oldnslo Posted July 13, 2014 Report Share Posted July 13, 2014 Good fuel is very hard to come by in my area. Any easy way to reduce knocking? The only ones I can think of is adding base gaskets or retarding timing. Thanks. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted July 13, 2014 Report Share Posted July 13, 2014 Get some octane booster additive by mail order. Quite a lot of companies supply it. Complain to Koch industries in Wichita, they have quite a bit to do with fuel refining. Quote Link to comment Share on other sites More sharing options...
oldnslo Posted July 14, 2014 Author Report Share Posted July 14, 2014 I live in Kansas and that statement is not true. The true culprits are actually the big food corporations like Archer and Cargill (just wait, Monsanto is after you guys too). Anyway, this isn't a political forum. I have a bit of an issue with fuel additives because I have the long range fiberglass tank. I didn't run ethanol because of this but I've moved to an area where I have no choice. I'm using Startron fuel additive to reduce the lilihood of ethanol damaging the fuel tank but that still leaves me with octane issues. Most additives have some form of alcohol in them, the last thing I need. Because of meth producers toululene and zylene are a tad more difficult and expensive to buy now too. It seems a mod to the bike is a good solution. Quote Link to comment Share on other sites More sharing options...
copemech Posted July 14, 2014 Report Share Posted July 14, 2014 (edited) I am sort of surprised you can't find non alcohol laced fuel up there, but I will throw out a couple of suggestions for you.If this is a dellorto carbed bike, go up on the pilot jet. might try a 36 or a 38, then adjust mix screw down accordingly to about 1.5 - 2 range..Other thing, go get you some 100 octane Avgas at a small local airfield. It is the real deal, but the TEL in it does not hurt a 2T motor, or your tank!Is this the bike some fellow up there was trying to sell a year or so back in cherry condition? Edited July 15, 2014 by copemech Quote Link to comment Share on other sites More sharing options...
dadof2 Posted July 14, 2014 Report Share Posted July 14, 2014 (edited) The "complain to Koch" was intended as a bit of a Joke. But Their headquarters are in Wichita and they do have a fair bit to do with the oil / gas / ethanol industries and refining. http://www.holden.co.uk/displayproducts.asp?sg=3&agCode=0180 Shows the sort of stuff you can get in the UK and they do work in 1870s and 80s MX engines. TEL(Tetra Ethyl Lead) additive is probably getting hard to get hold of these days for health reasons. Retarding timing and lowering compression should work but will reduce power, I would try as copemech suggests, richening the mixture initially. Edited July 14, 2014 by dadof2 Quote Link to comment Share on other sites More sharing options...
clay Posted July 14, 2014 Report Share Posted July 14, 2014 (edited) Mines really fussy with fuel to, but it might be worth checking the head, for any carbon build up. And I'm not 100% sure that you can retard / advance the timing, With it being a fixed unit. Hope you sort it bud. Edited July 14, 2014 by clay Quote Link to comment Share on other sites More sharing options...
oldnslo Posted July 15, 2014 Author Report Share Posted July 15, 2014 I am sort of surprised you can't find non alcohol laced fuel up there, but I will throw out a couple of suggestions for you. If this is a dellorto carbed bike, go up on the pilot jet. might try a 36 or a 38, then adjust mix screw down accordingly to about 1.5 - 2 range.. Other thing, go get you some 100 octane Avgas at a small local airfield. It is the real deal, but the TEL in it does not hurt a 2T motor, or your tank! Is this the bike some fellow up there was trying to sell a year or so back in cherry condition? 100ll won't cause any issues with fouling or anything? Going up a bit on the pilot sounds like a good idea. I'm much more familiar with PWKs then the oddball on this bike. I may try a PWK28 on it just for the tuning. I was going to sell it about a year or so ago. Still has nubs on the tires. Adrian at Lewissports said it was the last 315r imported into the US. I've been riding a 500exc and a Beta 300rr for a while but I think I can start riding it again. Quote Link to comment Share on other sites More sharing options...
