LTR/CRF Hybrid build

[patrickj75]

I'm going to build an LTR/CRF hybrid for the 2013 season. Using an 06 CRF bottom end, Cylinder Works 450 cylinder and 08 CRF head. Hoping to use a TRX ehaust so it runs out the right side. Then I should be able to run a big filter setup. Leaving my chasis pretty much the same from the 2012 season.

Here's my LTR from this season.

[honda250xrider]

You can run a trx exhaust; you will have to trim your rear plastic for it to fit though.

I am currently running a walsh intake with a larger K&N filter

[patrickj75]

Originally posted by honda250xrider
You can run a trx exhaust; you will have to trim your rear plastic for it to fit though.

I am currently running a walsh intake with a larger K&N filter

Yea, I figured I will need to trim a little plastic. What intake boot are you running to the carb from the filter?

[quadcrazy02]

gona be sweet!!!

[honda250xrider]

I am using a silicone 45 degree tube that is 2 1/4 I believe to 3" then I use a 3" alum. 45 degree intake tube attached to the walsh intake. I tried JB weld as I didnt have a tig welder handy and the JB weld did not hold. If you do it this way I would recommend you have it Tig welded.


Once the 3" intake tube is welded into the walsh intake I took a dremel to the intake tube and used JB to make a seamless transition.

[KBooth]

A friend of mine is just finishing his ltr/crf hybrid, seems to be a pretty easy build.

[patrickj75]

Originally posted by KBooth
A friend of mine is just finishing his ltr/crf hybrid, seems to be a pretty easy build.

You should have him post some pics. I'd like to see what he did with his build.

[KBooth]

Larger

[KBooth]

Pic

[KBooth]

Pic2

[hontrx265r]

Looks good one concern I have with the honda in the suzuki frame is how much higher the center of gravity is compared to the ltr motor. It will obviously work but I think its a compromise in handling that suzuki engineered very well in the begininning keeping the crank low and using the external oil tank. Just something to think about since u race t.t

[polaris33563]

I spent time thinking how low I wanted the motor in this ltr crf. Its only about 1/2 of a inch higher then the ltr motor. I think the crf motor is the way to go. The motor fits in there perfect. The pipe was super easy to fit. Just bent the head pipe alittle and tig welded the honda exhaust mount that bolts to the head. The crf motor is a ton lighter then ltr motor can run the carb (ltr efi blows) big air intake, kicker, I think there is a ton of pros then cons in doing the motor swap.

[Groves187]

The intake length and filter size is crazy, I have a 04 crf450 Lsr hybrid and we have done a lot of intake testing on the dyno. A bigger filter isn't always a good thing as it could throw off your intake velocity. If you looked at the intake length and filter size we ended up with on my hybrid you would be really surprised it makes the power it does.

[polaris33563]

I used a 3 inch hose and a trx 450 air filter. I didnt use a bigger one. The more u can get a big bored motor the better off you are.

[R3Concepts]

Patrick look into a 06+ TRX head. Much better head in my opinion.

[patrickj75]

Originally posted by R3Concepts
Patrick look into a 06+ TRX head. Much better head in my opinion.

Bought an '08 CRF head already.

[polaris33563]

That's what I used a 06+trx head a lot easier to find one already modded.

[patrickj75]

Update: I have most of the parts I need for the motor. Just need to order a cam, valves and valve spring kit. I'll ge using a Yoshimura stainless exhuast.

[patrickj75]

I have the Yoshimura TRX exhuast. I should be sending out my head and tranny gears to Factory 126 this week for a little more horsepower. After that I'll get the motor assembled and ready for the frame installation.

[patrickj75]

Full Hinson clutch is ordered. Shipped my head and tranny gears off to Factory 126 today. Was able to sell my -1 Walsh swingarm and get a Roberts -2 swingarm.

[ZRider400]

Post some update pics :-)

[patrickj75]

There's nothing really exciting to post for pics. Just boxes of parts right now. I'm still trying to figure out colors for powdercoat.

