Bushwa, unfortunately the very design of these engines is somewhat prone to rod failure, mainly for simple physical limits than anything else. We're talking about a very high compression rate with an above-average piston bore, even higher than the 610's 98mm that was already stressing the rod. Adding even more compression and bore (namely 11 vs 12.4 and 98mm vs 100mm) just lessened the already tight margin of error but still maintained a streetbike-like reliability. While I always recommend to treat these engines with care to minimize the chances of failure (mainly rod) sometimes they just fail. On the other hand there's plenty of torque and horsepower AND funto be had with these high performance singles.
Hi mg94, I've heard the same from another well respected engine builder from another MC forum I frequent. Roller bearing rods are prone to wear/failure, and he's done a ton from single cyl 2 strokes to 4 stroke quads, etc. I guess I expected more than 10,000 miles. More frequent oil changes will be in my future.
Hey bushwa, That's definitely helpful, i'd say 4000 km should be good enough. I'd recommend using quality synthetic oil (not implying you neglected it ), and also avoiding many high revs, especially when the bike has yet to warm up completely. I'd also recommend to keep the bike on idle when starting from cold for a while, just to be extra safe. These little things are actually useful for every bike out there, but high compression singles tend to be pretty sensitive about temperature of exercise and oil. Keep us posted!
Add to this the fact they are ungodly lean on the big end as delivered by the dealer, even with the PU kit. Get some crappy gas and detonation is hard on those bearings and head gaskets. I'm not sure you can hear it over the exhaust either... .
I do have a JD jetting unit. I've given up looking for a cause and am just going to fix it. I'm making progress, got the bearings all changed out in the left half. I am missing a couple for the right side, ordered those today. Looks like you can buy a rod/pin kit without bearing for pretty cheap now on eBay from Royal Rods. Think I'll look into them, I could always rebuild my old crank, pack it in some preservative, and put it on the shelf, ready for next time. I can ride this bike 10,000 km a year, however I don't wanna be doing a rebuild every season, that just seems unreasonable. Guess I'll just ride the ol Hawk and KDX more. :-(
I'm in the process of rebuilding a Husaberg FS550e motor, these Husky motors are 10x as reliable as the Husaberg... but the Husaberg motor only weighs like 60 lbs complete. Does anyone know the 610 or 630 motor weight? That might tell a good story about reliability Haha.
Update, the reassembly process has begun. New bearings in both case halves are in. Tonight I'll inspect the new crank assembly for true and rod side clearance and hopefully reinstall the gears and crank into the right case half.
So, the assembled width of the used crank/flywheel I picked up is out of spec, under dimension, but the rod side clearance is within, so is the runout, so it went in. Gearbox is in too. Ran it through the gears to make sure the shifter forks and drum is correct too.
Lol. I used it to record, and cross check the actual bearing numbers with husky part numbers and then double check I received the right ones in my order. Oh, and just in case anyone ever uses these photos for a reference, I have the shafts for the shift forks in the wrong locations in that photo. I've been reading manual, installing, then rereading, then back checking the work to ensure I don't miss something just like that.
Well, cases back together, gearbox shifts through the gears correctly, but, it has to come apart again. Something is up with the counter shaft. When I torque down the gear/balancer on the counter shaft, something binds. I'm pretty sure it's one of those stupid metal seals on the counter shaft bearings. I replaced one, but reused another, and, I might have bent one when installing the balance gear. I tapped the gear on and the shaft moved, grrrrr.
Don't know if the end float spec is listed anywhere. At any rate, went at it again tonight. Renoved the gear from the balance shaft, preparing to split the cases again, and a piece of debris fell out. ??? (Wasn't the key, lol) Anyway, put the gear back on, torqued everything up, and it all spins free! Got the other side assembled, and the clutch back together with new bushing. All feels good so far.
Top end back together. Now on to the stator. Anyone have any tips for getting the bearing out of the stator side cover? It's in a blind hole. It feels rough. Tried baking it and hooking it out from the inner race with no luck. Best I got is make a thin tab that I can slip in the middle of the bearing with a tapped hole I can thread my small slide hammer into. Got my doubts it'll get enough purchase on the inner race to get the job done tho.
What bearing is it? One of the starter gear bearings? I'd try heating the sidecover from the non bearing side and when hot banging the sidecover bearing side down on a soft wooden bench top.
It's the one on end of crank, in the stator cover, middle of stator. I'll try that one more time, then order a blind bearing removal tool. Lol.
I don't understand which bearing is that. This is the left side cover of my 610. Can you see it? (Feel free to save the pic and add arrows, circles or anything you want to indicate the bearing).
