gav dt Posted January 26, 2009 Share Posted January 26, 2009 can i fit an over sized piston it to my yamaha dt 50 with not a lot of hasle or expence Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 26, 2009 Moderator Share Posted January 26, 2009 Yes you can, look for Wild Foamy's threads, he did it but unfortunately it didnt last long after that. Link to comment Share on other sites More sharing options...
gav dt Posted January 26, 2009 Author Share Posted January 26, 2009 Yes you can, look for Wild Foamy's threads, he did it but unfortunately it didnt last long after that. would i have to change the head an my cylinder? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted January 26, 2009 Moderator Share Posted January 26, 2009 You would need a big bore kit, this is a piston a cylinder and i think...a head too, ask Wild foamy, he's been there and done that, he will tell you what you need to know. Link to comment Share on other sites More sharing options...
gav dt Posted January 26, 2009 Author Share Posted January 26, 2009 You would need a big bore kit, this is a piston a cylinder and i think...a head too, ask Wild foamy, he's been there and done that, he will tell you what you need to know. ok thank you much apreciated Link to comment Share on other sites More sharing options...
wild foamy Posted January 26, 2009 Share Posted January 26, 2009 you can fit an oversized piston but you would need to get the barrel bored out to accept the extra width, go on ebay, there are big bore kits for about £45 on there, it is basically a 60cc piston and a whole new barrel which replaces your old one, i had one and it was great, used to get 50mph+ from it but didnt jet my carb and it chewed itself up. you will need to rejet your carb, i was originally going up from a 99 to a 115. to get the best use out of it i suggest you also look at getting an aftermarket exhaust and a pod style (K&N) air filter, both of these would require re-jetting (mine already had a filter and exhaust together and came jetted from a 88 to a 99) and are cheap and easy to do if you are wanting more speed then perhaps change your gearing?, the largest front sprocket available i think is a 14t and the smallest rear is a 44t which will give a noticeable increase in top speed at the expense of acceleration. ive tried every trick in the book to get more speed out of my DT and the exhaust is probably one of the easiest ones to do and give a surprising amount of extra power, it lets the engine breathe a lot better and when used with a K&N air filter causes less restriction in the engine, Link to comment Share on other sites More sharing options...
PICTURE_MAN36 Posted January 28, 2009 Share Posted January 28, 2009 Hello Sorry to sound an old sod, but we did all this in the 80's with AR50's AP50's, DT50MX's, TS50ER's et al. We found that yes you could fit 60 & 80 kits, but the bottom end got knocked out in months. Some of the guys we hung around with ran FS1E's with 60 kits, and they could get nearly 50 - 55 mph out of them. Buy far the easiest mod is to change the front pipe, and tail pipe. I had a Honda MT5 (does anyone remember them!!!) and I had a mate fillet the front pipe, and take out some of the restrictor. I also changed the tail pipe for a 'JAMMA' I think it was called, and I managed to get it up to 45 mph without touching the barrel. Changing the gearing only works it your built like a race horse jockey. If you like most people are not 8 stone wet through, changing the gearing will make the gearing taller, but will mean that top gear will only be useable in a back wind down hill!!! If you go down the big bore kit road, it might be worth investing in new big ends, and main bearings dependant on how many miles the engine had done. Personally I'd avoid it as its a quick fix which ends in tears!! Cheers Link to comment Share on other sites More sharing options...
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