[patrickj75]

Here's the carbon fiber tank cover and shrouds from Fourwerx they just finished for me.

[patrickj75]

CF shrouds....

[patrickj75]

Hinson clutch showed up yesterday. Also got a pair of the Precision shock and vibe clamps for my stem.

[honda250xrider]

If you have any questions when building it let me know. I made one a couple months ago. The only thing I will suggest is making a tab for the on/off fuel switch. I used the crf on/off valve and welded a tab to the frame right where you have your coil.

I mounted the coil on the front frame rail angled downward which gave me enough room to still use the stock spark plug wire.

I used a side mount exhaust with walsh's large intake. By doing this I was able to use a larger filter than normal; before this, the pipe was getting so hot that it was melting the K&N filter.

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[honda250xrider]

One thing to note; you may or may not have a problem with the rear shock rezzi. I had to relocate mine to the front. Because of the intake location the line had to be kinked a bit to fit with the rear clamp. I tried this method and busted the line on the first jump. If you had the center mount exhaust you could just go over to the right side; with the side mount my only choice was to get an extended line and mount it up front.

[patrickj75]

[QUOTE]Originally posted by honda250xrider
[B]If you have any questions when building it let me know. I made one a couple months ago. The only thing I will suggest is making a tab for the on/off fuel switch. I used the crf on/off valve and welded a tab to the frame right where you have your coil.

I mounted the coil on the front frame rail angled downward which gave me enough room to still use the stock spark plug wire.

I used a side mount exhaust with walsh's large intake. By doing this I was able to use a larger filter than normal; before this, the pipe was getting so hot that it was melting the K&N filter.

My LTR had a carb on it so my tank etc is already setup with an on/off petcock.

I'm going to run an 04/05 TRX intake with a DASA filter/ring. Probably a similar setup to what you have.

What did you do to align the sprockets?

[patrickj75]

Originally posted by honda250xrider
One thing to note; you may or may not have a problem with the rear shock rezzi. I had to relocate mine to the front. Because of the intake location the line had to be kinked a bit to fit with the rear clamp. I tried this method and busted the line on the first jump. If you had the center mount exhaust you could just go over to the right side; with the side mount my only choice was to get an extended line and mount it up front.

I'm running a PEP rear shock with the rezzy on the grab bar. I'll check that out when I get the intake setup mounted in there. I race TT.

[honda250xrider]

I did the easiest method IMO. I had the swing-arm cut down I believe a 1/4" or so. That allowed the engine to move over far enough so the sprockets aligned. Then I made up a sleeve for extra space on the right side and put in seals. If you already have the motor mounts made this may not be an option now.

I did not want to have to have a custom sprocket made; the reason being is replacement sprockets are cheap and are available just about everywhere.

You could always take it from the axle and mill down the bearing carrier and sprocket hub. I believe I did the measurements and you would have just enough room to get it to work without having the sprocket bolts hitting the bearing carrier. (of course this is on mine, I am using a 07 crf motor)

[patrickj75]

Originally posted by honda250xrider
I did the easiest method IMO. I had the swing-arm cut down I believe a 1/4" or so. That allowed the engine to move over far enough so the sprockets aligned. Then I made up a sleeve for extra space on the right side and put in seals. If you already have the motor mounts made this may not be an option now.

I did not want to have to have a custom sprocket made; the reason being is replacement sprockets are cheap and are available just about everywhere.

You could always take it from the axle and mill down the bearing carrier and sprocket hub. I believe I did the measurements and you would have just enough room to get it to work without having the sprocket bolts hitting the bearing carrier. (of course this is on mine, I am using a 07 crf motor)

We haven't done any frame fab work yet. I'm building the motor first then fit it in the frame. What did you do for motor mounts? My motor is a combination of 05, 06 and 08.

