harryharls

Just looking at some Boyeson carbon reeds on a website, the description of their benefits looks kind of related to the issue: Boyesen Reeds Carbon Tech for Beta Evo 250, 290, 300 THE BENEFITS:- Quicker throttle response and acceleration.- Easier to Ride, crisper Low RPM riding.- Crisper, smoother transition from Low to Mid.- Connects your hand to the power.- Longer life - Boyesen Power Reeds outlast all other aftermarket reeds.

Thanks for the replies, I'll disassemble the carb and give it a clean out...thanks for the tip about the rubber seal, does the jet tower have to be removed? Does it have to be removed to access the jet? In terms of the way it runs, it starts, runs and idles perfectly without any issues at all. It's just that I feel it's a bit slow to respond sometimes, it can catch me out when navigating an obstacle and I need a quick response. I know these UK models have the flywheel weights fitted, could this slow the response at low revs? Thinking about it, another thing I notice about this engine is that it's very slow to return to idle after being revved high (in neutral), I presume this is the flywheel weight but could it (and the slow response) be a symptom of a leaky reed valve?

Hi, My Evo just seems to be a bit sluggish at times in terms of throttle response. On some occasions when I want to blip the throttle to hop up over a log or double blip over an obstacle it just doesn't respond quite as I'd like it to. I'm going to strip the carb down to give it a clean and while I'm there I'll check the reed valves. Has anyone got any suggestions for what it might be other than this? I can't seem to find any info for stock/standard carb settings for it, I'll check the jet types whilst I clean the carb but without stock info I don't' know if they're the right jets or not! If anyone could let me know what standard jetting settings should be that would be brill! Cheers, Marcus

Ha, broke mine today! A few posts back (last year) I wrote that I hadn't but that I probably would now....well now I have. £70 quid to replace :-(

Hi all (and Dan), I need to update on my last post from last year...I previously posted that I'd done the fix and the results were good at the time, but after having not ridden my 2014 Evo 250 since last year, the clutch seems to be as bad as ever! It's dragging horribly again. I've been out practicing in the woods a few times this spring and the old clutch gremlins are back; dragging like mad at times (sporadically but more often than not) and pretty much impossible to find neutral. I can't understand why, it's just been sat in the garage. I could try changing the oil for fresh oil but surely this can't be the answer, after all; the glue between the friction pads on the plates can't have reappeared! I'm using Putoline light gear oil btw. On another note: Part of what led me to the 'Beta clutch fix' initially was that my bike makes quite a loud and disconcerting high pitch whining noise once it's in gear (with clutch either in or out). This noise is only evident when in gear, when it's in neutral there is no whine at all. Has anyone got any idea what this whining noise could be?? It's driving me crazy, it's got to be something obvious. I presume that because it only occurs when it's in gear (with the clutch in effect...either engaged or disengaged) that it's got to be a clutch related issue. I feel that it's the friction plates themselves, I would really love to get to the bottom of this whining noise as I strongly suspect that it is contributing to the clutch drag issues! I think the whining is loudest when a gear is first selected and during take-up but it's there even when the clutch is fully out, albeit to a lesser extent. Can anyone help?

I bet you were reluctant to practice!!!

The hour meter is a great idea, thanks for that. Trapezeartist...I don't like the sound of that maintenance schedule!! They must have been seriously tuned!

That's good to hear! I've had plenty of bikes in the past and it may be wrong but I only really ever did anything like that when I thought something didn't sound or seem quite right. I think I'll keep a record of how many hours I do because I really have no idea at all.

In contrast to the other replies, I've yet to break mine but I probably will now I've stated that!! I bent my rear one right back past 90 degrees this weekend but it just popped right back with barely a crease; I was quite impressed with it for that :-)

Hi, I have an Evo 250 2014 and I don't know it's history in terms of how it's been looked after. It's absolutely fine with no problems but I've been looking through the manual and the scheduled maintenance guidelines surprise me to say the least! Obviously I keep on top of filter cleans and oil changes, fork oil etc. but it states to replace the reed valve after 80 hours then again in 200 hours. It's the same schedule for piston rings...and the piston itself!! The water pump fan (what exactly is this, is it the impeller in the pump?), water pump fan and water pump shaft seal have an even more regular suggested replacement at 80/160/240 hours. What is even more surprising than all that is the suggestion that the con rod and main/crankshaft bearings should be replaced at 120/240/360 hours. Surely not! Does anyone actually do this; remove and split the engine to replace these parts so regularly? These aren't quick jobs. I'd be really interested to read the thoughts of other Evo owners on this. Cheers, Marcus

Firstly, thanks Dan for an awesome and innovative write up. I've read through the entire thread with interest. I've just completed the work and without having tested it properly outdoors, my first impressions (in the garage) are that it seems to have totally transformed the clutch :-) I have a 2014 Evo 250 and the clutch wasn't great, hence why I arrived at this thread. As with others I found it almost impossible to select neutral whilst running, to the point where I'd stopped bothering entirely and would simply kill the engine at rest. It was also dragging at times, strangely not always, but inconsistently (which is probably worse!), at times it would actually push/slide the braked front wheel across the ground! It was pretty much always difficult to roll backwards with the clutch disengaged too. My clutch pack had the different (thicker) first and last friction plates. These two plates were significantly worse than the others in terms of the build up of glue/friction material between the pads, perhaps these are made by a different manufacturer?? The other four plates were a lot better, almost to the point of not needing any work tbh but I did them anyway whilst I was at it. I carried out the work in the following way: I used needle files as you suggested to clean between the pads and under the tabs (above the pads) to bare metal. The gaps between the pads on the thicker end plates were much thinner than the other four. I used a file to smooth out the tab edges and also to create a small radius on the edges. I finished off by sanding the tab edges with a small block with 600 grit emery to smooth them further. It didn't take too long at all. Finally I washed off the plates and steel discs again in the sink with washing up liquid and water and rinsed well. I don't think I rinsed well enough though as when I refitted and filled with oil (Putoline light gear oil) and ran the bike the oil seemed to be foaming very slightly (seen through the sight glass) so I ran it till hot and drained the oil and refilled with fresh oil as I thought it might be residual fairy liquid on the friction material! Initially I couldn't feel much difference but once it had run for a while and I'd worked the clutch the difference was obvious; There is now absolutely NO drag at all, it will roll backwards with ease with the clutch lever in and neutral can be selected from either first or second with ridiculous ease, it's bloody brilliant Dan! I let it cool down and tried again from cold and it was perfect right from the start. Thank you so much, can't wait to test it out fully tomorrow :-) All the best, Marcus

