Why CRF450 valves need adjustments and how to do the math

[1999chegado]

can you help me out

i have ttr230 wont idle and has to be choked to run..

i clean

the carb any idea and new gas

its hard to start

[mtbjuky]

going to put two newe exhaust valves in my crf 450, do i need to take the head out to a machinist to be seated?

[briansmobile1]

@mtbjuky It helps, but isn't mandatory for good performance.

[allencathcart]

this is good to know but im not going to do any of this on my 06 crf450r ill have the guys at honda do it ill get a broken bike and fix it and then sell it so i learn and dont mess up my good stuff

[mwd92]

could you make a vid of ur shop and how to start a business from home plz

[briansmobile1]

@mwd92 When I get it how I like it I may. TONS of people start seed business' from their home garage. Apple and IBM began that way. The main thing is to set up some objectives or business ideas and then tailor your setup accordingly.

[05450x]

Bummer. I guess my real question was would I need to cut new seats and/or lap the valves?

[briansmobile1]

@05450x Yes.

[05450x]

Help me out Brian. How do I find your video on the actual replacing of the valves?

[briansmobile1]

@05450x I filmed it and my hard drive crashed before I could get it on.

[jamesgarcia13]

Im curios. I have a 2005CRf450r and i have really low compression and it backfires when i try to start it. intake valves am i right?

[briansmobile1]

@jamesgarcia13 Your timing could be off a tooth or yes.. intake valves.

[PEARCEx77]

ill just try it. putin the bike back togetha now anyway lol



[PEARCEx77]

pro-x

[briansmobile1]

@PEARCEx77 That makes more sense. I don't have a great deal of experience with those.

[PEARCEx77]

ive got a set of prox ones as cant get faction mx ones in the uk. has you ever herd of prox steel valves breaking?

[briansmobile1]

@PEARCEx77 I've not heard about Prox valves till just now. I wonder if they're the same like volkswagen and voxhaul?

[PEARCEx77]

do you defo recomend the steel valves over the oem ti ones? herd a few storys that the steel vavles brake???

[briansmobile1]

@PEARCEx77 Kibblewhites break and their customer service is horrible. Faction MX are a single piece construction. They are the way to go.

[jdeshong08]

Good video but I wish you explained how you got the new valves to seat properly? Lap them in or had the seats cut?

[briansmobile1]

@jdeshong08 lap em like a thirsty dog. See the wood lapper tool on the right there?

[RoCkStArRiDeR410]

somebody plz respond im needin this bad

[RoCkStArRiDeR410]

hey brian i just got my 2005 crf 450r a month ago and its very hard to start and it only starts once even after its warmed up it wont start i got to wondering if its the valves or the piston ring if there worn out. i need some help ive tried alot but you can pull start it and it starts right up after it starts it runs pretty good but i can tell i have lost some power. what should i do?

[briansmobile1]

@RoCkStArRiDeR410 That's MOST LIKELY valve adjustment. You'll know for sure once you measure your intake valve clearance. Check out my valve adjustment video to see how.

[RoCkStArRiDeR410]

@briansmobile1 i tried to stick a feeler guage in between cam and top of valve and i cant get anything in between it its bottomed out both of them so what know i watched your video alott and finally figured it out i do have titanium valves but the faction mx valves would require less maintnence but at higher rpms the bike stops running right is this true thts what i heard

[briansmobile1]

@RoCkStArRiDeR410 Mine have been AWESOME. Titanium is soft. Get stainless and you'll be great. If you can't get a feeler gauge in then you NEED to adjust/replace your valves.

[nickiz1]

so my new kibble intake with 2hrs snap'ed and froze my motor ! :D go Honda ?? why :(... why :( ..made a real nice video of it and a video of that day you can here on how hard i was riding :(... just dont get why 700$'s for 2hr's of half ass riding ??

[briansmobile1]

@nickiz1 Kibbles do that. They are cast in two pieces and then bonded. The one's to get are called Faction MX. They are the best. They're made here in Utah. Check out my valve adjustment vid for contact info and get some! If you do the complete set you'll not have to adjust pretty much ever again.

