partial failure can give incorrect timing that causes overheating.

37 years old, at the top level for 20 years plus, totally motivated and still winning in the premier class, even if he retired tomorrow the GOT is surely a well deserved title. Sam Lowes doing us Brits proud as well.

Fitting a gearbox sprocket with fewer teeth, or a larger wheel sprocket will lower the gearing and actually make the bike easier to wheelie and flip over backwards, maybe not what you are looking for.

Its just thin pressed aluminium sheet. When I was in trials where I might expect to lift the bike a bit i used to carry a long fan belt that I could loop through any part of the bike to lift or drag it.

http://danskkartingcenter.dk/dellorto_motorcycle_carburetor_tuning_guide.pdf Make sure the little sprung loaded plunger on the float valve moved freely in the valve, they can get notchy with wear / age and cause the fuel level to vary widely.

Take ibuprofen before you start the trial

You usually need a very good fitting Allen key for the cylinder head bolts. I ground a larger one down on a surface grinder so it was a tap in fit. The primary drive gear on the crankshaft will probably be very hard to pull off, I had to make an adaptor that fitted behind it then used a hydraulic puller.

Agree, there seemed to be starting problems on 300, once it started it ran fine. I wondered if it was the ignition system struggling to generate sufficient electricity at low starting RPM to fire the twin sparks. Until I see the stator and see how the twin spark works I can't be sure if it will lack energy at very low RPM. Once the engine is running and the mixture contains ionised particles from previous combustion, lower spark energy is generally not an issue.

At the time I made my initial post I was not aware Mick Gallagher had died. One of the lads looking over my shoulder has a fair idea who caddy4u is and as I have said already we thought the post was pretty funny as we did it. If you then follow from the insults I received you will see why it progressed into the EFI posts it did. As someone who posts in the way you do ND, you are hardly in any position to lecture anyone else on sensitivity, I would go as far as suggesting diplomacy is not your strongest subject.

http://www.opieoils.co.uk/pv-91954-silkolene-classic-2t-premix-sae-40-synthetic-ester-2-stroke-and-rotary-engine-oil-5-litres.aspx?gclid=CLDqlpGp88sCFfAy0wodClAIBA See above. In 1978 Montesa were advising 24:1, by early 1980s they had changed this to 32:1. Silkoline advises using manufacturers ratios so I would stick with that. Modern synthetic oils for watercooled engines are not ideal for older air cooled engines. To return to your original question. I have used Power 1 (TTS) for extended periods at 33:1 and found it to be excellent. Clean running and so little wear or deposits they may as well be zero. I have friends use A747 at 40:1 for mx and 50:1 for trials, some deposits but minimal wear and reduced engine noise suggesting good film strength and lubrication. Both the Castrol comments refer to watercooled engines.

So long as its not gearbox oil that is burning and your spark plug is the right colour do not worry about the exhaust smoke. 2 strokes can be expected to smoke although modern fuels and oils have significantly reduced smoke. 4 strokes are not supposed to smoke (with a few specialised exceptions)

Part of the solution to this (not just at SSDT) is to set the sections to take minimal marks from the winner and mark strictly to the no stop rule, rather than making the sections hard and then marking over leniently.

I have 6 vehicles with EFI and somewhat more than that motorcycles or plant with carburettors so I am in quite a good position to comment on their relative merits. I also have diagnostics equipment such as scanners, Oscilloscope and injector test equipment for EFI. The main problem with carbs is lack of knowledge of those attempting to work on them. I have a 1997 motorcycle and apart from a balance after running in the carbs have never been touched, I have a 1978 Honda, the carb has been stripped once. On my trials bikes I hardly ever strip the carbs and by hardly ever I mean never or several year intervals. Regarding entry fees - I will post again on that topic.

Cold start enrichment system (often called choke), float valve and float level would be my first checks, after air filter. What grade of plug? What oil ratio and what type of oil?

No need for insults. I made my initial post with a couple of fellow trials riders looking over my shoulder, they thought it was pretty funny. Part of the joke we were sharing was having to send an EFI part away for adjustment, so much for EFI needing less attention than a carb. Both these riders share my views on EFI, fine on their cars but they don't want it on their trials bikes, one owns a GG the other a Beta. Cornishtwinspring calling me a luddite, coming from a twinshock owner / rider that takes the biscuit.

