I noticed it first when I was riding on a street to get to a riding area. In 3rd gear low rpm, I was hitting the gas for some fun wheelies. As I was doing it, I looked down and and noticed the axle flexing forward and back with every piston pulse. At first I was amazed then I thought to my self --- self, this is not good, that axle is flexing way too much. Not only is the flex a loss of forward moving energy, it is a sign that the axle is weak and will fatigue too easily.

That amount of axle movement was estimated at the outside of the left rear wheel -- not the axle per se.

 

I'll second what raptor720 is saying. I noticed when really lugging down low on some tight trails that it looked as if the tires were wobbling with every power stroke, the guy behind me couldn't get over how much they were shaking either. I never thought about it, but it makes sense that the axle had to be giving way to certain extent. With the Lonestar, it's not nearly as bad.

 

raptor720, Bash
I rode on some hard surface roads today and mine does the same thing. It looks like the tire is giving way kinda like a dragster does when its sidewall flexs on take off. Now your saying this is the movement of the axle. Wouldn't this be hard on the bearings in the rear? Mine does it when I am in second gear shifting into third and then it just stops or settles out as the speed increases. I have never noticed it when just riding on rock roads or on dirt trails. I guess there is no give when on a hard surface so it rears it head more. You are right how it does it with the power stroke. Bash your saying that it does this some what even with a lonestar axle? Is this a problem that they have addressed on the 02 model Raptor? Chet

 

RAPTORYFM660r,

No, I'm not saying it does it with the Lonestar, or at least not as noticeable. raptor720 connected the dots for me. I never really thought about why the tires were shaking so much, just that they were with the power stroke.

 

hey guys, tons of smoke comes out of my blaster. I premix the oil, the injector is taken out. Any clues to why it smokes so much?!?!? (i have a fmf gold series if it means anything)

 

Raptor 720, I didn't mean to be a smart *ss about this smoking thing. Bash is right, we both have a point. But in all the Raptor engines I've built/re-built, I haven't ran into a valve guide issue (maybe intake seat issue). Anyway, based on what Wolverine 16 described, it sounded like the rings. We're still waiting to hear from him.

On this valve seal thing, what I meant is that Raptor and all other current engines uses the spring assist seals (not the old umbrella type like Chevy/Ford V-8 uses which breaks off and cause smoking every time you start the engine and is considered normal).

On the rear axle, under normal use, it's not a problem (I don't know about this flexing thing). Yamaha has to put a fuse in the rear end in case of an impact so the axle bends not the frame or swing arm. For racing, it's not good but keep in mind, if you impact a race axle, be ready to spend some money. Also, according to a Yamaha dealer, he was told that the Raptor rear axle strength level is based off of Banshee.

Now, let's talk 2 stroke Blaster smoking. DG Red, you said you premix. Your smoking sounds like the RH crank seal leaking or worst, the RH main bearing insert is coming loose in the crankcase which will allow the engine to suck tranny oil. (If that is the case, add 2 stroke oil to tranny and quit premix - just add oil as you go. Just kidding I hope).

Take the RH crankcase cover off, inspect crank seal (maybe blown out). Grab the crank end and move it up and down. If it moves, the bearing is out or the crankcase is bad. Good luck and keep us posted.

Wolverine 16, where are you?

 

I think he is probley getting snowmobile trails ready for winter. He will reply soon though. I think his filter sucked some of my roost! hahaha j/k

 

RapTech , i have no clue how to do that? can it blow my engine if i just "forget" about it? Or should i pay 120$ an hour for my local shop to say, its ok, nothings wrong... and use the "We worked on it for 4 hours (**cough 20 minutes**cough) and ahh we ahh found the ahh problem." I dont know if i want to pay 600$ for two idiots to take apart my quad. Well that probably arnt idiots, most likely smarter then me! But anywho, is it a major problem?

 

Wolverine16, did you get a chance to check the intake ports for oil? Raptor720 must be pretty confident to have made the statement he did. I'm sure it would tear him apart to admitt the truth[LOL].

I'm not trying to start anything, I just got a kick out of that comment.

 

Knutz, I am confident. I just hope Wolverine 16 is not a paid DS supporter LOL.

Also, on the ring thing, if dirt got in the intake on a 4 stroke, the dirt would foul the compression and 2nd ring before it got to the oil control rings. Granted, oil could get by the rings based on grooves in the sleeve; however, I doubt that much dirt, if any, got into his engine. The only other way to get oil past the rings is during ring float and I doubt that his 660 could achieve that high of rpm or that the width of the rings would allow the float condition.

By the way, I heard that you were only 100 feet ahead of a Raptor with a slip on at Sand Mountain and that your buddy was only 150 feet ahead. Is that true???