I'm not up on quads, so what is it? Looks like fun though. Double wishbones in front with remote reservoirs.
2006 Yamaha YFZ 450. Those are extended aftermarket a arms in front. Shocks are remote reservoirs, and are adjustable (stock). I don't really know anything about them, either. First one. They look easy to learn, though.
Stock shocks up front, or at least it looks that way. Looks like it is in very good shape yet too, congrats on the purchase! Fuel Injection is always a plus too!
I saw a few like this in Nagoya today that were titled to be driven on the street. how kick ass would that be haha
I agree. :biggrin: 5 speed, no reverse. Taking two days off from work and heading up north tomorrow. Going to give er a sort of inaugural couple days of trail riding.
Well, ****. That was short lived. Skipped out on work for two days to go up north and ride. Half way through the first ride it sputtered and lost power and died, and then the engine seemed seized. I did have the FSM on my laptop with me, so I took the engine half apart - to check the timing see if it jumped teeth or something - and came to the conclusion that I'm pretty sure the piston broke, probably dropped a skirt, and some piece(s) are jamming up in the crankshaft. ****.
Yeah. Sucks for sure. I'm betting the seller knew, but there's a chance it was bad dumb luck. Top end looked perfect though, so I doubt I'll be out any more for this being a 4 stroke than I would if it were a 2 stroke. Assuming the crankshaft didn't get damaged (from what I've been told, it sounds like a counterbalance on the crank is what's likely jamming up against broken pieces and the bottom of the engine case), it should just be new piston & rings and good to go. Just a guess, though.
Yeah, hopefully that is the case. It is pretty common for guys to pick up a used bike/quad only to have it grenade right away on them -- especially on newer machines. Basically they will buy the machine new, not service it at all and then dump it off on somebody else.
Not to be a **** but the first thing I thought when I saw the quad was "wow that looks beat to ****". Good luck on however it turns out. This is why I buy my used bikes from people I know the service record on ... ie my dad
god your a moron chet. maybe you buy used bikes only from your dad because he gives them to you :ugh:
Yeah I want a wheeler or bike that has a number plate on it and a bunch or parts/goodies that makes it look raced ... And no All the toys I have bought off my dad thank you.
To me, other than the obviousness that it had been raced (seller said he bought from his friend last year and added all the "goodies" so he could race it - kill cord, etc. - and he ran it a couple times), it just looked like a wheeler that had actually been ridden (as opposed to the ones that look like they get driven around the back yard a couple times then parked in the garage indefinitely. I wonder now if it was hands down a bad idea to buy one that had been raced. None were available in the time frame I wanted to stick with that weren't a gamble in more than one way, and I appear to have lost, to a degree. Oh well. Such is life when you're terribly impatient (as I am). I'm going to be tearing it down completely to see whats really wrong this weekend, and then fixing whatever needs to be fixed. With the help of an experienced friend, I'm hoping I won't be out too much in the end. The seller did actually answer my call this morning, which surprised me. He had nothing really to say though, except oh that sucks I had no idea anything was wrong blah blah blah.
I was going to mention, odd thing about this was that the oil & spark plug looked really, really new. I did check them before I bought, and it reinforced the sellers overall story of the quad's history (maintenance done last fall, only ran a couple short times since). Now I wonder if it wasn't a cover up.
oh no its been raced! its going to fall apart now, because its NOT meant to be beaten to death just like every other off road machine!!!!
No, it was a bad idea to buy it from somebody who probably never did any real maint. on it. I'd rather buy a bike from a competitive racer (they usually take care of their stuff) than some spode who beat on their machine and never even knew how to clean the air filter.
Exactly. That's why I went ahead with a machine that had been raced. I buy as much based off my impression of the seller as anything, and this guy really didn't seem like the type to have not maintained it. I saw some of his other vehicles and talked to him about the quad for a good bit and from what I was able to visually inspect pre-sale it seemed legit. It even ran great for the first hour and a half - pulled hard. But, in the end, its still a crap shoot. Air filter was immaculate, btw.