[honda250xrider]

I'm assuming the 06 crf motor allows you to clear the rear shock tower. (I tried the 04/05 trx intake) On the 07 crf I had to use a 05 crf 250 intake boot. (its angled) Then I used a 2 1/4"- 3" silicone 45 degree tubing to make the bend. I then used a 45 degree alum. intake piece and tig welded it to the walsh intake. I then brazed the inside of the intake to the alum piece and used a dremel to create a seemless transition.

Hopefully the picture explains it better than my words.

*this is with a 41mm carb and before I had angled braces welded in.

[honda250xrider]

. this is what it looks like

[patrickj75]

Originally posted by honda250xrider
I'm assuming the 06 crf motor allows you to clear the rear shock tower. On the 07 crf I had to use a 05 crf 250 intake boot. (its angled) Then I used a 2 1/4"- 3" silicone 45 degree tubing to make the bend. I then used a 45 degree alum. intake piece and tig welded it to the walsh intake.

Hopefully the picture explains it better than my words.

*this is with a 41mm carb and before I had angled braces welded in.

I'm running an 08 head. The tranny is 06, the cases are 05 and 06.

Looks like you changed your upper shock mount so it runs straight across? I'm planing on doing that with mine. The TRX intake tube looks like what your setup is so I'm hoping it will clear once I lower the shock mount.

[honda250xrider]

for the motor mounts I simply just used a piece of poster board and made a sketch and kept cutting it to the right shape. From there its just a matter of converting it over to steel.

I did have to make the right motor mount offset. The left front motor mount is literally a straight shot. (in my case)

[honda250xrider]

Originally posted by patrickj75
I'm running an 08 head. The tranny is 06, the cases are 05 and 06.

Looks like you changed your upper shock mount so it runs straight across? I'm planing on doing that with mine. The TRX intake tube looks like what your setup is so I'm hoping it will clear once I lower the shock mount.

Yes it does run straight across; although I did add braces to the bottom left and then to the upper right. (not seen in photo). I need to get some current pics; unfortunately I didn't take very many photos of the build and which can make it hard for others to see the transition piece by piece.

[patrickj75]

Originally posted by honda250xrider
Yes it does run straight across; although I did add braces to the bottom left and then to the upper right. (not seen in photo). I need to get some current pics; unfortunately I didn't take very many photos of the build and which can make it hard for others to see the transition piece by piece.

There was a guy in France I believe that did the same build and posted detailed pics. I saved them to my computer so I have a good idea of what needs to be done. I have a friend who works at a machine shop so he's going to do the fab work for me.

[TuckerHardRide]

Patrick post some more pictures!

[patrickj75]

Originally posted by TuckerHardRide
Patrick post some more pictures! I will when something happens. Right now I'm waiting on my motor then once that's togeth we'll do the work on the frame.

[TuckerHardRide]

Any ETA on the motor?

[patrickj75]

Originally posted by TuckerHardRide
Any ETA on the motor?

Couple weeks maybe.

[honda250xrider]

Just wanted to comment. I was able to weigh the bike the other day and its aprox. 375 with full tank of gas. I could lose another 20lbs pretty easy if i went with an aftermarket axle, hubs, subframe, swingarm, and some 2ply tires. I am using 6ply dunlop tires which are pretty heavy. I think it's realistic to expect right around 350lbs if you had everything aftermarket. I choose to keep the stock axle and swingarm because of the strength and cheap replacement costs for racing. You can find good used swingarms and axles for little to nothing on eBay

[patrickj75]

Originally posted by honda250xrider
Just wanted to comment. I was able to weigh the bike the other day and its aprox. 375 with full tank of gas. I could lose another 20lbs pretty easy if i went with an aftermarket axle, hubs, subframe, swingarm, and some 2ply tires. I am using 6ply dunlop tires which are pretty heavy. I think it's realistic to expect right around 350lbs if you had everything aftermarket. I choose to keep the stock axle and swingarm because of the strength and cheap replacement costs for racing. You can find good used swingarms and axles for little to nothing on eBay

My quad is set up for TT so I'm hoping for around 330lbs. It was 366 without fuel when I had the LTR motor in it. I have lightweight a-arms, swingarm and subframe. I don't have any Ti on it but that could change this year. All my hubs, carrier and axle are Lonestar.