Someone needs a sense of humour implant

Buy a twinshock, no maps to bother about

Unfortunately no longer true. Some of the crap being sold as fuel round here now makes anything knock and even brings engine management light on in cars. Switch to BP or better still BP ultimate and the knock disappears and performance improves.

I would look up the output of your ACG. It may be it does not have sufficient power to get the grips hot.

I too was shocked at the price of cast iron - I was quoted over £100 for a bit smaller than a brake drum a while ago. Cast iron or mild steel will do but the have the disadvantage they will rust and their thermal expansion rate is not as close to aluminium as is stainless steel such as 316L. If you are lucky you may be able to find an offcut of thick walled pipe. http://www.engineeringtoolbox.com/nominal-wall-thickness-pipe-d_1337.html If you can't find the exact diameter you need you may be able to get some solid bar from a flange maker. Or you can get a bit that oversize , cut a bit out to reduce the diameter and weld it. We used to use http://www.alexandercomley.com/

Firstly lets exclude 4T from this discussion, carbs have significant drawbacks for 4T trials engines. Regarding cables vs hydraulic - I am referring to the means of transmitting force, not whats on the end of it. No way am I advocating a return to drums. Once of the variable that now affects the running of engines is fuel quality. The addition of ethanol affects fuel density, carbs automatically compensate for this because metering is to some extent by float displacement. EFI does not compensate for this because fuel delivery is based on volume. Some say they find EFI reliable yet this thread has a lot of people messing about with computers and fuelling maps, If it is so right why does this happen? When a carb is used you have all the fuel system in one cheap compact package, With EFI you have a throttle body, a pile of sensors, a fuel pump, ECU and a pile of wires, extra electricity generating capacity , a pile more wires and possibly a battery. There are two further EFI problems on 2T engines. At this time there are no lambda sensors available that would have an acceptable life span. As the fuel mixture passes through the crankcase containing residual fuel and oil (particularly during varying throttle conditions) the theoretical benefits of EFI can never fully be realised. There are many post on this forum from people who clearly have no idea how to diagnose carburation problems or set up a carb, to them EFI may well give a net benefit. To someone like myself sorting both EFI and carbs is relatively easy in the garage at home, but carbs easier to fix in the field and the EFI needs costly diagnostics.

For some reason oil to fuel ratios seem to be a very emotive topic and I have made some long posts on the subject in the past. I run at 30cc oil to a liter of petrol for trials and 50cc oil to a liter of petrol for MX. I do not get oiling up, poor running, smoking, carbon build up or exhaust clogging. I get much less bore wear and much better reliability than I did when I ran at 20cc oil to a litre of petrol. At very lean ratios 80:1 or 100:1 you may not seize under normal running but that does not mean it is an ideal ratio. Most manufacturers advise between 50 and 65:1 for synthetic oil in a watercooled trials engine. To avoid oiling up the most important thing (whatever ratio you use) is to always measure your mix accurately and set your carburation properly for that mix. I have lost count of the number of times riders have repeatedly moved to leaner ratios (less oil) in an attempt to stop oiling up. In fact each time they go leaner they are making the situation worse because they are richening the petro:air ratio, lowering the cylinder pressure and making the engine run cooler.

I have waited a while before posting again on this. There has now been at least 2 trials this year in this area with £20 entry fees, in 1975 /76 these same events had entry fees of £1 plus an SAE. That represents a rise of near 2000% I have never had anything to do with the financial side of clubs who run trials but I have made flags, end cards, tape, observed, flagged out courses and sections etc. At MX and grass track I have put in posts, roped, put up paling fencing and built jumps with sleepers & earth. All this willingly and for free. Fortunately there are still some trials available at £12 to £15. Looking at the results of a recent £20 trial the vast majority, particularly on the easy course were in the over 40s category, without newcomers the sport will decline. When these event had lower entry fees less than 25% of the entry would be over 40. I know there are more factors than entry fees causing the rise in riders age but I have no doubt finance is a factor particularly among the 18 to 25 age group.