Well it sounds like perhaps you just got a case of bad luck. On the bright side, bikes/quads are soooooooooo much easier to work on (and cheaper) than Subies.
I too have taken the short end of the stick when buying a used toy. Well not so much the toy, but a newer engine for the toy. Spent $550 on a used jetski engine to have it last less than 3 hours before blowing up the rear cylinder. 2-stroke or 4-stroke, if it's going to blow...you can't do squat. It's going to go!
Hmm .. I'm searching around the web a bit, and I ran into (again) info on an oiling issue that existed in the 04-06 yfz450's. Apparently the splash oiling used for the wrist pin and rod bearing is insufficient and at high rpm either, but usually the wrist pin, can suddenly fail leading to broken rods and seized engines. It sounds unfortunately common and isn't linked to poor maintenance. In 07 Yamaha switched to a higher velocity oil pump and added a squirter nozzle to lubricate the wrist pin area. There's a documented DIY mod that requires drilling an oil passage through the block, also an 07 cover/pump assembly can be installed, or there's an aftermarket option that's a bolt-on all parts included affair. Hopefully the internal damage will tell the story, but this sounds like a good candidate. You can bet I'll be looking to see if the wrist pin fused itself to the piston or something.
Disassembled the engine today. Lots of metal shavings. Main rod bearing is definitely fubar'd. I think that happened first, allowing the bottom of the piston to slam down into the crankshaft. So, it's rod, bearing, piston, wrist pin & bearing, oil pump, bunch of gaskets, and a new cylinder (they're nickel plated, so no bore & hone - replating is more $$ than a whole new jug), and various gaskets. OEM parts are coming in around $500. May put some upgrades in, like a big bore cylinder & piston maybe. Probably not a stroker crank, though. It wasn't the oiling issue, but I think I'll preemptively do that upgrade/fix, too. I guess it came out kinda blury (cell phone), but you can see the sparkly shavings in the upper right (which is the bottom of the crank case). It was absolutely thick and came out in gobs with big shreads of metal in it. :eek3: View attachment 16694
That sucks man. Not good to hear. I would shy away from the big bore kit unless you know for sure that the 450R motor can handle it. The positive is that you have liquid cooling which can help keep it cool, but I know for some other models cooling becomes a huge issue with big bores.
My buddy says despite the considerable dings in the crank there (2nd shot), it should be okay to run (not a contact surface or anything, they're just kind of some big heavy plates on the crank). Second opinions?
Your lucky that wrist pin didn't give way or you would definitely be replacing the jug. I'd run the crank. Looks like a couple little dings in the counterweight, nothing serious. Just make sure nothing interferes with the rod.
Yep, all I have to say is my 06' yz 450 cost about $2k to fix after everthing was replaced, It was only one year old, the bike was clean but the new four strokes are tweaked! they say the yfz motors are milder and take more abuse. I would double check everything in the manual and take the time when you put it back togther, Good Luck!
He could do that, but taking it to a wire wheel to clean up the gouges in the counter would be a wise choice. I would just buy a new crank, after all it obviously took some hits if the skirt and wrist pin wells are cracked.
I think I'll just buy a new crank. There is some cost involved with rebuilding the crank because the counter weights or whatever have to be heated up to release them. That puts me near the cost of a new crank/rod assembly. For the small amount of extra $$ I'll take one that hasn't been smashed into by the bottom of the piston and hasn't been heated/cooled for disassembly/assembly multiple times. Also, I'm seeing that the go-to mod here is an OEM wr450f crank assembly - lighter rotating mass and different wrist pin that seems to have less trouble than the yfz450 pin, but otherwise bolt-in as long as I use wr450f rod, piston, rings, wrist pin, circlips, etc. I just need to pair that with a piston for a wr450f, but I'm not really sure how to pick one and know that I won't have issues. For example, I'm reading the wr crank ups the compression on pre-06 yfz's, but nothing about 06+'s - so if I buy a 12:1 aftermarket wr piston (has to be wr to match the wr crank/rod/wrist pin), will it still be 12:1 in the yfz. Also, I see mentions of squelch and valve clearance/different thickness headgaskets, but nothing specific yet to the wr crank/piston setups. And of course, I have no idea how much of a bitch it will be to get the jetting right if I do all this crap. Just talked to the guy who does the oil mod, and he says good to go with the wr setup, so I guess I need to start rounding up parts. I probably should just go stock, but something inside me fights that and says "upgrade!"