[nickiz1]

@briansmobile1 this last rebuild took all my money:(.. trying to trade it for a 2000 or newer cr250 or 500 ??nice replyin again mr brian ! may the dirtbike god bless the path of plenty of mud :D

[BigManlyMan4]

@briansmobile1 are the YZ450f titanium valves a different/stronger grade than the crfs?

[briansmobile1]

@BigManlyMan4 YES! I don't know the specific metallurgy, but experience of mine own and of others indicates they last much longer.

[BigManlyMan4]

@briansmobile1 I thought so! Someone told me they have 350+ hours on their YZ valves. I just rebuilt my YZ. Check it out if you want. I only have a short video. I have videos of the rebuilt process just waiting to be uploaded.

[DrumHonda]

@briansmobile1 I am wanting to replace my stock crf250r valves with Steel ones. What do i have to do to get them to seat? Can i do this stuff at home?

[briansmobile1]

@DrumHonda You can. You lap them with lapping compound. It doesn't do a dang thing to the valves (hard like a diamond) but makes the valve seat conform tightly.

[goosegirl615]

Sorry to sound dumb. But how do I know what the shim size is that is currently in my bike. I just checked my clearance and the RT is .005(0.10mm) and the LT is .004(0.10mm). I can not figure your math out. When i look at my feeler gages you said on your o

ther video yours were .0015 and it is .04mm but you used a different number than that in your math. What am I doing wrong here? I know this is a lot but I just do not understand.

[briansmobile1]

@goosegirl615 THAT is a very good question. The old shims are marked. When you pull them out you'll see a number stamped on them. If they're worn off or have been changed with cheap knock off brand shims you'll have to measure them. (they'll be blank with no # on them) Just keep track of which shim came out of which spot to begin with when you tear things down. Then as you do that valve measure if needed to get the correct measurement of the shim to use as your "current" value. Good luck!

[warrenfoxgrey]

Hi Brian, great video. I have a question. If I were to change all my valves and shims to brand new ones - will all my shims have the same thickness?

[briansmobile1]

@warrenfoxgrey No. Not likely. the valve seats will not be uniform in distance with respect to the bridge in difference.

[forumboarder167]

your videos are some of the best on youtube...thanks so much for all the help..you've saved me lots of money

[briansmobile1]

@chelonia1663  You're welcome. FactionMX are the real deal.

[briansmobile1]

@chelonia1663 Interesting. Have you had experience or friends with that happen? Kibblewhites are a two piece that are bonded and can split and destroy your head, but now there's FactionMX one piece construction that are awesome.

[stacyjpearce]

I just got this bike, It won't start, so I checked the valve gap and I doesn't have any. So if my shim is a 1.55 on the intake side what shim should I use?

[briansmobile1]

@stacyjpearce Subtract the spec in your manual of what it should be from 1.55 and use the shim that's the closest to that.

[briansmobile1]

@stacyjpearce 1.55 is pretty small. You may need some new valves. If so I recommend factionMX valves. My valve adjustment video has the contact info.

[stacyjpearce]

ok, I just go this bike, It won't start, so I checked the valve gap and I doesn't have any. So if my shim is a 1.55 on the intake side what shim should I use?

[RcRacer8]

So is there a way to start with no shim, and add up to get the desired gap?

[briansmobile1]

@RcRacer8 No shim is equal to a shim that is flush with the top of the shim pocket.

[719boosted]

Good video bro but you never said anything about the springs do I use the stock ones buy new ones an do I have to have my seats cut to take the new valves this is my first thumper was a 2stroker man but very good video 

[cat123456789101]

how come motocrossers dont have push rod and rocker arm motors? or flat head motors

[briansmobile1]

@cat123456789101 Power to weight ratio. Good question!

[cat123456789101]

@briansmobile1 do you think that what i just said would work good ? with a flat head , if the valve falls off it would not hit the piston would it

[briansmobile1]

@cat123456789101 Not sure- flat head motors are not my specialty.

