DSBomb - I think it will take about .012" on the one side to get it in spec as well. The other side neede .008". Did you notice a big gain in power afterwards? Where is Salt Lick? We ride a lot in Kentucky. mostly near Manchester/Hazard and down by Fort Campbell too.

 

Holy crap, .012" down from .089! There isn't a part number for one that small on the list at that site the hyperlink is to - do they make a shim that small DSBOMB, or did you have to improvise?
Wonder how/why they got that far out? This all reinforces how important routine valve checks are - the potential for a valve slamming into a 12.5:1 piston just increased in my mind![img]i/expressions/face-icon-small-shocked.gif[/img]

 

Rocky,
Your BMW mechanic works on...well, BMWs. The engine in the BMW Funduro is mostly operated at around 25% duty cycle (horse power used compared to HP available). The DS runs at a much higher duty cycle naturally causing the combustion temps to be much higher which is harder on the valves. They are more likely to "tulip" in higher heat. This is the case with all DSs not just yours.

If you ask the mechanic at the Bomb shop, he will tell you that your shim size is normal.

By the way, the sizes are in MMs not inches

 

JSsDS points out a good example of how fuel/air mixture can effect a lot more than performance. Excessive combustion temps resulting from wrong mixture will only increase the "tuliping" effect on the valves, as well as all the usual piston/cylinder wear we commonly associate with it.

 

Where could I take my ds to see if my valves are adjusted right? What valves are you guys talking about?

I think something is wrong with my ds I have all the things bellow (in my signature) and a stock raptor can beat me, And I know that is not right.

 

<< JSsDS points out a good example of how fuel/air mixture can effect a lot more than performance. Excessive combustion temps resulting from wrong mixture will only increase the &quot;tuliping&quot; effect on the valves, as well as all the usual piston/cylinder wear we commonly associate with it. >>



Why are only the intake valves experiencing the tuliping? The exhaust valves handle most of the heat. Im sure my combustion temps are much higher sice my mods. I will have to try and rejet before Wednesday.

 

I'll take a stab here and guess its because the intake valves are larger, so the distance the edge of the valve is from the valve stem is farther, making it easier to flex and &quot;tulip&quot; by the laws of leverage.

mxz - if you're getting beat by a stock raptor after being piped, tuned right, and replacing the dominators, then its possible that the raptor rider has a good deal more skill in this field. I have a buddy with a very well tuned raptor, and even if he trades my other buddy for his 400ex, he'll still beat his own raptor on the 400ex because he's so good at holeshots and shifting. But then again, perhaps you do have something a little wrong.
You could pay the dealer to check/adjust them, or you could buy the shop manual, read it thoroughly, and then decide if you think you can do it. Its very easy to at least check the adjustment though, and if they need adjusting you could always pay for that, but just do the routine checking yourself. Here's a link for the task: valve adjust

 

I really dont think that he is better skilled then me, I have had wheelers and dirt bikes since I was 7, he has had his raptor for a month and it is his first manual 4 wheeler.

I think I will just bring it to my dealer, they are very friendly and most likely will not charge me to take a look.

Thanks Once Again Hightower

 

Taking it to the dealer is an good idea. There are so many things that can contribute to small bits of power loss that aren't real noticeable untill you lose a drag that you used to win. Or not climb a hill you used to fly up.
One might be the packing in that alba pipe. How long ya had the pipe? More than a few months? Worth a check.

 

I am about 99% sure it is not the packing, the pipe is only like 1 month old.
But what do you think i should have the dealer check out, i am going to have them check the float, the jetting, the valves. what else should i have them go over, what about the cams?

Thanks