Free CRF300L exaust mods, weight reduction and a tune!

[@kevinmcbride8446]

If you're gonna drill holes in the spark arrestor you might as well just cut I off completely, that's what I did and it sounds really good.

[@ronald8673]

HP gains come from burning more fuel, bigger explosions = less mpg. Is the cat a self contained unit ? I have a repl. ss header/alum exhaust muffler on order but might try to put the cat back in some how. Most weight comes from mild steel full frame, steel exhaust, steel handlebars, steel gas tank, steel rear sprocket, steel foot pegs, steel head lite/gauge support, steel mirror rods and emissions hardware. All other normal bike bits are alum. or required steel like brake discs, chain etc. Thanks for posting.

[@ChuckHolt]

Yep

[@WanderingDad]

Drilled the spark arrestor on mine. Tested using my Dynojet, it was faster 4k to 10k in 4th (only gear I tested), injector duty cycle was higher, but I got better mpg. Better flow= better efficiency, but I'm very slow so no ripping around for me.

[@ChuckHolt]

That’s awesome that you got actual data from it!

[@cdwyer8295]

Unfortunately not at all possible on our European models produced after 2022, they are all welded in…. so, the only possibility is a completely new exhaust system 🤔

[@ChuckHolt]

The US model is welded in as well, just gotta get creative.

[@dailylife3975]

The reason why it runs hotter on your leg is because they run lean from the factory so when you do the ECU it richen it up a little bit

[@ChuckHolt]

Absolutely, but the heat from the cat doesn’t help things, we did the same thing to another bike and it dropped the temperature of the exhaust pipe by your leg 36 degrees when measured with a temp gun, and that bike did not have the 550 performance ecu at that time.

[@phantomshtter]

No. It's the cat and the stolen airbox air that's run to the pipe to literally increase exhaust temp my dude.

[@user-se7vt5ow4e]

@@phantomshtterExactly. The simplest fix is just plug the hose from the air box to the pair valve. It will also stop the popping sound coming from the pair valve. Also wrapping the exhaust keeps the heat off your leg.

[@MrBlaze256]

On the road a windshield would make a difference. somehow I hit 90 on my 250l the other day

[@MotorcyclesOffroad]

Removing the cat and drilling those holes will make the bike more hot on your leg. The whole reason it feels hot is because the bike runs super lean from the factory. When I got my ECU flashed to stage one from 550 performance, it took all the heat away. Did you feel the same from the ecu? also fyi You loose mpg with the ECU because the flash advanced your timing.

[@Luckyluke141]

I would imagine removing cat will help cool temps down because in order for a catalytic converter to work in needs to get extremely hot to change change the harmful compounds in the exhaust to safer ones. Of course a lean motor will not help with heat but throw a cat on top of that and now we’re talking a lot of heat.

[@Luckyluke141]

Also love your videos as well! Keep on keeping on!

[@MotorcyclesOffroad]

@@Luckyluke141 thank you!

[@ChuckHolt]

The mileage loss comes from the enrichment of the fuel map, the timing just adds performance based on the fact that you will only be running 91 octane. I understand the fuel enrichment is a direct trade, power for mileage, I just figured people should know what they are getting into when doing the ecu, the fact that it’s running richer makes EGTs cooler obviously, but the cat area was 60ish degrees hotter than the muffler directly after the Cat according to my temp gun, plus I figured it couldn’t hurt getting it to breathe better.

[@MrBlaze256]

The cat has to glow red hot to burn the leftover fuel. So removing it would help cool that area

[@ridelikekrum7707]

Insted of drilling small holes in the arrestor i drilled it and removed all the blocking plate and reinstalled. sounds just right for me and I picked up 6 mpg. I now avg 80.1 mpg

[@ChuckHolt]

Wow really? Nicely done

[@ridelikekrum7707]

@@ChuckHolt yep thats the only thing I changed on my 300. just by opening up the exhaust went from 74 mpg to 80+. It also gave it a little more bottom end.

[@damacknificent151]

Would be nice if you did a video for us beginner's. How you did it step by step.

[@OmarLopezAguirre]

Hi buddy! Do you have to modify anything else or just drilling the holes is enough? I just want to know if this procedure will not damage my bike ! Thank you !

[@ridelikekrum7707]

@@OmarLopezAguirre it will not hurt anything. So all you do is remove he cover on the muffler. Then remover the three bolts holding in the exhaust tip. When you remove that you will see the blocking plate inside the end of the tube. That is what i drilled out to have no restriction with the air flow.

[@Scoottoots]

Nice. You didn't mention (I think) which ECU you installed. Was it the stock improved 87 octane, Stock improved 91 octane, or one of the stage one versions. I have the stock improved 87 octane and it has improved performance noticeably. Btw, if you're in a fire-prone area, you no longer have a functional spark arrestor with the holes drilled in the end cap. I live in a high risk wildfire area so I just drilled out that end plate completely and covered the hole with spark arrestor screen. I imagine removing the CAT did the most in freeing up the flow. Good stuff :-)

[@ChuckHolt]

I am running stock improved 91 octane, I thought about drilling bigger holes and covering it with screen, still might

[@joeheiser4126]

How did you take the catalytic converter out of your pipe? Do you have a video of that?