[honda250xrider]

I would say you should be close. As you will drop around 30lbs with the motor maybe a bit more. I never weighed the crf motor or the ltr motor so that is pure guessing.

[patrickj75]

Originally posted by honda250xrider
I would say you should be close. As you will drop around 30lbs with the motor maybe a bit more. I never weighed the crf motor or the ltr motor so that is pure guessing.

My LTR motor with oil tank and no fluids was about 80lbs. I'll weigh my CRF when it gets put together.

[hontrx265r]

I think your loosing maybe 15lbs at most the newer crf is 56lbs I know the older ones were heavier. My yzf was 68.

[honda250xrider]

You bring up a good point I will weigh the crf motor today and see what it reads. I am using a 07-08 motor

[polaris33563]

I used a 04 crf motot 58 pounds

[honda250xrider]

just weighed the 07 motor: 57.60lbs

[honda250xrider]

you could figure about losing 22lbs;

I'm not sure if you had your harness gutted; but you would probably lose another lb or two from not having to run all the wiring and electronic components. realisticaly you are probably looking at 25lbs savings as long as you do not add any weight when making the new brackets for the motor mounts etc

[patrickj75]

Originally posted by honda250xrider
you could figure about losing 22lbs;

I'm not sure if you had your harness gutted; but you would probably lose another lb or two from not having to run all the wiring and electronic components. realisticaly you are probably looking at 25lbs savings as long as you do not add any weight when making the new brackets for the motor mounts etc

My LTR was a carb/kick start.

[patrickj75]

I just got my head and tranny parts back from Factory 126 yesterday. Hoping to start putting the motor back together in a week or so.

[honda250xrider]

looking forward to seeing the motor come together.

[honda250xrider]

any updates to the build?

[patrickj75]

Got the motor back together. Brought the quad down to Rath Racing to have them make the motor mounts, bumper, nerfs and grab bar.

[patrickj75]

New upper rear shock mount done.

[yfzttracer76]

Are you going to any tt nationals this year?

[patrickj75]

Are you going to any tt nationals this year?

I'm hoping to make Sioux Falls but I'm not sure when this build will be done. How about you?

[patrickj75]

Front motor mounts done.

[patrickj75]

Motor is all mounted in.

[TuckerHardRide]

How is the kicker working out for you, what are you using for it?

[patrickj75]

How is the kicker working out for you, what are you using for it?

They had to take a small piece out of the frame for clearance. It's a 99-01 YZ250 kick lever.

[yfzttracer76]

I'm hoping to make Sioux Falls but I'm not sure when this build will be done. How about you?

hoping to make batavia and ashtabula

[patrickj75]

hoping to make batavia and ashtabula

I'm thinking of just doing District 23 this year and get all the bugs worked out for next year.

[yfzttracer76]

Thats cool, I saw rath is doing a tt school seems like an awesome idea.

[patrickj75]

Thats cool, I saw rath is doing a tt school seems like an awesome idea.

Yea, he just did one in May. I'm signed up for the one in July. He might do one in August.

[patrickj75]

Honda TRX exhaust mounted. We're getting closer....

[patrickj75]

Got the quad back from Rath Racing last week. Here are some close-up pics of some of the things they did.

[patrickj75]

Graphics kit for my hybrid.

[2001400exrida]

Looks like the hybrid is coming along nice. I've heard Daryls school is very worth it. That guy certainly knows his stuff if it wasn't so far away i'd consider going!

[patrickj75]

Looks like the hybrid is coming along nice. I've heard Daryls school is very worth it. That guy certainly knows his stuff if it wasn't so far away i'd consider going! Yea, it's getting there. Just a few little things to finish up.

Daryl's school was definitely worth it. Lots of good info.