copemech Posted July 16, 2014 Report Share Posted July 16, 2014 It seems to me those things as well as other bikes were tuned for high octane and fuel is an issue. I have used 100LL for years with no issues other than HOT weather hot restarts. It runs clean and stores well. The Dellorto is a simple carb and just works and is reliable. Best I recall, they only sold 7 bikes that year here. I still would not mind having it if you decide to sell, but not at a high price. I was just looking at a 2003 clean bike in UK for $1200 as example. But let me know if you decide to do something with it. Quote Link to comment Share on other sites More sharing options...
marky boy Posted July 16, 2014 Report Share Posted July 16, 2014 (edited) I was just looking at a 2003 clean bike in UK for $1200 as example. Really? Link then please Copemech Edited July 16, 2014 by marky boy Quote Link to comment Share on other sites More sharing options...
axulsuv Posted July 16, 2014 Report Share Posted July 16, 2014 As Copey said AVE gas is the way to , leave the bike alone and try some . I run it in all my trials bikes (except the reflex , it gets eth free pump gas , like my lawnmower !) . The ave gas is fine in any tank , and will store indefinitely . Well worth the effort . Glenn Quote Link to comment Share on other sites More sharing options...
copemech Posted July 17, 2014 Report Share Posted July 17, 2014 Really? Link then please Copemech http://www.trialscentral.com/forums/garage/vehicle/923-montesa-315r/ Quote Link to comment Share on other sites More sharing options...
martin belair Posted July 17, 2014 Report Share Posted July 17, 2014 It seems to me those things as well as other bikes were tuned for high octane and fuel is an issue. I have used 100LL for years with no issues other than HOT weather hot restarts. It runs clean and stores well. The Dellorto is a simple carb and just works and is reliable. Best I recall, they only sold 7 bikes that year here. I still would not mind having it if you decide to sell, but not at a high price. I was just looking at a 2003 clean bike in UK for $1200 as example. But let me know if you decide to do something with it. Cope is right, the DellOrto is a great carb. Get some higher Octane fuel and/or bump up one on the pilot jet. The 315R wants good gas. Cope not sure where you got the idea that only 7 were sold that year, maybe only 7 sold in your club. We sold over 200 315's in 2004. Not sure how one bike could be considered that last one imported as they came in shipments with 24 bikes per container. Quote Link to comment Share on other sites More sharing options...
copemech Posted July 17, 2014 Report Share Posted July 17, 2014 Cope is right, the DellOrto is a great carb. Get some higher Octane fuel and/or bump up one on the pilot jet. The 315R wants good gas. Cope not sure where you got the idea that only 7 were sold that year, maybe only 7 sold in your club. We sold over 200 315's in 2004. Not sure how one bike could be considered that last one imported as they came in shipments with 24 bikes per container. Martin, you would know, but when I said HERE, I meant in the USA. I thought you were the one that gave me that number 7? Oh well, at one time I knew where 3 or 4 went, but cannot recall. Quote Link to comment Share on other sites More sharing options...
oldnslo Posted July 25, 2015 Author Report Share Posted July 25, 2015 Not sure how one bike could be considered that last one imported as they came in shipments with 24 bikes per container. Adrian said it was. I have no idea myself. Quote Link to comment Share on other sites More sharing options...
b_42woody Posted August 5, 2015 Report Share Posted August 5, 2015 (edited) Does / Did somebody make a low-compression head for the 315? S3 and VHM make very nice looking replacement heads with replaceable inserts, but it doesn't look like they make one for the 315. Adding base gaskets to lower compression might work, but you're also increasing squish clearance and altering port timing - two things, if taken too far, which can lead to unwanted results. Reducing compression by increasing combustion chamber will result in lower power, but will it have a major impact on riding? That's up to personal preference. My 2000 Sherco 2.0 gets the job done 'real good' on pump gas without knocking. Toni Bou would feel differently. Edited August 5, 2015 by b_42woody Quote Link to comment Share on other sites More sharing options...
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