BBR Motorsports TTR 150CC BBORE W/CAM BBR Performance 150CC Big Bore Kit With CamTTR125 00-04 - 411-YTR-1201

Kit is actually silver not gold, but that in my opinion is how it should be. I installed it on an 03' TTR-125L, and as far as installation difficulty and time, it isn't hard to do, just pay attention to where you put everything and follow the directions given. Now for performance, there was definitely a difference in power. Keep in mind this was easily recognized on pavement, dirt doesn't reflect it as much (to some people) but even on dirt you can definitely recognize the difference. So some people may not feel a massive difference on dirt unless you have a newer tire and traction is pretty good. However, I paired this with a VM24 carb off of niche cycle, and hands down it completely transformed the bike. I rode my friends 04' TTR-125LE and without a double the low-mid range was a massive difference, and the top end doesn't have that huge 'drop off'. In a straight line, it definitely pulls on the 04'. (Both riders same weight, 04' maybe 10lbs less). Paired with bbr fork springs and rear shock spring, this bike is an adult friendly trail/play bike that hauls on open track.

The kit has pretty much everything you need. You'll need the gasket for the chain tensioner but that's about it. It's really straight forward. We were able to do the swap without removing the motor. It's challenging but can be done. BBR has recommended jet sizes on their website. We're currently running Mikuni 24 carb which is basically the OEM carb size, the BBR pipe and free flow kit. We haven't removed the backfire screen which supposedly adds some power. We're will in the break in period so we haven't really opened up the bike, so we can't speak to extra power or performance yet, but the bike pretty much fired right up. One thing to note is that the timing is easy to get 180 out. We verified the timing by pulling the spark and watching the valves to make sure we were firing on the compression stroke and not the exhaust stroke. Other than that it's all pretty self explanatory. I've heard the BBR might be going out of business which would be a shame. I'm particular happy with the amazon supplier of this kit. I had a shipping question and they were super helpfulOh, btw, the head isn't gold, it's silver which was a little disappointing :)Going to be looking into a similar kit for the XR70Update : We’ve been running the bike through break ins and have been really impressed. The 112.5 main jet for our barn was way too rich. We wound up running a 97 it’s been running great

Definite boot to power, and I still need to fine tune the jetting some more. But I ran into a problem while installing. The holes they tapped into the cylinder to bolt on the cam chain tentioner were terrible. So bad that the treads couldn't even hold under the smallest bit of torque before stripping. And yes, I was using the correct bolts strait off the oem Yamaha cylinder. I even double checked it by trying the next size bigger bolt on the one hole I hadn't stripped, but it was too big for that. And the fun part was I had the new kit installed already before I noticed. Luckily I was able to drill and tap new threads for a bigger bolt. But I had to waste time taking it back apart to fix that. Now I do believe the seller would've helped me had I notified them, but I had to tools and know-how to fix it. So my advice to anyone looking to buy is go ahead and buy it, just check those threads. You should be able to tell by threading a bolt most of the way by hand and try wiggling it to check for play. But now that I got that fixed I'm very happy with the power it has.

The cylinder head is not gold as shown, when we pulled the old cam out the bearing remained in the head, had to take it to shop to have it removed,The kit did give the engine a nice boost

Easy to install (with basic engine building knowledge), all the parts were included, great price (less than $300 shipped), kids havent really ridden the the bike since the install cause its (the big bore kit )part if a christmas gift but i know they will like it.

Easy to install as long as you have a manual to go along with it. Once broken in the smoking stopped and my kid said it had a noticeable power increase. I believed him when he kept spinning out in corners due to lack of traction! I ended up installing a new rear tire and now he's ecstatic with his "new" bike!

Great product, great packaging and it arrived early. Highly recommend!

This kit comes with everything for install except timing tensioner gasket and oil. Easy install and girlfriend is happy with results. Best price I found and it showed up at my house the next day. Also called BBR about jetting and they were friendly and helpful.