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Crank in "Non-Servicable" 08 CRF450

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So I think I need a new bottom end rod bearing. My motor sounds a lot like this guys:

http://www.youtube.com/watch?v=XQmG3Tpe3Wc

I called Monarch Honda in Orem Utah and they said that the crank for this bike is a "non-servicable" crank.

You mean to tell me I can't just have the crank rebuilt like every other crank I've dealt with?

Thoughts?

PS - Typo in the title, I meant to say "is" not "in"

Edited by jethro450
stupid typos

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The Honda Shop in Orem just told you "they" don't service the cranks. They can be serviced but most of the time a new part costs the same or less so why bother.

The one issue of the Honda crank is the sprocket side runs in the bearing itself. So you can change the bearing in the case, but the crank pin the bearing runs in is going to still have wear or a compromised bearing race (not new)

By the way, listening to that vid makes me want to reach into the computer and hit the kill button ASAP

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The Honda Shop in Orem just told you "they" don't service the cranks. They can be serviced but most of the time a new part costs the same or less so why bother.

The one issue of the Honda crank is the sprocket side runs in the bearing itself. So you can change the bearing in the case, but the crank pin the bearing runs in is going to still have wear or a compromised bearing race (not new)

By the way, listening to that vid makes me want to reach into the computer and hit the kill button ASAP

I WANTED TO SHUT IT OFF TOO! :prof: Luckily mine doesn't sound quite that bad yet.

The way the service guy talked to me was like, "it cannot be done". Not just that they don't do it, that's why it bothered me because I know it's possible but you are correct, it'll probably cost the same to just buy a new one.

I guess I'll just bite the bullet and buy a new crank. Not the first time I've split a 450 case...

PS - the motor has 80 hours on it, 40 of that was with a 2moto snowbike kit on. Stock valves haven't budget even half a thousandth since day one, piston looks perfect, everything except this pesky rod bearing.... :smirk:

pps - my youtube is jethro450, lots of snowbike vids for ya if interested :smirk:

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So where's the best and cheapest place to buy a wiseco bottom end kit (crank, seals, bearings, etc.) that I've seen in the Tucker catalogs for $300 or so?

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You can buy a brand new OEM crank from Apache for only $267.

I wouldn't use a China crank in any of my bikes.

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More questions, sorry: I have a crank i took out of my 06 450 that blew up (I bought the bike blown up and fixed it). That crank actually "seems" ok. Zero up and down movement on the rod, side to side is in spec. I'm half tempted to throw that in and try it. My only hesitation is that I can't test if the rod itself is bent or not and that's why I didn't use last time. Any good way to check the alignment of where the wrist pin/bearing connects?

Anyone tried a stroker Hot Rod crank that adds 3mm to the stroke?

stroker kit 16-4152

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the inner bore of the rod wasn't perfectly round, but it's dang close. the vertical direction measures 0.001" longer than the horizontal. there IS sign of wear though, and for that reason I don't think I'll use it.

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Got the motor out tonight (I moved over the last month, been too busy to get to this).

Couple thoughts:

1. Rod has ZERO up and down movement, makes me think the crank is fine.

2. The piston looks perfect, but can rock side to side within the wrist pin more than what I'd classify as "slightly".

3. I might be running just a tad lean, what do you guys think?

4. I can't get the wrist pin out. Not sure if the piston is moving a little and caused some warpage in the wrist pin clip area or something but it is definitely not coming out. The wrist pin can slide both ways about 5mm and then it hits metal to metal and isn't going anymore.

So... questions...

A. You think I just have piston slap? I had that on a few two-strokes in my day and it just doesn't sound like that to me. If so, I guess I could dremel out the inner part of the piston and get the pin out, then install a new piston.

B. I feel like I'm just guessing at this stupid noise and wasting money tell it goes away. My inclination is to buy a new crank, piston, and cam chain tensioner and see what happens. What do you guys think?

getimage2.jpg

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monarch is so full of d-bags that dont know jack. if you need parts and servace take it to USA Motor toys and they will fix ya up, 801 - 796 - 7416 ask for Matt he is the servace guy and can get you lined up for wayy less then monarch

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i rebuilt the crank in my 09 kx250f, new crank pin/con rod/ cage and bearings, good as new, also had the crank balanced and it was in spec.

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The top of the rod is where the rods go bad most of the time. I wouldnt run it if its not round anymore. Youre asking for a really big expensive failure if you do.

For the cost of rebuilding the crank you can buy a new one and you wont have to wonder about the crank pin that runs in the bearing on the stator side (that isn't rebuild-able, all you can do is replace the bearing in the case, which you should do anyway)

Other than that, I think your parts list for the rebuild is good. New piston, new crank, a manual CCT and a new cam chain and if the valves havent move dont mess with them. Just leave the head together.

And its not lean. I looks pretty good actually, for pump gas that is.

Should be good to go. If you cant get the pin out of the rod, try an air hammer. Ive had to go this route a couple times when the pin was seized in the top of the rod. It'll probably come right out. My air hammer cam with a pointed attachment that works great. Normally you just have to push it past far enough to drop the rod out.

As far as the rod goes, think about the spec. The rod pin hole is .7491" +/- .0004".

Its plus or minus 4 ten thousandths of an inch. The max if the hole is round is .750 and if I found one that big, I wouldnt run it. The clearance spec is only .0006". Its less than one thousandths. If you measured .001" of slop (which you may be able to hear but not feel) its too much. The top of the rod is toast.

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I hate spending money but I'm going to put new crank bearings in the case while I'm at it. I'll order parts today and maybe post a picture or two and a follow up response in about a week when I get it all put back together. Thanks for your responses fellas.

PS - I read some other long thread on here about jetting a year or so ago. I'm running a 160 main on the second clip for everything above 5000', winter, summer, it doesn't matter. I put a 165 in when I go to lower elevations (2500-5000). My bike runs super crisp and clean .... and has a crank issue... lol

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