southwester

http://www.lewisportusa.com/manuals/beta/Trials%20service%20manuals/2010-2011_evo2t.pdf In the Evo manual they show what they call a heat exchanger which looks as though it sits up inside the inside of the head. As I'm sure you know there isn't a manual for the Rev but it looks like its head has a removable hex as well and I would like to clean the carbon of off it and the crud in the water ways. There's nothing with the new piston, re plated cylinder, my Beta's owners manual or the Evo manual about running it in, as it's all new And it's cost me a good few quid I want to make sure I do it right.

What's the preferred method of carrying out the above as in what pre mix ratio, rev patterns and general break in procedure? It's needs to be done on a Beta Rev 3 250 2007 Also how does the heat exchanger? Come out of the recess in the cylinder head?

Do you need a tool to take off the primary gear or does it pull off by hand after the bolt in undone? My bikes a 2007 Rev 3 250

Hi mate, Have you tried Allen's used trial spares it says on his site he's breaking a 2006 Rev or other than that can't some one order you one from Beta?

I thought you and others may benefit from this answer. To: <info@beta-uk.com> Sent: Sunday, October 20, 2013 9:38 PM Subject: Rev. 3 250 2007 Hi can you help me with these questions? Some people where I ride have told me that the spacer between the inlet manifold and reed block can be removed to aid getting carb in and out, is that right and does it effect performance? IF IT IS A 2T JUST REMOVE. IT WILL MAKE A SMALL DIFFERENCE GIVING MORE POWER.

Also have a look at this if the powers that be allow (tis for the good of the sport) http://www.thumpertalk.com/topic/347305-is-your-two-stroke-running-rich-read-here/

I found this on thumper talk seems like the most common jetting issue that comes up are pilot circuit related.the following is a sure method to choose the needed changes. with the bike warm and idleing turn the fuel screw in till the idle drops/misses.then go back out till the idle peaks/smooths. this should happen between 1 and 2.5 turns on a fcr carb and 1 and 3 turns on a cv. if you end up at less than 1 turn you need a smaller pilot jet.more than 2.5 (or 3 turns on a cv) you need a bigger pilot jet. choose the appropriate size and retest. This post has been promoted to a wiki

zero, don't jinx it lets just say I'm keeping everything crossed! I have a new stat, what would the symptoms be of leaky crank case seals or bearing seals do you mean. No mod's that I know of. I was thinking of splitting cases but not confident to do it myself and the bike shop local to me wanted 8 hrs @

Cheers Dadof2 should get cyl ect back this week just eating for cooling hoses to come in and there sending back.

Cheers Dadof2 should get cyl ect back this week just eating for cooling hoses to come in and there sending back.

Hello fellow enthusiasts can anybody out there lead me to a resource on checking jetting by plug chopping or describe the process. The reason I ask is because I bought my first trails bike Back in August and I have had a bit of bother with it. When I first got the bike a 250 Rev 3 it had a 35 pilot jet a 150 main and needle clip on second notch from the top, it was pinking on throttle chop and leaking fuel, I had carb drilled out to stop the leaking and the shop that did it said that the 35 jet was in there to mask another problem and sent it back with a 30 in there and needle clip in the mid position, the next time I rode it the radiator thermostat packed up and it over heated exhausting coolant. When I got home I linked the two wires together bypassing thermostat and fan was working so thought all was good, I also drained coolant at this point just to see what it looked like and on refill squeezed hoses to vent any air out(it looked ok by the way no bits or anything) I assume at this point the white chalky substance that turned out to be through out the waterways caused a blockage somewhere in the system and the next time I rode it over heated again, the fan was still running. Some one where I was riding said have a look at the pump impeller and when I took cover off it revealed the inner clutch case was corroded and the impeller area was full of the white substance. I removed head, cylinder and hoses to find this crap was throughout and the piston and cylinder didn't look that good to me, anyway after posting some pictures up in the Beta thread and then having the shop take a look they said it needed a re plate and a new piston. Also the new plug I put in when I got carb back was white but the previous plug was the right dry chocolate brown colour. So when I put it back together I want to check to make sure it's running ok. Thanks in advance for reading mine and my bikes life story and any replies if you are still awake or aren't off to top yourself!

No mate that's part of the clutch, master slave cylinder I think?

Ok dadof2 sounds like a good plan I will get some hollow solder and have a larger bowl of sugar puffs in the morning! When you mentioned about doing mains and seals to be good for 5 years you got me thinking, I might well go for that while I'm so close for piece of mind although I can't detect any up and down play through fly wheel or con rod at 6 and 12 o'clock. So to do that I would need a tool to hold clutch basket to undo nut? and would I need any other specific tools to split cases ect or do they pull - pry apart with the aid of the cut out to the front of the engine as one of the pictures I previously posted. Another thing I haven't mentioned yet is when I bought the bike the jubilee clip that go's round the rubber that attaches to inlet of carb was undone and I didn't realise until I had already riden it for a few hours, a fellow rider where I was riding said the bike sounds like it has a air leak so I checked what I could see and that was undone, it turned out afterward he ment downstream of the carb unbeknown to me initially, after when I got the bike home and stripped carb down there was a fair bit of crud in the bowl and like previous posters have mentioned there were signs on the piston-cylinder of crap entering. Also at that time I had air box ect off and it had holes drilled in it and plenty of dirt in. So really I got to split cases just to get any crud from the bottom end haven't I. Thanks for your input and to the site in general its a invaluable sorce for a novice trialer and mechanic.

I had some ds40 central heating cleaner lying around which is suitable for cleaning boilers with aly heat exchangers so I submerged rad and water pump cover in a solution of that today which has dissolved the gunk totally. The cylinders off at the re platers and I'm hoping the water ways will come back clean so I won't need to touch that. The hoses were lined with this crap but where in the past some ones got a bit heavy handed tightening the jubilee clips that part of the hose's are crushed and there's some cracking of the rubber so I am going to get a set of replacements to put on. Going back to checking the squish clearance is the technique to torque the head down with gasket in place and torque cylinder down with out a gasket kick engine over and take measurement of solder add on thickness of base gasket and that would tell you what thickness of gasket(s) to use, other wise if you install gaskets and torque down to find out your squish isn't to spec you are another

That stuff's a reaction between different coolants is it? makes sense, I couldn't figure out how it got there I wondered if it was rad weld or something. It seems to have coated the parts of the cooling system and there were clumps of it within rubber hoses and actually there were some lumps in cylinder. I've submerged the water pump cover in petrol and fairy liquid so far to try and dissolve it to no avail but I dropped a flek of it in some watered down spirt of salts and that dissolves it pretty quick but it says on the tin not to use it on aluminium so I need to find something Ali friendly that I can rely on to clean waterways in rad with out visual inspection. Would you or anyone else have any suggestions how to shift it? As for replacing main bearings and seals I can't detect any play through fly wheel and there isn't any oil leaking through seal behind fly wheel by the look of it but when I took sump guard of the bottom of bike i noticed a lot of oil over the bottom of the engine and the rubber matt the engine sits on which made me wonder if the crank case seals were leaking oil, I just got the vibe it wasn't from where the oil has been drained off previous. Also the coating on engine cases had bubbled where the cases meet which I scraped off previous to pictures which suggests to me the same and finally it looks like someone's got got the flat head out to prize the casings apart which is really making me wonder? The engine isn't off the bike yet but I'm only 3 fixings away, all comments welcome. Cheers

Thanks for the advise dadof2, I will. Well I got in touch with the shop I bought the bike from and although the owner said he isn't accepting liability he has agreed to send me out a piston kit so at least it's something towards the cost of the replate ect.

thanks for the further replies. My local trials bike shops mechanic has taken some measurements and done a visual and he said it needs a re plate and new piston ect. He reckons the marks on the piston are consistent with piston slap rather than anything breaking up so that's at least some good news. About

Thanks for the pointers. Neil I linked out stat when it packed up the first time the bike over heated because the fan came on after 30 seconds of engine starting and thought fan may as well be on full time. But it turns out the fan was coming on quick because the waterways throughout the system are partially blocked with emulsified oil getting in from the water impeller seal where the dreaded electrolysis has taken place. Oddly enough there was no sign of water in the gear box oil. Why do you ask mate?

Here are some pictures of my 2007 rev 3 250's top end, I have had it off to clear out water ways in cylinder and head and thought I would post some pictures of piston ect. Having no experience of engines I don't really know what I'm looking for damage wise, there are some light scratches on inside of cylinder but arnt deep enough to feel with your nail so from other posts I have seen on the site I think this is ok. The piston has the same sort of light scratches but again can't be felt with my finger nail. There doesn't seem to be any up and down play in con rod or fly wheel so mains seem to be ok. Are there any checks I should do like measure tolerances of piston rings and cylinder bore and what's the usual good practice when rebuilding top end obviously new Gudgen pin circlips but would it be advisable to replace small end bearing and Gudgen pin also. Unfortunately I didn't check for any play in small end bearing when I took the barrel off. I have taken rings off piston now aswell so is good practice to replace

Its about 6mm mate, I've read people have taken them out to make it easier to take out the carb but if you mean does it make any difference to the performance? I don't know. I recently striped all mine out I think Beta have missed a gasket off the parts diagram because you would end up with the two metal faces of the reed block and spacer with no gasket between them.

Hi, I cant find any info to see whether my clutch plates are worn below there minimum thickness and don't know what thickness a new set is? and also minimum clutch spring length, I have it all apart so thought I would do it while I'm here. Its a shame Beta don't seem to have this sort of info printed anywhere or that I can find any way I saw a link on here the other day for Evo spec's but there isn't anything for the Rev 3 and knowt in the owners manual. Can I use the specs for the Evo on the Rev 3? If any body can help please do, If not I will contact Beta and post results. Cheers.

Thanks Dan!

Google the "trials training centre" and click on the how to ride tab, there's a lot of information on there. As a beginner myself I found it really use full. Good luck!