wright4d

On the cam shaft there is a weight that when at tickover opens one of the valves to reduce the compression (to aid starting etc.) then once the rev's increase centrifugal force throws it outwards and closes the valve. At tickover a small spring keeps the weight in thus holding open the valve. Mine went and it was a horendous knocking noise that when the throttle opened went away. If you do a google search for "beta evo 4t engine manual" and look for a pdf link from American Beta. download this file its the entire engine re-build manual. Look on page 67 the items are 4 & 5 that went wrong with mine. Not saying this is your problem but it may help. I can't get a link to it on here but if you are struggling I can email it to you.

Hi Is it a constant knocking or only at tickover? if it is only at tickover it may be the same problem as my 4T Evo where the de-compressor weight return spring had failed.

Hi All I am looking to get a spare wheel for the Evo 4T (the type with the spokes through the raised flange type not drilled through the rim), seen a few on eBay but mainly from old Mont 315R's any ideas if these will fit with modified spacers, do they need different sprockets (the Mont ones seem to be dished) and will a disc need to be made specifically. Any advice appreciated Cheers

Hi Last year I bought a used Evo 300 4T, I was given a small bag of bits with it (lights etc) which I just shoved in a cupboard. I was tidying up today and looked through the bag and came accross a small packet with the old pilot jet (starter jet as descibed in parts list) with 27.5 on it (definately a used one). The packet had Jet 25 written on it which I assume is now in the bike. What I was wondering is. 1. Is the numbering a direct relation to size i.e is the 25 actually smaller in size than the 27.5 (I know this sounds obvious but it may not actually be the case if it is just a reference number similar to standard wire gauge etc.). 2. What effect would this have had on the bike by putting a smaller (or larger) pilot jet in? Thanks for any advice.

After a big off how much engine oil would you expect to see in the air box ? after the weekend I found quite a big puddle in there. And before you answer don't have an off I just can't help it that's the way it is.

Google just shows the web address and when you click on it it comes up as an error, tried looking on T & MX couldn't find it but thats probably my fault

Hi Does anyone know what has happend to the Wrexham Motorcycle Club website I was looking for some info regarding this Sundays trial but can't get to the website from the links on Cheshire and North West Centre site. Thanks

Try these guys they do different types even a titanium one buts it's very pricey (you have to click through a few pages) http://www.jbanyeres.com/en/12-beta Be carful though you could spend a fortune on other bits if you have low will power some tasty items

Sory meant to say lowered the clip and raised the needle. Just typed in a hurry, the tappits thing is another reason I need a good dealer to service it and try to get the set up right for me. thanks for th replys

Can anyone recommend a good dealer within an hour or so of Cheshire who can set up my Evo 4T can't get it to run quite right after fitting Bosi exhaust tried all the suggestions regarding lowering th carb needle to richen it up etc. but still got very slight flat spot. Cheers

Thanks yes just the back section.

Anyone able advise the procedure and best materials to re-pack an Bosi titanium exhaust for the Evo 300 4T Cheers

I have one fitted to my Evo it was a small piece of strap from an old sports bag. Bolt it through the 2 rear mudguard bolts which go into the rear subframe and do not affect the airbox at all. Make sure you use large washers as well so the bolt don't pull trough the holes in the strap. I also made the holes with a hot nail so that it melted through and does not fray and melted the ends of the straps so they don't fray as well.

Thanks for the info, just re-set as per your advice and it seems ok (only warming it up and then revving it in the garage throughout the range) but it seems to have sorted out the problem. Another good example of the forum coming up trumps. Once again many thanks Regards Derek

Thanks for the advice folks I will try your suggestions, what I noticed today was after washing the bike I started it up and with the choke on there was no noticable flat spot when I revved it. I think this would point to it running a little lean am I along the right line with this ?. If it is then I think the needle suggestion will sort it out. Once again thanks for all the advice. Cheers

Hi All Stripped down the carb on my Evo 300 4T last week cleaned it and put it back on. Now there seems to be a lat spot at about 1/3 throttle. Can anyone think what I may have got wrong? Thanks

Tried Lampkins and though helpful from and avice point of view since it's out of warranty could not help further. Took the plunge and cut the back of between the button welds you can see (one for top baffle and one for bottom baffle). The trouble is that where the large diameter pipe which is welded to the bottom baffle passes through the opening in the top baffle, this hole seems too big and the pipe moves around in the hole and the same for the pipe that is at the top of the back baffle and goes to the outlet. It appears that these need to be loose for thermal expansion of the pipes so it is not as simple as welding them to the baffles in question. I have made some stainless steel shims and wedged between the pipe and the baffle hole to take up the slack. Next I will tack welded the shims to the pipes which will allow the pipes to expand individually in their holes but makes them tight enough not to rattle in their holes and then weld back the shell plate. Before closing I will make sure all burrs are removed since when welding the shell plate back in these will drop of inside and rattle around. I have some pics taken and will post if anyone needs them. Regards Derek

Thanks for the reply was your dad's bike still in warranty when they changed the exhaust mine is out of warranty Cheers

Got a 2010 evo 300 4t with IRC tyre and it goes down if you ride at correct trials presures, if I fit a tube will I need to drill and fit grippers ? or do the tubelss tyres hold so tight that grippers not needed. Worried about ripping out the valve from the tube if tyre spins on the rim Any advice appreciated Thanks

Is it an evo 4T? I have a rattle that seems to be a loose baffle on my 300 4T please reply with a fix if it is the baffle. Thanks

Hi All Hoping to return to trials after a 20 year break (kids, mortgage usual c@@p) thinking of buying the Beta Evo 300 4T. Any info on how it will perform for an over 40 over weight bloke. When I retired I was riding the Beta TR 34 and loved the the thing.