yammafan Posted June 17, 2014 Report Share Posted June 17, 2014 So I was out on my 06 2.9 and a fellow rider commented on it being quite smokey from the exhaust. I'd only been riding about 15mins so thought it may still be cold. I carried on and it didn't really clear up. I know you can't split the silencer without having to weld it back together and a replacement ain't cheap. Has anyone had the same problem and will it only be excessive oil in the silencer packing, or could it be something worse? Also I've heard people at trials mentioning about 'clearing it out' but didn't understand what they meant (as you can tell I'm new to this!). Is it just a case of full revs when the engine is warm to clear out any carry over? Quote Link to comment Share on other sites More sharing options...
taffe Posted June 17, 2014 Report Share Posted June 17, 2014 Hi, I repacked my muffler by cutting a window in the front and riveting an aluminium plate with metal putty back over the hole. You can't see it as it's under the plastic heat shield. The muffler was full of soggy matting that you could ring out. After 5 years of neglect by the previous owner it was well worth doing. Cheers Taff Quote Link to comment Share on other sites More sharing options...
copemech Posted June 18, 2014 Report Share Posted June 18, 2014 Smoke comes from oil burning, there are a few ways. First would be excess oil in the fuel. I normally prefer an 80:1 ratio of good synthetic in the mix for normal trials use putting about and on the loop. Second, after some good running with heat into the motor and exhaust, you mat start to get enough heat into the muff to actually burn off the excess that has accumulated there. Many bikes may smoke hard after a fast run or a long hard pull on an uphill under high engine load. Third, Bike may be pulling excess oil out of the gearbox side due to faulty crank seals which would not be uncommon on an '06 bike due to age. Preferred replacements would be the alcohol induced fuel resistant Viton ones from Splatshop. Can be done without splitting the cases, yet requires some tooling. Ps- I recco a good blow and go on every ride to keep things cleaned out! Quote Link to comment Share on other sites More sharing options...
yammafan Posted June 18, 2014 Author Report Share Posted June 18, 2014 Taffe - sounds like it might be a good option. do you have any pics? Copemech - I've been running with full synthetic at 2% as it states in the manual but sounds like 50:1 is too much oil. I'm a complete beginner so not riding the bike or revving hard. Should I give 80:1 a go based on the riding I do? I know there's LOADS of threads on premix so don't want to get too deep into it! Also a go and blow? I take it you mean a good fast run to get it hot and clean it out? I notice some people at trials giving full revs when stationary or before a big climb, does this achieve the same thing? Thanks again for the advice. Quote Link to comment Share on other sites More sharing options...
taffe Posted June 18, 2014 Report Share Posted June 18, 2014 Hi Yam, yes I have pics I'll check out re how to post them. Cheers Taff Quote Link to comment Share on other sites More sharing options...
taffe Posted June 18, 2014 Report Share Posted June 18, 2014 Hi Yam, lets hope this all come out, first time posting pic's on this forum. As I was not sure what to expect I cut the first hole too small so cut another to get better reach, even then it was still a pain to get all the soaked material out. There's a pic of the different tools I used to get the crap out. The pieces I cut out were reused to fill the holes but with an oversize piece of alloy sheet riveted to them to leave a flange to create a better/ stronger seal. Using the metal putty and rivets I hoped to be able to gain access again in the future, if I re-welded things would be harder. It made a huge difference to the power of the bike so definitely will do it regularly. Hope this helps, good luck. Taff. Quote Link to comment Share on other sites More sharing options...
taffe Posted June 18, 2014 Report Share Posted June 18, 2014 It worked, too easy. Cheers Taff Quote Link to comment Share on other sites More sharing options...
yammafan Posted June 18, 2014 Author Report Share Posted June 18, 2014 Great work Taffe! Excellent pictures. I'll defo have a go at this as the packing is 8 years old! Thanks again. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted June 18, 2014 Report Share Posted June 18, 2014 Smoking from exhaust is more to do with type of oil (quality), carburation and type of use bike is subjected to. I use what many consider to be a very rich oil ratio (30cc oil per 1000cc petrol) but I use a decent fully synthetic and get hardly any smoke. My strimmer which uses the same fuel / oil produces no visible smoke even when running flat out for long periods. Quote Link to comment Share on other sites More sharing options...
copemech Posted June 19, 2014 Report Share Posted June 19, 2014 (edited) One may debate this mix ratio thing all day, and the fact Dodof's strimmer does not smoke is within the fact it is revving hard all the time! Not much excess to burn off! Yet, as he states, even at the higher ratios(more oil) things do not typically smoke a lot with modern synthetics because it just does not really burn, the excess may be eventually deposited in the muff of a Sherco and build up though, which is why I prefer to give the bike a good run periodically to get heat into the muff and blow things out, as they were not designed to be re-packed, and are a PITA! Dadof's first sentence re- quality brings me back to the crank seals, as this oil mixed in is not designed for the combustion process and will smoke in excess. Couple of quick ck's would be bring motor to temp, pull trans vent hose below carb up to tounge and see if you detect vacume. Or, install small clear hose and see if it pulls water out of a cup. Might drain the tranny just to see how much comes out! 450 in = 450 out if things normal. M2C ps- O yes, the upper class riders will indeed rev them out briefly to insure the excess accumulated in the bottom of the motor does not inhibit a full power blast when needed, after putting about! As well as getting heat into things! Keeps plugs from fouling as well. Edited June 19, 2014 by copemech Quote Link to comment Share on other sites More sharing options...
dadof2 Posted June 19, 2014 Report Share Posted June 19, 2014 (edited) http://exol-lubricants.com/data_docs/TDS%20M124%20Optima%20Racing%20Two%20Stroke%20-%20Iss%205.pdf Have a look at the above, this is why my engines don't smoke and don't get exhaust clogging. The oil is ashless and meets the D (low emissions) specifications. A flash point of 140 degrees means the oil does burn in the combustion chamber but not on the cylinder walls. Edited June 19, 2014 by dadof2 Quote Link to comment Share on other sites More sharing options...
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