Sunday, May 15, 2016

TAT-2016 Post 36 - Sunday 15 May 2016

This post is long and probably will be of interest to only those with CRF250Ls since it goes into detail on installing the FMF exhaust system on this bike.

As I stated in my last post (35) I planned on installing an upgrade to my exhaust system this weekend then report on the results after our Memorial Day TAT ride. Sorry but I couldn’t wait to report that this mod is FANTASTIC! I must make the appropriate disclaimer so I don’t offend anyone. All comments below are my impression only and not base on scientific fact.

My 2015 Honda CRF250L is a great bike but stock it isn’t any fire breathing dragon. In fact my first impression riding the bike away from the dealer last Oct 2015 was it is underpowered and definitely did not impress me with its acceleration or even top end speed.

Since then I added the 13t front sprocket, which greatly improved its climbing ability while decreasing the top speed a bit more. Still that was a good mod because it put the 2nd gear exactly in the correct power range to climb most inclines at 18 mph. 1st gear is for only real steep climbs because it is so low the RPM is too high and speed too low for being very useful at any other time.

Leg-1 of our TAT adventure (East coast to AR March 2016) proved my comments above about the 13t mod. Only real issue I had with the CRF on Leg-1 was top speed limitation. I could do 55 mph comfortably and even get to 65 mph if required but the bike was laboring.

I watched numerous YouTube videos on the exhaust upgrade and finally caved in and ordered the complete kit from CRFs Only last week. At $755 this is an expensive modification so I wasn’t real sure if it would be worth the cost but now I can report that it definitely is. I’m sure you could probably get the components a bit cheaper if you shop around or buy them separately but I wanted to make sure they were a matched set so got them all from the same source; CRFs Only.

The kit includes an FMF Q4 Hex Muffler with Megabomb Header plus the EJK Electronic Fuel Control Monitor. The 13t sprocket is an option with the kit but since I had already installed one, this was not required.




The EJK module was delivered separately via USPS and the rest of the kit came via FedEx the following day. As a result, I was concerned that the EJK module had not been preset for the CRF250L so I sent an email to CRFs Only and received an immediate response that it was preset as required. As a side note the customer service at CRFs Only is excellent and I highly recommend them, if you have any kind of CRF.
I couldn’t wait for the weekend to make the modification so I did the complete install on Thursday night.

EJK Electronic Fuel Control Monitor - I began the mod by installing the EJK module under the seat using the supplied Velcro pad. It goes in the area originally reserved for the owner’s manual. Next I removed all the plastic panels on both sides for easy access and visibility plus the seat. The EJK has one long cable with two connectors that go in-line with the CRF harness connector on the fuel injector. The EJK also has a separate ground wire that can go direct to the negative battery terminal or to the common ground bolt on the right side by the fuel tank; I selected the ground bolt. I ran the cable on the left side to just under the fuel tank in the general area for the throttle valve and injector. As much as I tried I could not get my hand or any tool into disconnect the connector on top of the fuel injector. I finally removed the two front bolts and single long rear bolt that attach the fuel tank to the frame. I could then lift up the fuel tank and the throttle valve and injector connector were easily reached. I disconnected the injector connector and replaced it with one of the connectors on the EJK cable and then put the original injector connector into the second connector on the EJK cable. As simple as that. While I had access to this area I put plenty of tie wraps on all of the wire to ensure they would not vibrate against something and possibly wear through the protective cover. I then replaced the fuel tank bolts and finished tie wrapping the cable and ground wires to the frame.

Because I had not started on the exhaust mod yet I started the engine just to see if the EJK would let the engine operate normally which it did. I didn’t want to get the system hot so I shut it down after a short few seconds. I had briefly read the instructions when I opened the box for the muffler and saw that I needed Hi-Temperature Silicon to seal the new FMF exhaust system. I went to Auto-Zone and found just what I needed and returned to start the rest of the modification.

FMF Muffler and Megabomb Header - I removed the old exhaust system including the header pipe in less than 10 minutes. I also removed the heat shield from the old muffler to be reused on the FMF. I had watched a great YouTube on how to do this mod so was pretty familiar with what I needed to accomplish; at least I though I was. This is when I realized just how heavy the original muffler on the CRF really is. It feels like a boat anchor compared to the new FMF muffler. Plus the FMF header pipe is significantly larger in diameter compared to the original header pipe. A lot more air can go through the FMF system for sure.

This is where things didn’t go as smooth. In my haste to get the mod completed and my over confidence I immediately added the red Hi-temp Silicon to the header pipe going into the cylinder head and put it in place. I hand tightened the two nuts holding the header to the cylinder then noticed that the end of the header pipe was on the outside of the frame rather than on the inside where it belonged. I had to undo the two nuts and pull the header out of the cylinder in order to get it inside the frame. Red silicon was getting everywhere and I wasn’t sure I would get a good seal so I removed the header, cleaned off the silicon and started over. The silicon is not easy to remove once applied so have plenty of rags.

