anthc123 Posted October 27, 2011 Report Share Posted October 27, 2011 Hi, I'm new to trials bikes as I race quads, me and a few friends have purchased trials bike for over the winter to play around the farm on, I just purchased a 2003 beta rev 3 270 and need to no how much oil to mix with 5 litres of fuel? Also if there is a certain oil I should stick to as it's going to be my first outing this weekend, so all tips or advice is much appreciated! Thanks Quote Link to comment Share on other sites More sharing options...
nzralphy Posted October 28, 2011 Report Share Posted October 28, 2011 70:1 ratio mate, and only use a fully synthetic oil. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted October 28, 2011 Report Share Posted October 28, 2011 If you want your engine to run clean but wear faster go for a lean ratio of 50:1 upwards If you want more power and less engine wear go for a leaner ratio between 25: and 32:1 Choose a fully synthetic or semi synthetic oil that meets JASO FC specification and never go leaner than oil or bike manufactuer recommends. Cheers Quote Link to comment Share on other sites More sharing options...
02-apr Posted October 28, 2011 Report Share Posted October 28, 2011 If you want your engine to run clean but wear faster go for a lean ratio of 50:1 upwards If you want more power and less engine wear go for a leaner ratio between 25: and 32:1 Choose a fully synthetic or semi synthetic oil that meets JASO FC specification and never go leaner than oil or bike manufactuer recommends. Cheers Are you serious? It's 30 odd years since we went to 50:1 with oils inferior to those available today. 32:1 is more than twice the manufacturer's recommendation of 70:1 of semi-synthetic. I can't see how you'd get more power from a motor burning so much surplus oil. It's not a 15,000 rpm racing motor after all. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted October 28, 2011 Report Share Posted October 28, 2011 Perhaps you should ask the question why "we" went to 50:1. Was it on knowledgable scientific research, or was it because of what it says on the bottle or in the handbook and gossip in the paddock? The reasons more oil gives more power even at low RPM are: It provides a more complete oil film reducing frictional losses It Provides a better piston ring seal, raising compression, reducing gas loss on the power stroke and reducing contamination of the crankcase mixture by reducing ring blow by. It lowers piston temperature and distortion as the greater quantity of oil provides more medium to conduct heat from the piston to the cylinder wall / cooling jacket. Lower piston temperature increases charge density giving more power. Over the last few years I have seen quite a few engines with premuture wear and the common factor is that they are very dry / unlubricated inside having been run at lean oil ratios. Remember 2 that if you are mixing at 75:1 and you get it slightly wrong you can soon be at 100:1, get it slightly wron at 30:1 and you will still have adequate lubrication. Also remember that manufacturers are going for lean ratios to reduce emissions, they may not be that interested in engine longevity - they do have spares to sell & profit from. Cheers Quote Link to comment Share on other sites More sharing options...
dan williams Posted October 28, 2011 Report Share Posted October 28, 2011 Depends on what you're doing. If it's normal trials practice where the engine spends most of its time lugging near idle with the occasional full throttle blast 70~100:1 is common. If you and your buddies are ham fisted yahoos that are going to trailride a trials bike like a motocrosser all bets are off and I'd stick to the 50:1. Be warned trials bikes don't handle that kind of treatment at all well and you'll probably kill it in a year. Don't get me wrong I have my ham fisted yahoo days but not as many as when I owned my Maico. Personally if I'm out tooling around doing the trials practice thing I'll run 100:1 with good racing fuel. Betas really do like the high octane of VP C-12. A good quality synthetic oil will do nicely. Any brand really. There's a lot of good info on this site if you dig around. Have fun and welcome to the sport. Quote Link to comment Share on other sites More sharing options...
t-shock 250 Posted October 28, 2011 Report Share Posted October 28, 2011 This question comes up time & time again, the general consensus seems to be that most folk run between 70 - 80:1 using a fully synthetic oil. "dadof2" doesn't take into account that trials bikes simply don't generate the engine speeds or heat to burn off the very excessive oil ratios which he is quoting. You will be unpopular at your local club if you run so much oil that you are smoking people out in the queue for the sections not to mention you will have to clean out and re-pack your exhaust constantly. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted October 28, 2011 Report Share Posted October 28, 2011 Yep, this topic certinly does come up time and time again and causes a fair variance of opinions. I note there was a poll a while ago and certainly the majority expressed a preference for leaner ratios. I suggest that those who have posted since my first post, read my first post again carefully. You will see I made no recommendation,just pointed out the alternatives which did include 50:1 and leaner ie 70:1 ". I can't see how you'd get more power from a motor burning so much surplus oil" was then in the following post so I gave an explanation. Excess oil can have implications for the exhaust on a poorly jetted bike, but if your jetting is correct 25:1 burns off no problem. As for gassing your mates queuing at the bottom of sections, I can only point to the popularity of trials in the 1970s when every one ran 25;1 on much smellier oil than today. From previos posts "Be warned trials bikes don't handle that kind of treatment at all well and you'll probably kill it in a year" - I would agree, you probably would at 80:1. Cheers Quote Link to comment Share on other sites More sharing options...
t-shock 250 Posted October 28, 2011 Report Share Posted October 28, 2011 This isn't the '70's though, things have moved on a bit. Quote Link to comment Share on other sites More sharing options...
durham4416 Posted October 28, 2011 Report Share Posted October 28, 2011 Iv juat bought a beta revs 279 and been told by two trials specialist that I should mix 75-85ml of oil (using putoline tt the strawberry scented stuff ) to 5 litres of fuel Quote Link to comment Share on other sites More sharing options...
02-apr Posted October 29, 2011 Report Share Posted October 29, 2011 (edited) Well, Dof2, we went to 50:1 because that is what Fantic told us to use and there are still bikes from that era running on the original motors. A modern trials bike simply would not run properly at the 25/30:1 level. I've run 70:1 on my 2003 Beta since I got it at a year old and nothing has worn yet, despite taking a hammering across the moors. I agree about accurate measuring though but, rather than use grossly over rich a mixture in case the measure was wrong, I prefer to use a syringe to get it accurate to start with. I checked the measuring lines on a bottle of Ipone and they were well out which would lead to an under provision of lubrication so beware all. The benefits you describe from using "more" oil are indeed valid and can be measured on a dyno but have to be seen in context and bear relevance to racing motors rather than the use to which a trials motor is put. Edited October 29, 2011 by 2/4 Quote Link to comment Share on other sites More sharing options...
anthc123 Posted October 30, 2011 Author Report Share Posted October 30, 2011 Thanks for the replies. Sounds like the 70:1 suits what I'm going to be doing! I have my first outing in the morning so wish me look! I will let yous no how I get on! Lol Thanks Quote Link to comment Share on other sites More sharing options...
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