IMHO, rebuild the motor back to stock. The best mod that $$$ can buy is suspension work. All the power in the world isn't going to help if you are either a spode or are bouncing around everywhere and can't put the power to the ground.
Its not so much a "want more power" deal as it is a "heck, as long as I'm replacing all this stuff and an upgraded ______ is only $xx more." But ... I totally hear your point. I can't say I've made all the best choices on the Suby, and given the chance to go back I would do things differently in places. That said, I'm having a really hard time finding anything against throwing a fully stock crank/piston setup from a wr450f dirt bike in the yfz. Same stroke but longer rod (apparently less side-force on the piston skirts = less stress/wear over time), 1 pound lighter rotating mass (counter balance shaft is same part # between wr450f & yfz450, as are many, many other engine parts), smaller wrist pin (= more piston material around the pin = better), and bumps compression from 11.4 to 12.5 (puts me at the limit of pump gas, trying to avoid 100+ octane), and of course OE quality control (whether that's good or bad I guess is debatable, lol). Basically the exact same price as stock yfz450 bits and no gotchya's that I can find (unlike, say, a hotrod stroker crank that appears to be a cheap upgrade but really would need an expensive true/balance), and it seems half the yfz owners out there have done (exaggeration, but it seems to be a very common mod when a full rebuild is needed) it so it should be fairly well proven. Decisions, decisions. I'm also nervous as hell that I'll **** something up or miss a shot bearing or something and have another immediate and severe engine failure. I know I plan to clean every part thoroughly and replace anything that seems the slightest bit off.
Ouchy. Just finished ordering up all the parts. $200 for the oiling upgrade. $95 for a full gasket kit. $900+ for all the dealer parts. (replacing shift forks and water pump, too) So $1200 altogether.
my freind has a yfz with over $20,000 into it. it sits in a shed and never gets ridden. He had the same problem you did, piston just f'in broke one day when out in a pit. He did the same thing you're doing now... "well i can buy this for $x or this for $XX.... just like i did on my wheeler as well. THOUSANDS UPON THOUSANDS later.... they all end up just sitting around. GL with the build man. Dont go overboard.
It runs!!! We got the engine all back together and into the quad last night. During assembly of the head we accidentally let one shim on each the intake and exhaust side get out of place. We kept wondering why it felt like we had no compression, until we tried to start it and it was backfiring out the carb. Put the shims back in place and all was good. Started right up. The wr450f crank and piston are in. The weight savings appear to be mostly in the rod, which looks like some kind of steel composite maybe - not cast iron like the oe yfz450 rod. Can't wait to see how the combination of higher compression and retarded exhaust cam do on the trail. I might put the cam back to stock if the low end is too weak. But, yeah, it runs!!
I was just cruising some of my old threads here. Got sick of the horrid jagermeister sticker on this beast and had a couple wobbled out heim joints. So I did this Changed er over to black plastic with orange decals, matching black hmf pipe and gas cap, orange radiator hoses and bar pad, new skids, maybe more, I forget. Then we picked up another yami for the wife, 07 wolverine sitting in a dealership in wi with no miles Can't keep it stock though, what fun is that. Intake & exhaust, jetted, wheels & tires, skids, threw the blue cap from the yfz on it. Loaded up and ready to go These are old, did this a couple season ago, foz is even in one. Hope that's still running fuji Didn't get out much this year but next summer our little girl will be old enough to take out into the woods so hopefully...
