I figured I should leave myself a trail of bread crumbs so I can trace my steps back when things go haywire in the future.
That said, this won't be any crazy build thread, just my rambles as I change things going forward. I bought this quad with a setup I'm quite happy with right out of the gate but I'd like to tinker and try to improve it as I go.
When I bought it it had a full HMF exhaust and the lid removed. It had a janky filter setup with the stock filter and a "custom" bracket to hold it in. Up front it has a set of 2in spacers and Hydro-Dynamic Ishock i5500's which should probably be rebuilt due to age but still ride great and show little wear. Out back it has a tusk adjustable axle. It has AC nerfs and Propegs (love these) and is otherwise stock to my knowledge.
The first thing I did was install a Uni clamp-on filter using the MAP-sensor adapter method. I also found the petcock to have failed and installed a 660 petcock and a pull choke. The pull choke ended up being the wrong type (no taper on the end) and had me scratching my head for a few days.
After installing the correct type of pull choke it ran far better but still seemed like it didn't like idling consistently and seemed twitchy at low throttle cruising.
Being that I live in the frozen wasteland of northern Minnesota and it ran great above 1/8 throttle, I ignored the small annoyances and made the most of the fleeting warm, end of summer weather. I did a blob delete, reverse/key relocation with a 3d printed key mount I designed, installed ODI Rouge grips and checked the valves. I painted the valve cover while I was at it, red makes it faster right? The valves, to my surprise, were spot on in the middle of the spec. I should check them again soon but I was happy to see they seemingly survived the aforementioned janky filter from the previous owner.
I did some local TT style racing and had a blast in the early fall as well.
In December I worked out that the air cut off valve was missing it's spring, this was the cause of my idle and low throttle cruising issues. I blocked off the vacuum signal for it and put a random spring I had in it, now it runs beautifully, go figure.
January saw a fair bit of ice riding and the death of the stock grab bar from a few wheelies that went too far back. I bought a tusk one, absolute garbage, first time it hit the ice it bent. I decided I needed a stronger one to handle my inexperienced wheelies so I made a stainless steel one that so far has held up great, it even excavated the frozen ground without any damage and is still pretty light. I also found some cracks on the stock swing arm, welded them up and decided to start collecting parts to do a LTR swinger swap.
After riding my buddies YFZ450 I understood what people meant by how snappy the FCR carb was.
Now it's February and I have a 03 crf450 FCR 39, a set of jets for it, an extended fuel screw, a 400ex boot in the mail, a set of ninja 500 carb to head boots in the mail as well as a trx450 throttle cable and 400ex thumber. I'm also waiting on a mid body gaskets sets, I figured if I ignore the gaskets it may lead to chasing my tail while jetting if they are bad. I also intend to 3d print an adapter for the carb intake out of nylon, I think it should handle the heat and fuel vapor just fine and have a design ready to go, just gotta make sure it fits with the 400ex boot.
As for the LTR swing arm I'm going to continue to slowly collect parts for it, I'm not super concerned about the stocker for now since it's welded, but I'd like to get the swap done sooner then later. I also plan to modify the LTR sprocket mount by lathing down the outboard side and adding metal to the seal/bearing side to correct the chain mis-alignment that I had seen on some posts on Facebook. I'll also need to modify the chain guides but that's the least of my worries.
Aside from the FCR and swing arm the next mod I'd like to tackle is YFZ450 front calipers, braided lines and fresh fluid. After that I'm eyeballing Alba's +3 A Arms so I can ditch the spacers and hopefully reduce bump steer in doing so.
Anyway I should probably get back to work, I intend to update this as I get on with the FCR swap. If your still reading at this point I appreciate you dropping by to read my rambles!