Jump to content

Day 4: Test and Tune (CO jetting tips)

AUbraaap

158 views

You wouldn't believe the excitement I woke up with on the first day we woke up in CO. I laid there for a moment to check my phone and call my Dad to tell him we had made it without trial. I got up and threw some clothes on and quickly went up the stairs. At the top of the stairs I experienced something that I've never felt in my short 25 years, shortness of breath from a flight of stairs. Steamboat Springs, CO sits at about 6,700 feet of elevation. I just drove here in a couple days from sea level and there was no time for my body to adjust. The rest of the day and some of the week I would be plagued with this problem over and over. Anyhow, I made my coffee and had a bite to eat while everyone else rolled out of bed and got ready to start the day. 

This day was all about prep for the week. We had to move trailers around and stuff 8 bikes into one trailer and a hitch rack. The apartment complex was not keen on us wrenching right there in the parking lot and we got a complaint the very first day. Some people just don't want you to have any fun. We had already made the decision not to start a bike there and we never did, but what can you do? I digress. We managed to get everything loaded up into the trailer and another truck and headed up a mountain range to go jet and get warmed up for the week to come. 

The destination was just outside of town, I know, crazy, a mountain just outside of town. We went halfway up Buffalo Pass to a parking area where we had plenty of room and freedom to test and tune the bikes. At this point we are up to about 8,000 feet and the thin air is killing me. I stood up from squatting to put on a skid plate and nearly passed out. The first bike I get on is my 450 SX-F. I was thinking the fuel injection would just pick right up and be great. WRONG! It would not lug around at all and wouldn't rev out for about 20 minutes until it adjusted to the atmosphere. Once it got running correctly I was well on my way to annoying all the mountain bikers with my loud FMF exhaust and power wheelies through the parking lot. after a little play time the real work began. We had 5 carbureted bikes to jet. Luckily Austin already had a baseline with his 2012 300 that he had been riding out there for several months. I started with my 300, a 2012 model as well. I went form a 38 pilot from Florida to a 42 pilot to get the 1/4 throttle spot good. That has to be the most counter-intuitive jetting situation I've ever encountered. Less oxygen + more fuel + less air pressure/vacuum = a very crisp throttle crack at 8000 feet of elevation. Then on the main i went from the 162 I run in Florida summer to a 158 because at that point the air pressure doesn't matter and the engine is just sucking well enough on its own. After a little air screw adjustment the bike ran better than it does at sea level; I attribute this to the lack of humidity and heat. 

The jetting trend continued for the other 2 stroke bikes, all but one was a KTM. The 1994 Honda CR250R didn't need the same amount of adjustment. The pilot in it was fine but it needed a little less fuel at WOT. I couldn't tell you what we did to the 250 four stroke that we had. I just know that no matter what jets were in it, it was a dog. Don't take a 2008 KTM 250f to Colorado. You won't be impressed. We also had a 2009 KTM 250 smoker that we couldn't quite figure out, that bike gave us fits for a couple of days actually. The five of us that were there geared up and hopped on the bikes to head the rest of the way up the mountain.

We got out on the county road, dirt and baby heads, that continued Buffalo Pass up to the continental divide trail. I started on my 450 and Chase was on my 300 because Chase doesn't currently own a dirt bike but wanted to come along and the 300 isn't quite as overwhelming to start on as a 450 can be. I would never recommend letting an inexperienced rider borrow your bike for a week, or anyone really, but in this case Chase is a professional down hill mountain biker and knows his way around 2 wheels. That 450 was a blast heading up the pass. You could just let it eat as long as you avoid the big rocks and holes in the road. It was about 5 miles of winding road to the top and let me tell you I have never seen such a great view before. I immediately got nostalgic. This isn't something just anyone gets to do, or has the opportunity to do. I recognize the moment for what it means to me. At the top we start on the continental divide trail and head south. The section of trail we were on started very flowy. It would dip into woods and then pop you out in a field and dip back in. Then you'd slow up for a rocky section and nail the throttle again. It had just rained an hour before and the soil was perfect up there. Everything just stuck. I couldn't believe how well the trail section flowed and how much fun it was, but I've also been riding in Florida for a year at this point with nothing but sand trails and whoops. That first day I just kept getting caught up in the beauty of my surroundings and a surreal feeling that I was actually there riding some of the best terrain in the country. 

We came to a pond ad stopped for a break and to talk about how the bikes were doing and how much arm pump we all had. At this point we are about 10 miles in and the CR250 has already lost the rear brake lever from impact with a rock and would remain broken all week. Josh was not ready for Colorado. His bike wasn't ready and the week just got tougher. I let some air out of the forks on my bike to soften it up a little but was surprised at how well the front was taking the rocks. The rear wasn't but I couldn't do much about that. Patrick's 2009 250xc was down on power a lot and my 300 was running excellent. I have no doubt the slavens head mod helped it a ton out there. 

We turned back to get back to the truck before it got too late so we could get home and meet the other 3 guys that would be arriving that evening. The trail ride back was slower because we stopped to check out the scenery and different features and to wait on the 2 slower riders. Austin found a massive tree that had fallen and had to ride over it. The top of the trunk was about 3.5 to 4 feet off the ground at its base, he managed to get over it 3 times. I didn't have the balls to try it the first day and risk breaking my arm. Then he proceeded to ride up the trunk and launch off the root ball. I did try this but I don't have the balance yet to ride up a tree trunk like that. I'll add video below if I can find it. 

If you've never ridden on trails that also have hikers I would suggest being as respectful as possible. Always slow down and crawl past them. Every hiker we encountered did get off the trail for us and we slowed down to idle past but most were VERY upset to see us. One or two were friendly and cheered us on but that was not usually the case. We got yelled at with several profanities and middle fingers. You can only do so much to make people happy but those measures should be taken even if their reaction is negative. 

We made it back to the truck and loaded up to go back to the apartment uneventfully. The last 3 riders showed up late that evening. Beers were had, pleasantries exchanged and off to bed to rest up for the day ahead. I would definitely like to ride more of the divide trail in the future. I had an absolute blast on it. It is mostly double track in the area around Steamboat but has many single track off shoots to explore. 

IMG_0989.jpg

IMG_2395.JPG

IMG_2397.JPG

  • Like 1


0 Comments


Recommended Comments

There are no comments to display.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

×