[352pimpz]

@briansmobile1

hey i just got a crf450 06, im new to four strokes since i just moved on to a 450 from a 250 two stroke, but i need help, my bike backfires on deccleration, what could be the problem? spark plug? valves? pilot?

[briansmobile1]

@352pimpz Most often it's jetting when that happens it's too lean going into the corners creating a misfire. look at your jetting charts in your manual. ( I think between pgs 119-126)  It's the middle jet circuit.

[gilessmokey]

@cat123456789101 motocross bikes avoid the pushrod system because it adds reciprocating weight which can`t do high speeds, pushrod also adds wearing joints.the honda does use a rocker for the exhaust valves though. flatheads =low power and efficiency.

[cat123456789101]

how come motocrossers dont have push rod and rocker arm motors?

[Rideshadow07]

thanks man and same to you, i didnt mean to post on here twice it didnt show the pose right away so i tryed again,i guess ill take it to a local shop cus i have no clue how to mess with all that stuff in the 4strokes

[Rideshadow07]

i have a 05 crf450r with stage 2 hot cams andits making a ticking noise what can it be?

[briansmobile1]

@Rideshadow07 Ticking can be too much valve clearance, insufficient lubrication, or sticking due to infrequent oil changes, or tiny little witches banging tiny cauldrens of bat wing broth. Happy Halloween Brotha!

[250CFJ]

@Rideshadow07 my 2007 CRF 250r is making a ticking noise to and i have noidea why, what can i do to fix it??

[Rideshadow07]

hey quick question u seem like u know alot aout the crf450, i have a 05 crf 450 with stage 2 hot cams ,the bike starts first kick and runs great but there a chatter when its runing its been that way sense i got it off the guy, i had to put the stock pipe back on to ride where i do now and it seems the chatter is more noticable now.sound like its comen from the kickstart side of the motor twords the exaust port ... what can that be??

[kolias89]

Hey man really helpfull video!

I just wanted to ask you!

I have a CRF250R 2005 and i was wondering of adding stainless valves on it!

Is it safe for my CRF if i add those instead of titanium valves?

I found on ebay stainless valves exact for CRF250R but just wanted to ask you!!

And one more thing...stainless valves are same for 250 and 450 crf's?

Thanks in advance!!

[briansmobile1]

@kolias89 Glad you liked the video. Stainless valves are the way to go. Get the kit that includes the springs, and bases for the springs. The 250 is different valves than the 450.

[kolias89]

@briansmobile1 Thanks a lot for your quick reply man!!

Can you please suggest me a brand and if it's possible send me a link of a kit! i would appreciate it a lot!!

I am a newbee at those things so i don't want to do a mistake, hope you understand!

Thanks again!!

[Jolinator]

really great video

[briansmobile1]

@Jolinator I'm so glad it rang your bell!

[woodsyir888]

very helpfull cheers mate

[briansmobile1]

@woodsyir888 You're welcome!

[dirtastegood]

Do you think that it is ok on the head if you run the stainless steel valves in a stock head? Because the head is designed for the titanium ones.

[briansmobile1]

@dirtastegood ya, it's totally fine.

[briansmobile1]

@MrCrf450rider Thanks for sharing! I am aware of that. You really gotta visually line them up. A lot of bikes actually have that condition. The solution is there's a small nub or notch to line it up. If you don't have one, I will often just make a notch.

[MrCrf450rider]

I've seen valves mushroom really bad, to the point I didn't even know how the bike ran.are you familiar with port lineup on oil filter cover?it can go on either way,but you gotta make sure it's the right way.I noticed that the first time I changed the oil on my crf.just mentioning.nice vid!

[travisneil]

i did put kibble white valves in my last bike but only ran it for about another 10hrs before i sold it so i didn't get to see the results

[travisneil]

good video, im not sure all of it is valid though. I don't think stainless steel is harder than titanium, definitely not all grades of it. Even if you did have perfect valves its still going to be a high maintenance bike you will probably just have to machine the valve seat on the cylinder head because it would not be weaker than the valves right?

[piratesnz]

thanks a lot..briliant video...

[briansmobile1]

@piratesnz Glad you liked it!