pedroply Posted June 15, 2018 Share Posted June 15, 2018 So I got my xt 125 back when I was 16 it was cool but always wanted a bit more power... Now 4 years later I’m doing some experiments on her! Heard of those arrow exhoust pipes got one and felt a bit more power! That got me into doing more modifications to it! Has I couldn’t find much about it decided to create this thread here to post my conclusions. Currently I have on the way a different jet kit (110 main, 17,5 pilot) and a big bore kit 150cc all this parts are Chinese lol probably not the best idea but that exhoust was rather expensive... I have read a bit and learned that some people are against modifying this bikes saying there are no gains to be made and the bike will get very unrealiable but I decided to give it a go. Let me now what you think! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 15, 2018 Moderator Share Posted June 15, 2018 Fair play for having a go. You do need to be aware that these things very often turn into money pits, not to mention the licence element. I know the odds of being caught these days are very low and your not going to be doing 90mph on a 4st 125 like we were in the late 80's on the TZR's. The 125 restriction hype came from those 125's, in Europe they were not restricted and made around 30hp. For the uk the makers just neutered them with basic stuff. Webbing in the carb, exhaust washers, even, longer throttle slides that didn't open as far. You will have to do proper tuning, there is no easy power. That is what people are warning you about. The work you do and the money you spend getting power do the same to a 4 or 600 would get you far more for your buck. That said there is a member on her supercharging and XS tracker because he can. Good luck with it, I took a 600 Suzuki GSXf from 62hp to 95hp as a Q bike, (there was more to come but some stupid bugger got his missus pregnant and the money vanished) lots of fun, a fuckload of money (exhaust was a grand) so go for it. Link to comment Share on other sites More sharing options...
pedroply Posted June 16, 2018 Author Share Posted June 16, 2018 I will try xD thanks for the reply. Didn't knew about those 90mph 125's! I would be happy with 70mph I mean with optimal conditions it could do it even without the arrow exhaust but struggled past 55-60...or even earlier if it was windy! The exhaust really helped on getting to 60mph faster but nothing impressive. I guess the big bore kit will help! Should I be worried about the chinese parts? specially the big bore kit? Link to comment Share on other sites More sharing options...
Moderator Cynic Posted June 16, 2018 Moderator Share Posted June 16, 2018 Mildly but at the end of the day the big bore will only knacker its self and you will have the stock parts to put back. On the 600 I had to have the carbs dynojetted at a tuners, a guy did it by hand. No new jets just used a really fine set of watchmaker like drills in a small hand drill to open airways and jets as needed. The old boy told me before he did it. "You sure son, once this is done these carbs are never going to work on anything else." All I know for certain is it worked. Took 2 days and 28 duno runs and another fuckton of cash. I forget how much but didn't want to tell the wife. 1 Link to comment Share on other sites More sharing options...
pedroply Posted July 12, 2018 Author Share Posted July 12, 2018 Sorry for the long wait for this post. This is the current situation all the parts arrived and today I decided to install them! It was going ok but after switching the cylinder block and mounting the head again the timing sprocket bolt couldn't be torqued to the spec 20 nm without jumping tooth on the sprocket at the other end. Conclusion I mounted it with the rigth timing and torqued the bolt to 10nm. Is this normal? Could the chain be out of the sprocket at the bottom? When I kick the motor it rotates nicely but should I attempt to start it up? Link to comment Share on other sites More sharing options...
slice Posted July 13, 2018 Share Posted July 13, 2018 Well to be honest what else are you going to do? you can if you wish look at it for a couple of days but your still going to have to start it eventually. Best bet, take the plug out and turn it over by hand, if it doesn't hit anything or sound like a bag of spanners then bung the plug back in and start it. Just to be sure have your thumb on the kill switch, you never know it might be perfect. Link to comment Share on other sites More sharing options...
pedroply Posted July 13, 2018 Author Share Posted July 13, 2018 Decided to take it apart again and I m glad I did! After inspecting the bottom sprocket from the cylinder hole I saw the chain was completely out of the sprocket! this probably happen because I m doing all this on the bike normal stand meaning it leans to the left side. It is a pain to maintain the chain in the sprocket so I guess I m gonna put it back together and then try to engage the chain back in the sprocket with the bike leaning right! Link to comment Share on other sites More sharing options...
pedroply Posted July 16, 2018 Author Share Posted July 16, 2018 So today I got the timing chain on and mounted the bike! It started but a noise came up like a tick tack tick tack. It is also smoking a lot. In terms of performance mehh didnt notice any diference so far but hadnt ride it too much either. Any sugestions to what the noise could be? it sounds like coming from the motor head.. Maybe the timing is a little off. It is half a tooth of i think but if I jump a tooth it will be again a half a tooth off in the other direction.. Link to comment Share on other sites More sharing options...
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