Cannondaleriders

Quad made a grinding noise at group ride then locked up.Didn't let it bother me and still had a blast at the ride.Total hrs on quad was a TRUE 92HRS.Motor oil was changed 8 times and tranny oil 3 times.Had to replace 2 clutch cables and 4 sets of rear brake pads (and now needing another set(5) and one set of frt pads.Frt tires 50% wear, rear 75% wear.Put new chain & sprockets on when rebuilt used a 13 frt until it stretched enough for a 14th.Chain now missing rollers and sprockets shot.Normal wear.Also cleaned air cleaner at least every other ride sometimes every ride if very dusty.Ran 11,500 ver limiter for the 1st 85 hrs and then 10,000 rev limiter for the remaining 7 due to trying out a breakin map and not having time to switch back.For almost all of the riding rode it hard and into the rev limiter.Mostly hard trail riding(majestic) and some track and drag racing.In this time period up until now it was trouble free beside normal wear & tear.

Motor had a head from an engine with a locked up crank on it with unknown hrs.Should have replaced valves and spring before using.Had 450 wisco pison with coating 2mm stroker crank.Crank had new replacable pin,z400 bearing, and stock cannondale rod.Rod had .0008 wear from c'dale new rod specs and .0013 looser than suzuki new specs(it was a cdale billet rod).Tore it apart and found out it threw a few valves.Most likely from spring and valve fatigue from running the 11,500 rev limiter extensively.I usually run 10,800 but put it higher for crank testing.The one exhaust cam lobe was almost round .210 wear and the other had about .05 wear. Back side of the excessively worn lobe was also worn as if it was slapping against the valve bucket instead of rolling over.Was basically running on one exhaust valve.Intake cam looked great.Surpringly enough head looks salvagable.Valve pockets have very little damage.Here's some pics.

Piston looks just as bad and has hole through it.Sleeve looked like new besides big gouge.

Piston evaluation.Not impressed.Had the piston coated for wear resistance on the side and ceramic coated on top for heat.Highy recomend coating held up excellent.No wear of the coating or piston except for the bottom of the edge of the skirt.

Used 97mm wisco piston before with cast sleeve had to tear down in 15 hrs from previous crank.The piston had alot of wear on the sides for the amount of hrs and the wrist pin was scarred and tight in the piston and had a heck of a time getting out.For this reason I had the new piston coated and put bigger oil holes that broke out below the bottom ring to lubercate the wrist pin which really helped.The wrist pin with 92 hrs looked better and came out easier than the 1 with 15hrs,but still a little tight getting out of the piston.

Piston however was very sloppy.From 92hrs of high rpms the skirt on the bottom side measured 3.798 and at the top 3.810.New piston numbers are 3.815 at bottom and 3.810 top.The piston showed no signs of wear easily to tell from the coating but from rocking back and forth at high rpms it was smashing in the sides of the pistons due to such a short skirt.If it wasn't coated it surely would be worse.I took a stock pison that had about 140-150hrs on it that the crank went out on and measured 3.733 btm and 3.733 top.New was 3.735 btm and 3.733 top.He was running 10,800 cannibal rev limiter and did the same riding as me.At .002 wear on a stock piston 140hrs 10,800 and .007 wisco 11,500 85hrs & 10,000rpms 7hrs.If they had the same wear the wisco would rock more than the stock because the skirt is shorter.Hate to say it but sometimes long skirts are better than short ones.LOL.It would also wear faster because the shoter skirt.I could see that in not a hole lot more hrs, cracking sleeves and even twisting a piston due to excesive rocking could occur.I believe that the stock pistons will last considerably longer, probably why c'dale switched pistons,but the wisco is definately the best bang for the buck for performace and I will buy again until there is something else out there better for around the same cost.I would just want to replace it every 100hrs coated and every 75 uncoated if running it very hard.Oh the rings looked great probably from nickasil sleeve and keeping a clean air filter.

Here's a pic of the rounded cams.Looks like I'll be doing some welding and machining.Notice the lobe opposite the decompression.Round!Surprising it ran.

The sleeve I was very impressed with.The nickasil sleeve mic'd the same as new 3.8185 and showed no signs of wear except for the gouges from the valves.I'm sure the piston coating also helped the lack of sleeve wear and scuffing.I took the cast sleeve that had 15 hrs on it and it mic'd 3.821. 0025 wear in 15 hrs.I'll stick with the nicasil. Didn't get the crank out yet to check but felt great.No excessive slop or rough spots.Never steel in the filter.A used c'dale rod with wear & unknown previous hrs. with z400 bearing and new pin. The pin and bearing are a definate go.Hard riding at high rpms with a used rod and 92 hrs.The side crank bearings also feel fine due to lack of vibration.Don't be afraid to use the z400 bearing just make sure if you do the crank yourself or send it out to make sure it was reassembled correctly within the specs of runout and crank width and to clean out the pin.Plugs can be purchased at an autoparts store. The new rods are another story.They have low hrs and could still fail and will not make anymore until proven.If there is a failure I will cut it apart get it rockwell tested and see why failed, if their is a failure, and change it from there and post all my findings.I'm sure with a lower rev limiter pistons,valves, cams,cranks,liners;everything would hold up longer.When I'm done testing i plan on keeping the rev limiter at 10,800,but when it was at 10,000 it felt like it was at 5000 couldn't go that low again unless breaking in a motor.Not upset at all about being down.Only tempory.Still love the dale and wouldn't have any other machine.

Well look on the bright side . The dropped valve gives a reason to pull the motor to inspect the crank. Did you pop the crank apart to check for wear on the cage? I will have an engine ready to test out your prototype rod soon. Im thinking I should keep the rev limiter to 11,500 to assure max stress being a stock engine. Excellent write up Tim. I cant get enough of the carnage pics.

:mad: :cry: