Engine Services & Bike Builds

I happened upon Ari's Big Bore Kit website via searching for performance accessories for my 2024 CRF300L. After reading the reviews and about Ari himself and his motorcycle history, I knew that he was the man for the job. I contacted him and we set up a date for me to drop the bike off at his residence. I rode the bike home 2.5 miles from the dealership, loaded it in the bed of my truck and drove from southern Arizona to Long Beach, California to drop it off. I picked it up 3 weeks later and the fun began when I ride if around the trails and mountains here in southern Arizona. The bike performs beautifully and it is an absolutely great bike for off roading all types if terrain. It is the bike I shall use for BDRs and all other off road adventure rides. It hums along perfectly on the asphalt roads at 60 mph to get to the trails and then it really shines. Have ridden it on some very gnarly, steep rocky trails and through sand without worries. Ari knows bikes and is such a knowledgeable and humble guy. It was a pleasure working with him and I am completely satisfied with his products and work. The bike has plenty of power and the suspension upgrades have been spot on! If you have a CRF300, I would highly recommend his big bore kit and suspension upgrades. You will not be disappointed and will have a highly capable dual sport bike that will take you anywhere you want to ride.

In my search for the perfect unicorn ADV bike, I initially reached out to Ari to pick his brain about the 301cc conversion process. While I was still deciding on the right CRF L Rally model, I wanted to get some expert advice. I’m fairly mechanically inclined, but I knew if I were to get a 250L, that splitting the case to replace the crankshaft wasn’t something I wanted to take on for the first time—especially on a bike I needed to be Honda-reliable for off-road adventures.

After discussing my options, I landed a 2018 CRF250L Rally for a decent price. Excited about the build ahead, I pulled the motor and dropped it off along with the throttle body for Ari to work his magic. Throughout the process, the communication was top-notch, and I welcomed his transparency.

An unexpected issue was discovered with one of the cam seats being galled due to a lack of lubrication, so the head had to be replaced. Ari installed the crankshaft, his complete 301 kit, fab'd a spacer to swap in the proper injector for the throttle body, and even modified a velocity stack to fit the specific build. The quality of work was exceptional, as you’d expect from someone with his repertoire in the motorcycle industry.

While the CRF300L Rally offers a lot of upgrades over the CRF250L—such as a lighter frame and larger fuel capacity—if you can find a good deal on a CRF250L and have some budget left for the BBK, I believe this kit really levels the playing field!

Since completing the build, I've added a 1.5ga "camel" style fuel tank, upgraded the suspension front and rear, and made other adjustments to tailor the bike to my needs. I’m currently in the process of breaking in the bike, and all I can say is WOW. Big thanks to Ari and Maverick at 550performance.com for laying the groundwork to make this project possible.

P.S. if anyone was wondering, my initial MPG measured in the high 60's with mixed freeway and dirt riding.

I contacted Ari with questions many times about his big bore kit. I didn't yet own a 300L, but was considering one.

At one point, he mentioned that he had a low mileage, well setup bike coming into the shop and was I interested? Absolutely!

What came out of his shop is nothing short of a BDR unicorn. It could use a touch more power for pulling hills and into headwinds, but this bike is perfect for ADV travel. It's quick and handles very well. It'll plod along desert trails, and rail through the sand, then hop on pavement and get you where you need to go. Ari says his mods don't affect reliability, so I'm hoping for many happy, dirty miles

Part of the build was adjusting the existing Race tech forks and Cogent shock to my needs and it's perfect. This bike absorbs 25# of full travel/camping luggage and floats over woops in the desert like a magic carpet .
Throughout the process, Ari impressed me with his quick replies and respectful dialog. He's a pro through and through and a genuinely nice person that has this platform figured out. He asked to reach out anytime with questions or any help. I believe he'll be there if needed.

I love supporting one man shows doing cool shit. He epitomizes this. Buy with confidence!

After my stock motor locked up on the highway I already new I wanted to go with a CBR300r crank and intake cam. I had also been eyeing Ari's 301 piston to go along with it. After seeing the long track record of reliability and seeing JaketheGardenSnakes videos I knew I was in good hands.

I did not have Ari build my engine since I prefer to learn these things myself, he did however give me tons on help through text. His knowledge of these engines is tip tier and his response time was great.

I, sadly, was one of the very few that had issues with my build though. I believe we narrowed my issues down to improper break-in and using subpar GN-4 oil. The second one I tried to save some money and had a local shop do my cylinder which we later realized was not honed properly and the piston was mishandled resulting in oil consumption and weird surging. Lessons learned.

Even with all this Ari continued to work with me selling me one of his race spares. Since then my bike has been solid. I have not been easy on it either. It has multiple track days and many highway miles on it.

I will also add that I was in contact with maverick of 550performance at the same time and he was also a great help with the build.

I am thankful that we have these amazing people in the motorcycling community and especially ones that love these cheap little bikes like the rest of us.

I have 2 motorcycles that started out as stock 2021 CRF300L Rally's. The first one I purchased new and built it up with Ari's 301cc kit. Right after it was broken in, I left for vacation doing the WY BDR, Red Desert BDR-X, and the Black Hills BDR-X. The bike performed perfectly, great power off-road and on on-road, even fully loaded with a Mosko Moto Reckless 40L setup and full moto camping gear. I was riding with 2 others that had T700's, there was no problems keeping up off road (even leading the way with a lighter and more nimble bike) and on road I wasn't too slow either.

Even before that trip I was talking to Ari regarding the tuning of that engine as I went with a custom tuner in the Dallas TX area. I found out that he was in development of a 316cc kit. I knew I wanted that for my 2nd bike. I have adult son's and wanted them to be able to come with me on some adventures along with my other riding buddies.

I made plans to travel to the Long Beach CA area and have Ari build the engine with the 316cc kit and new head with 2mm oversize intake valves and everything else. I even had a Rekluse TorqDrive clutch pack installed in it. Ari's shop rates were reasonable and competitive. He provided updates as he went though the build and even he was impressed by the rest of the build on the bike. His attention to detail showed in all that he did. He even chased a few threads that were in need of that on the body bolts.
Ari did the proper break-in of the motor as part of his service. And the motor and bike put a smile on his face as he was able to wheelie it from 2nd gear to 4th
I recently did a 200 mile adventure day through the Big Bend area of TX. The run on FM170 was a blast. The ride into BBRSP to the Solitario was a blast. The bike handled the TX desert just fine. Fuel economy was still good as about 67mpg's for that day.
If you look at the total cost to either upgrade the CRF300L Rally to make it into the mythical unicorn do all you want it to versus starting out at a higher price point of a different bike and then spend to make it fully adventure ready, I think the value of upgrading the CRF300L Rally is still a wise choice, and have done so with my money twice