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Lots of people have different opinions about how to break a new engine in. I tend to lean towards the HARD break in. I have always broke in my new engines...whether a new bike, or rebuild the same way. Make sure they are up to operating temps and cooled down a couple times...then the 3rd time...go thru the gears while it warms up...once up to temp...POUND it like it will be run the rest of its life. Did it with this one and the bike just feels better the more I ride it. The fuel mileage went up as well. No ill effects yet, and I have 20 hours or more on it (5 tanks of fuel). Hard Break In Here is an interesting bit of info I ran across the other day on a website... 3wheelerworld.com They were all going back and forth about break-ins there as well. I never saw his theory before but I guess I have been doing it similar to his way for some time now. Never had an engine fail. 20 years of riding racing and building..good so far. PC...you should try to be a little less abrasive with your comments...it puts people off. Get those top speed runs posted with some other gearing please. Later
 
Quads get faster as they break in? I dont think so. I dont think im going to gain a single MPH till I change the gearing. You can break yours in like a girl and Ill break mine in the right way, Hard. But thats just me. Just for your sake of BS, ill put some more time on the machine tonight and do another run for you and post the tops speed.

I dont see why anyone would disagree, I got the bike, I did 2 runs and I got a top speed,WOT down the road pinned. I guess if I want to blow the motor up I can hold it for another minute and maybe squeeze 70 if you want. Its just not a fast 4wheeler, its geared that way.

Jeff[/b]
I think that while engine does break-in it will start to run better. But I do agree with Jeff that topend won't change much without a gearing change.
 
I was not trying to ridicule you in any way. I appologize if that is the way you took it. I am not new at this either, but i dont want someone who is new to go and spend 7K on a new quad and go break a ring by bouncing the engine off the rev limiter ice cold. These threads are to offer opinions and advice, not for picking on people or belittling people. Again, I appologize if I offfended you.
 
i too am interested to see what effect the sprocket has. I agree when the hard break in as well. My buddy has broken in anything he has ever had that way and never had any problems, to include his kfx 700. Same with drag car and drag bike. I thought it was common sense to let your quad warm up before driving it like you stole it. Maybe thats just me though.
 
The top speed was 73.4 with the new front sprocket. The sprocket is the same sprocket for a YFZ450 and it also said KLX on the package. They double checked the numbers and its for a KX450F bike and the rest I mentioned above. Only problem is the sprocket spacing is a bit different on the KFX450R cause it has a 1/6th lip to make the sprocket stick out more so it doesnt hit the case. I rode around a while and everything is sound but I had to modify the front case saver to make the sprocket fit. Its too close for comfort in my eyes so I am not going to be running this sprocket for that long. I am going to get a new rear one probably a few with 5 or less teeth. Ill report how it goes when I get them.


I hate to say it but I am overly disapointed. This machine is corcked up and I dont know what to do without spending tons of money. Right now I am buying the Dynojet power commander and Ill see how well that helps. They ran out of trinity exhaust and air intakes so Im screwed from them for a while. I am also buying some cams and I hope by the time im done I wil be happy.

Other than that this machine has a lot of low end torque and power but when I got that new sprocket on, there was no top end at all. Ill see what I can do.

Jeff
 
The top speed was 73.4 with the new front sprocket. The sprocket is the same sprocket for a YFZ450 and it also said KLX on the package. They double checked the numbers and its for a KX450F bike and the rest I mentioned above. Only problem is the sprocket spacing is a bit different on the KFX450R cause it has a 1/6th lip to make the sprocket stick out more so it doesnt hit the case. I rode around a while and everything is sound but I had to modify the front case saver to make the sprocket fit. Its too close for comfort in my eyes so I am not going to be running this sprocket for that long. I am going to get a new rear one probably a few with 5 or less teeth. Ill report how it goes when I get them.
I hate to say it but I am overly disapointed. This machine is corcked up and I dont know what to do without spending tons of money. Right now I am buying the Dynojet power commander and Ill see how well that helps. They ran out of trinity exhaust and air intakes so Im screwed from them for a while. I am also buying some cams and I hope by the time im done I wil be happy.

Other than that this machine has a lot of low end torque and power but when I got that new sprocket on, there was no top end at all. Ill see what I can do.

Jeff[/b]

Thanks for the info. I'm confused, a larger front sprocket hurt the topend. This thing must really be corked up. The unfortunate thing on buying a early first year model is that parts take awhile to come out. We do appreciate all of your work and info. :tups:
 
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