Oh just another thing, has anyone got any thoughts on what I think I've read about Gas Gas suggesting that Silkolene oil should be avoided?

Thanks Sting and Copemech, really good advice. It certainly makes sense actually that it's just burning off accumulations of oil. I think the way forward is to have a look and possibly clean the exhaust system anyway just for peace of mind and then make sure the tuning is correct and stick the choke on when on the road. Brilliant help everyone, thank you so much

That's a very good point Ben, some things are so obvious once pointed out!! With the exception of motorcycles, the majority of 2-stroke engine applications require running at constant speed. You're probably right about the restrictive exhaust design but one might at least expect to be able to do a few miles on one of these things, especially considering they provide the high 5th gear which is obviously only intended for such use. Therefore a thorough check and clean of the exhaust system, correct tuning and use of the choke on the road should hopefully be the answer. I just need to get the science technician at school (I'm a teacher) to make up some NaOH solution for me to clear the exhaust sections

Thanks Larry, I didn't realise a choke was also called an enriching device. I will try it with the packing removed before repacking too

Thanks Ben, I'll have a look for the burning out method. I've found the previously mentioned link to the Scottish Six Day Trial prepping advice and it does indeed suggest using the choke: 14. YOU MUST USE THE CHOKE ON THE ROAD. Keep easing off to the ‘rich’ spot is the best technique. Tip; vary your speed and throttle when you are on the road. Holding the throttle in a constant place on any 2 stroke is fatal. The engine will run very weak, detonate and easily seize up. Always ride a long with a finger hovering the clutch lever. If you feel the engine tighten or if the piston ‘nips’, pull that clutch lever fast ! If you seize the piston, don’t panic. Let the engine cool down a little and try and push the kickstart down. If the kickstart is absolutely solid, you are in trouble ! The cylinder needs to be removed and renewed with a new piston. If the kickstart will push down, you’ve been lucky. Start the bike and carry on, steadily for a while. The engine will rattle but usually quietens down after a few miles. http://www.motomerlin.co.uk/blog/wp-content/uploads/2011/03/GG-Pro-SSDT-2011.pdf I think a combination of all the above (except perhaps the spark plug) should help/solve the problem. I'll keep you posted on the results, could be a week or two though!

Oh btw, any advice on how to clean the system if it is coked up excessively?

Good thinking Ben, that certainly makes sense to me and well worth a try. Looking at the plug, it looks lovely, no untoward signs at all, no fouling, no signs of excessive heat so it could actually be literally just the exhaust that's getting too hot and, in fact, the engine running at an acceptable temp...hence the rad not boiling over! I'll whip the exhaust system off and have a good look. Larry: Interesting thought on the enriching device. The choke is basically an enriching device, could be interesting to see if running with the choke on helps. But I'll try the exhaust tip first. Brilliant advice chaps

Thanks for your reply Larry. I had no idea that you got hot/cold variants of plugs! The manual states an NGK BPR5 ES, mine has an NGK BP5 ES, basically the same I think (R is for internal resistor or something I think). Could you suggest a plug that runs cooler? Shouldn't the stock plug be correct though? I'll certainly be trying it with less oil in the fuel and I'll tune up the carb to make sure it's not running lean in the meantime. I'll also order the BPR5 ES plug and try that too unless anyone's got a better suggestion for the plug type. Ah, just Googled NGK spark plug codes and I see that the number (5) relates to the heat rating (low being hot). Perhaps a 6 then?? Nice tip on the burning oil smell, I must admit I was wondering about the source of the smoking oil. Many thanks

Hi Guys, My first post on here, I'm hoping somebody can help as there is so little information available on the web for Gas Gases of this age. My old (but reliable) year 2000 250 (249) TXT runs absolutely fine generally but I've very recently road registered it and this overheating problem has only reared its head since I've taken it on relatively long runs (only a few miles though!). I noticed that it gets extremely hot on the road, and only at low speeds really. So much so that it actually smokes from the exhaust, not normal 2-stroke smoke, but hot smoke smoke! It smells like burnt oil...you know, bloody hot oil! The whole exhaust system is ridiculously hot, far too hot to touch, even the silencer. So hot that it's heating up the frame (and petrol tank!!) around it. Strangely, the radiator isn't boiling over but the fan is running of course and it must be close to boiling. I'm sure that the water pump is working correctly too, I've inspected the vanes and the circulation of heat seems fine through the pipe and rad. My thoughts are... I've been running it at a fuel/oil ratio of approx 50:1. After researching it seems that this might be excessively high, perhaps it should be 80 or 100:1 but again, information online is hard to find. Could this alone be the cause of the overheating (causing a lean running condition)? I've also been using Silkolene 'off-road' 2-stroke oil, I've read somewhere that apparently Gas Gas suggest that Silkolene oil should be avoided, is this true? I've come from enduro on a 2-stroke KTM where 50:1 and Silkolene oil have been absolutely fine. Any advice anyone? Many thanks in advance