mits007 Posted January 26, 2009 Share Posted January 26, 2009 Been riding around on my baby for about a month and am absolutely loving it!... However, I want a lil bit more "throatiness" from the exhaust.... without the expense of a new exhaust, if its going to pose me problems in the long term, I'll leave it, just wanted some advice / opinions: - http://www.650ccnd.com/drillout.htm http://www.650ccnd.com/pipe1.htm whats the verdict?... Is it worth it?... Will it still pass its MOT?... regards, -Mits- Link to comment Share on other sites More sharing options...
shed hermit Posted January 26, 2009 Share Posted January 26, 2009 you may have to re-jet the carbs as more air out=more air in=weaker mixture. i made new cans for my triumph and they gave me a big flat spot mid-range and were too loud. i then reduced the outlet slightly which got rid of the flat spot and some of the noise and got away with moving the needles up a notch or two. i only made the cans as the old ones were knackered anyway, if yours are good is it worth cutting them? Link to comment Share on other sites More sharing options...
gabby Posted January 26, 2009 Share Posted January 26, 2009 i wouldnt,, if anything i would see if it was possible to cut right round the outside edge , remove some of the sound deadining round the baffle, put the baffle back in and weld the outside edge back on, though it seems like an awful lot of work just for a deeper sound, i dont know about passing an mot with big slots and holes in the end of the can,, would probably depend on where you go for an mot, and whether the guy is deaf or not. Link to comment Share on other sites More sharing options...
shed hermit Posted January 26, 2009 Share Posted January 26, 2009 i dont know about passing an mot with big slots and holes in the end of the can,, would probably depend on where you go for an mot, and whether the guy is deaf or not. he might be deaf after it Link to comment Share on other sites More sharing options...
gabby Posted January 26, 2009 Share Posted January 26, 2009 loud pipes save lives...... you could remove the exhaust cans and just ride it with the downpipes, would definlately be deeper but you will need deeper pockets too to pay for all the extra fuel you would use , jetting it up to cope would be fun, there is a baffle end piece thingy you can get that fits in the end of the downpipe, similar to the baffle in a dirt bike expansion can, a mall hole drilled in the end of the downpipe for the screw that holds it in place ,, try m+p or here here £4.95 not bad Link to comment Share on other sites More sharing options...
dragstardave Posted January 26, 2009 Share Posted January 26, 2009 Hi i got given one of those kits thst were on ebay where you drill the end of the exhaust and fit a big washer over the holes you drilled it did sound better abit and still passed its mot and i did not notice any loss of power now got highway hawk turn downs fantastic!!! Link to comment Share on other sites More sharing options...
Cov_AL Posted January 27, 2009 Share Posted January 27, 2009 I've gone for the drill out option, I've done six 12mm holes in each exhaust. Did it well over a year ago and no problems... I know a fair few others that have done the same too. also, MOT wise they didn't even blink. Link to comment Share on other sites More sharing options...
Cov_AL Posted February 6, 2009 Share Posted February 6, 2009 Link to comment Share on other sites More sharing options...
mits007 Posted February 6, 2009 Author Share Posted February 6, 2009 I'm still umming and arring about mod-ing the exhaust!.. (Too much of a chicken? - don't know) - just the thought of changing something permanently - just out of interest, is there any impact on fuel economy?.. regards, -Mits- Link to comment Share on other sites More sharing options...
shed hermit Posted February 6, 2009 Share Posted February 6, 2009 hi mits if you go for the drilling option you may have to re-jet the carbs, as i said before more air out=more air in=weaker mixture, but the impact on fuel economy would be minimal, you may not even notice it. Link to comment Share on other sites More sharing options...
mits007 Posted February 7, 2009 Author Share Posted February 7, 2009 hi, If thats the case, presumably you'd have to re-jet if you replace the stock exhaust - correct?.. What I dont understand is why the "slip-ons" state no re-jetting is required. Presumably the slip-ons still allow the same amout of air out - ie. same restriction as the stock config?... regards, -Mits- I was sooo close to drilling out 6 off Ø6,0mm holes around the end plate on my stocks!... Link to comment Share on other sites More sharing options...
shed hermit Posted February 7, 2009 Share Posted February 7, 2009 when they say "no re-jetting required" they will mean the main jets. what i meant about the re-jetting was moving the needle jet up a notch or two, this lets more fuel up through the main jet. this should be enough. that is what i done and have had no problem. my biggest problem was getting the f@#*ing carbs out of the triumph!!!! Link to comment Share on other sites More sharing options...
Cov_AL Posted February 7, 2009 Share Posted February 7, 2009 I know a lot of people in the VSOC that have drilled out up to 12mm without re-jetting and no problems... No noticable differance in fuel consumption either. Careful if you start messing with the needles/jets - guessing it could make things worse. (if you do then get on a rolling road and do it properly!) anyway, it's not like your putting 3" straight throughs on... Link to comment Share on other sites More sharing options...
mits007 Posted February 8, 2009 Author Share Posted February 8, 2009 I do see your point, my only concern now is corrosion around the "lip of the hole" after you drilled thru'. Tell me - am I being finicky?!?!.. regards, -Mits- PS, not been out on it this weekend, - was all ready to go - and it started snowing :-( Link to comment Share on other sites More sharing options...
Patrick Yegor Posted February 16, 2009 Share Posted February 16, 2009 i drilled 4 times circular and turned off last camera in my exhaust sound sample: http://yegorka.com/pix/new_bike_sound.mp3 im very happy that i did it, my bike sounds like harley now... Link to comment Share on other sites More sharing options...
Ttaskmaster Posted February 16, 2009 Share Posted February 16, 2009 I'd never bother. Mine works fine the way it is and my riding has thus far kept me quite safe. Loud Pipes sometimes get you noticed. The attention is not always the welcome kind as people don't always give a shit and/or will be purposely evil. Link to comment Share on other sites More sharing options...
Marsinus Posted April 3, 2009 Share Posted April 3, 2009 By all comments I guess that nobody was interested what is going on inside the engine after modifying stock or replacing with after market exhaust. By my knowledge mixture of fuel and air that is one thing and the moment of ignition is the second one. So when you change or modify exhaust so all previous settings should be modified also. If not combustion will take place not only in combustion chamber but in exhaust also and that will cause not only pipes blueing but also burning out of valves and valve sockets and that will lead to further engine damages. Just try to run long distance in burning heat without cool drinks and with mask on your face. I am preparing myself and my machine to exhaust change so I did some research. But I still need to know more What kind of rejet kit I have to use (prefer to do not ruin my wallet) and where around Reading I can find qualified workshop with rolling road. If you have any info please let me know. Link to comment Share on other sites More sharing options...
Cov_AL Posted April 3, 2009 Share Posted April 3, 2009 In the stcok 650 pipes there are 3 baffles, drilling out part of the final one makes very little difference - so there isn't really any need to rejet, especially on such an agricultural engine. I've done about 20,000km since I drilled mine - and it hasn't caused any problems yet! Link to comment Share on other sites More sharing options...
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