RHC Throttle Body Insert Install Help?

[drzadam]

I just got my throttle body insert that makes the 50mm TB into a 43 or something like that. I am thinking it will be a pretty simple install, but it would have been nice to have some instructions. I don't know what all I will need to remove. Will I need to remove the throttle body? I am guessing I'll need to take off the subframe, but is that it? I can see and feel the throttle body velocity horn just inside of the air filter when it is off, so I also thought it may be possible to install the insert from there. It has a hole drilled in it as well as a square ring recess around the middle outside.

Just looking for some help from someone who has put one of these in their 2010 CRF250R, or the 09-10 450R. Any time I can save doing this the right way is great for me.

Thanks,

[drzadam]

no one has installed one of these? Any comments would be great. Ron Hamp? I bet you know what it takes and what to make sure you get aligned. What I am unsure about is the function of the hole and the machined groove around the outside of the insert.

[455]

You don't need to remove the throttle body, just the sub frame to get at the back of the throttle body.

Press the insert into the throttle body by hand, try to line up the hole in the insert with the hole in the TB. There is a grove cut so this is not a must do, but a good idea. The taper of the insert secures it.

Re-install your sub frame (good luck) and ride.

[C64DK]

Let us know what you think of it when you get it installed.

DK

[Ron Hamp]

Thanks 455 for setting him straight when the web sight is going there will eventually be instructions

[drzadam]

Installed Insert today in '10CRF250R.

So far I've just ridden it around on the street. The first thing I noticed is that the response is changed somehow. I'm not sure how to describe it yet, but it feels good although this bike always feels good on the street. Until I get it to the track tomorrow I won't know what real effect the insert has for me. I am pretty sure that it caused the idle speed to increase a few hundred rpms. I don't have a tach but it sounds/feels that way. I'll give an update tomorrow on the track performance.

Here are some pics of the install.

[drzadam]

I rode at the VDR Track near Berthoud, CO today and I was really impressed with the insert. The conditions on the hare scramble track were very dry and hardpacked dirt, and the insert made a nice difference here. The response was very smooth and linear and it also felt like there was more torque available right off idle and in throughout the low-end in general. On the moto track, they had worked it and watered it so it was softer and had more traction, and the insert was great there too. I could be in a situation where I would normally need to downshift, and instead I'd ride it out easily a gear higher with the extra torque that was available. I have a map that Eddie Sisneros made for the bike with FMF Factory 4.1/ Powerbomb/ backfire screen removed, and it seemed to work great with the insert too.

I would recommend it for sure. It is somewhat expensive in my mind it should be able to be made and turn a profit for $50 but what do I know about those things. It cost me $119 + $10 shipping from UFO/Tuf Racing. It was not that big of a deal to remove and replace the subframe as some have complained. The hardest part is getting the boot back on the throttle body with limited space for your hands to work in. I used some vacuum grease on the boot to make it slide on easier and seal better, and I also unbolted the condenser bracket which has some electrical stuff that gets in the way along with the upper chain pulley. Then I got things aligned and left the screw out of the boot clamp, put in the two upper subframe bolts and then worked with the boot to slide it on, and used a magnetic screwdriver to thread the clamp screw into place and tightened it along with the bottom subframe bolts. Not bad really. Took me 10 minutes or so to get the subframe back on.

[Ron Hamp]

the bottom end pull is why there used in the red lizard bikes the guys riding those bikes rarley get down that low in the rpms but they did not hurt the top end and if there was a situation where the red head made a mistake it would help the bike recover sooner the old fart riding the 450 red lizard bikes uses them also.the reason they cost so much is that tuf has to keep bying and throuhing red meat to the old guy with the beard so he can keep his stengh up and continue to desighn cams and gadgets and thing to make your bikes eazyer to ride. they tell me somday that i wont have to be caged and things will be better.

[drzadam]

Ron,

I wasn't trying to knock you or offend you with the comment about the cost. That was the only complaint I had about it. I know it is a precision machined part and so it is not going to be cheap like a cast part. The taper on the outside matched up perfectly and I know that can't be done cheaply. I paid for it and believe it is a nice upgrade for the '10 CRF250R. Have you heard of a company called splitstream? I found them on the net and they sell an insert that is a lot like yours. I imagine the profile on the inside is different, which is what you have said was engineered to improve the flow. They sell them in Europe and I found that Hammerhead sells some of their other inserts but I emailed them and they are not going to keep doing that, so they won't have the insert for the 250R/450R FI bikes. Anyway, the price for this insert is pretty similar to what companies are charging for carb inserts so I can't really complain. Thanks for making a nice, useful product.

[Ron Hamp]

that company is great for copying other pepoles ideas right down to using there pictures and explanations to why they work they had a customer order one i think that was in the netherlands.

[GREAT DANE]

So with all said, for the money its a good mod especially if your running a pipe? Easy install and no remapping needed? sounds gooood. tanks awot

[drzadam]

as i said, i did like the part on my crf250r 2010. it is well made and removable and not too bad to install. for the money, it does some nice things, as discussed. if you have more money to spend, though, i believe that much greater gains can be made with the simon smart body for the crf250r fi bikes. it is supposed to add lots of real power to the entire powerband, and it uses a slide rather than a butterfly valve, similar to a carb. it is an entire replacement for the throttle body, but your sensors and injector are re-used on the slide-type TB. otherwise, check out a similar product to the tb insert from another company, i think maybe athena or someone makes them now too. my vote is for the simon smart body, if money grew on trees... otherwise, insert and some good mapping work by eddie sisneros and of course an exhaust system, and you'll be happy. then just fix the handling! that was the point that caused me to sell my '10 crf250r. could not get the turning to my liking, always dug in and caused me to crash rather than carve a smooth turn. some love it though, just not me. i had 24 mm triples abd they did help, along with a longer link in the rear. i was happier with how my 09 250sxf turned, so it was time for me to sell the honda... i do miss her sometimes.