[@ChuckHolt]

With a long 1/2” drill bit and a big bar and hammer

[@gosolobox]

Looks like a Walker Valley Trials rear tire..

[@ChuckHolt]

Motoz mountain hybrid

[@olav2449]

Anecdotal tuning by sound.

[@airadaimagery692]

How much is an ECU, and what is the block off plate for?

[@ChuckHolt]

550 performance tuned ecu is $150 if I remember correctly. The block off plate blocks the port for the exhaust recirculating circuit, so I could get rid of all the emissions crap.

[@mt1885]

I got the smart moto kit for the other items and will do the 550 should get bike in Jan 2023 sometime. But wanted to get rid of that and the exhaust. Can you post a link to the pair deal and is the 550 ecu no check engine light after right?

[@ChuckHolt]

Correct, no check engine light with the 550 ecu, I will see if I can find the pair block off again, it was on eBay

[@ChuckHolt]

I cannot find the pair valve block off plate anywhere for sale.

[@mt1885]

@@ChuckHolt I think found it smart moto

[@marcochavanne]

Can I get a link for the plate? Google didnt pull anything up for that part number

[@ChuckHolt]

www.ebay.com/itm/224661589971?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Sa_qteMJQ0S&sssrc=2349624&ssuid=w3YPOWoPS46&var=&widget_ver=artemis&media=COPY

[@waynekelly9395]

So is this all stuff that can be pulled out and unbolted or did you have to do some major hacking

[@ChuckHolt]

It was pretty easy, but definitely not reversible, getting rid of the cat was a little time consuming, modding the spark arrester plug was quick and easy.

[@dirtbiketommy1144]

What's ur mpg now?

[@ChuckHolt]

Over the last 2 tanks since this stuff was done it was 68.9, this was about 20% trail 40% gravel road and 40% pavement.

[@dirtbiketommy1144]

@@ChuckHolt that's awesome I'm getting about 62 minus one tooth in the front and mainly riding around town

[@t_c5266]

What was the total weight saving and cost of all this?

[@ChuckHolt]

I only had access to the race scales once I was done, so I wasn’t able to weigh it before, I do know it ended up at 311 with everything I added, obviously I took as much as I could off, but in my opinion a bike isn’t ready for Rocky pnw single track without a good skid plate, hand guards, and a rack for extra fuel, beer or occasionally overnight supplies. So with all that it only gained a couple pounds. As far as cost, I didn’t add it all up, a lot of it I bought way before the bike even showed up and I don’t remember.

[@t_c5266]

@@ChuckHolt ahh for sure. Thanks! And I can't believe the bikes don't come with a skid plate. I have one and bought a skid plate asap. Went riding this weekend and kicked a huge rock up. It dented my skid plate and actually gouged it a little. That would have put a hole straight through the case. Also idk if I saw it or if you mentioned it. But might as well toss the 2nd rider pegs on the back lol. Useless weight unless you're always taking someone somewhere

[@ChuckHolt]

@@t_c5266 yep, I tossed them, the reflectors, the giant rear mud flap thing, the upper chain cover, the weighted bar ends, one mirror and the emissions crap

[@aldearadu5219]

how did u get the cat out ???

[@ChuckHolt]

I used a 12” long 1/2” drill bit and a steel spike and just kept drilling and pounding and prying until I got everything out, I didn’t want to show that part on video for obvious reasons

[@Eddie_Turbo]

Is it simple to remove the cat? or do you need to grind/reweld the exhaust back on?

[@ChuckHolt]

no, its pretty easy, i used a pry bar and and a hammer.

[@jimmeyer4822]

@@ChuckHolt I want to see that video!

[@jimmeyer4822]

@@ChuckHolt please tell us more! No video of that??

[@ChuckHolt]

@@jimmeyer4822I would’ve but video of that would get me in hot water

[@basilistitieh5862]

what skid plate is that?

[@ChuckHolt]

Acerbis for the 250L fits perfect, all you have to do is drill 2 holes in it at the front

[@phantomshtter]

Bunch of butt dyno bologna. The 550 ECU doesn't improve felt performance. Gutting the stock exhaust definitely doesn't. If you felt any increase at all I would say it would be from the weight loss and your itchy throttle palm post mod.

[@ChuckHolt]

Gutting the exhaust wasn’t aimed at gaining performance, it was done to keep the leg heat down, and it didn’t that by a lot. As for the 550 ecu it was literally night and day difference, in fact we rode my 300l with the 550 ecu and my brother in laws back to back and we both noticed a huge improvement. And judging by how lean it was from the factory I don’t see how it couldn’t be, peak performance isn’t at 15.6:1.