Once I had the header installed correctly with the two nuts loosely holding it to the cylinder head, I then put red silicon on the inside of the muffler pipe that slips onto the end of the header pipe. When I tried to slip the muffler onto the end of the header pipe I then realized they were the same diameter and there was no way one would slip over the other! Now I’m really getting irritated. I cleaned off the red silicon from the muffler pipe and tried to figure out why they would be the same diameter since the kit did not come with any type of sleeve or clamp to hold the two together. I decided I needed to read the instructions more thoroughly.

When I unpacked the muffler components there was lots of packing paper in the boxes, which I had just piled in a corner of my garage. I could not find the instructions in this mess. I looked everywhere until I realized I had taken them into the house to read just before I went to get the red silicon; what an idiot. I re-read the instructions slowly and that’s when I saw the comment about removing the sleeve in the muffler if you are also installing the FMF header. As I stated, the original header pipe is smaller than the new FMF header pipe therefore the reason for the sleeve. I used vice-grips to pull out the sleeve, which was not an easy task, then went back to the installation effort.

I once again added red silicon to the inside of the muffler pipe and then slipped it onto the end of the FMF header pipe. These two units are a tight fit so they don’t have to use a clamp to seal the connection so it takes a bit of effort to get them in the right position to match the mounting holds for the muffler bolts.

This is where I need to explain that only part of the original heat shield is reused on the FMF muffler; the white portion. The kit comes with an adapter plate but until I re-read the instructions, I could not figure out how to get the white heat shield, the adapter plate and the FMF muffler into a complete unit. It works but it isn’t obvious. Now the problem was getting the back muffler mounting bolt installed and tighten the whole system up. I used a box end wrench to hold the nut on the back of the muffler and then found that I couldn’t get the wrench off the nut when it was tightened due to it being against the heat shield; crap. I had to loosen everything again and pry out the wrench. I then used an open end wrench and that worked.

The complete kit took me 3 hours to install but if you read this blog and learn the correct way to do the install it could be done in an hour or two max. The kit quality is excellent but the instructions leave lots to figure out on your own. The red silicon instructions said to wait a minimum of 12 hours before starting the engine to let the silicon set. I decided to wait till the next morning to hear how the CRF sounded with its new exhaust system.
BTW I had also planned on doing an air box mod at the same time but I only removed the rubber snorkel out of the top of the air box. That did provide a bit more room for air to get to the engine and I may wait a while before doing more mods in this area.

12 hours later – I got up to go to work the next morning and immediately went to the garage to start the CRF. What a difference in sound. It was definitely louder, especially in an enclosed garage. I felt for exhaust leaks and found none but one thing I did notice as I walked behind the CRF was the strong jet of exhaust gas coming out of the muffler. I never noticed that on the stock muffler so there is definitely a lot more airflow with the FMF.

I was anxious to see how it impacted the performance of the bike so decided to ride the CRF the 12 miles to work on back 2-lane paved roads through some open county farmland.

Performance Review – This review is based on the ride to work and back on Friday and a 50 mile ride I took today on mostly 2 lane paved roads plus a short run on some dirt and gravel roads and trails.

This mod made the CRF250L into a new bike. I can’t start to express the difference in performance but here are few of the highlights:

1 – Acceleration is eye opening. The front end actually feels light and I’m sure I could do a wheelie if I only tried. One interesting thing is that the engine seems to rev much quicker to red line; no tachometer so only going by sound. In fact I never remember reaching a point that the engine felt like it was revving too much with the stock muffler but I do with the FMF. Since 1st gear is pretty low, you shift to 2nd within seconds but there is plenty of power to just keep going through the gears.
2 – Top speed is much higher. On my way to work I reached 70 mph and still had throttle I could use but the bike was feeling squirrely with the knobbies so I didn’t try for max top speed. It definitely has more power at the top end. I could cruise at 60-65 and the engine felt like it was not working hard at all. Even had acceleration if needed to pass even while doing 65 mph.
3 – Sound. The bike sounds tough now compared to the Vespa motor scooter sound the stock CRF made. It is much louder and if you really get on it from a dead stop it can really sound loud. This was something I was concerned about for several reasons including I live in a neighborhood that doesn’t see a lot of loud cars/motorcycles. I quickly realized that as long as I don’t open the throttle wide open I can keep the overall sound down to a reasonable level while in residential and business areas. I still like it though. It didn’t seem to be so loud during normal riding that it would be annoying. Maybe for someone following me but who cares about them, they’re eating my dust anyway.
4 – Street Legal? This is an interesting question. The FMF web site and the paperwork that comes with the FMF components make it clear that these units are NOT street legal, especially in California. I assume because it eliminates the catalytic converter that it no longer meets the federal environmental rules. Something that anyone installing this mod must be willing to accept.

Summary – I already loved the CRF250L but this mod made a VW Bug into a sports car and I like it a bunch. Woodrow doesn’t have this mod so it will be interesting to compare the two CRFs on the Memorial Day TAT ride.













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