Starting Issues

[450Rfutureracer]

Hey everyone tried doing a little search to solve my problem but didnt really see anything that was helpful to myself so I decided to ask..
I have an 06 ER with hrc kit, hmf exhaust, KnN with no air box and I am having a real hard time getting it to start cold or warm weather. I can get it sometimes by playing with the throttle but that sensor inside the thumb housing does its job to well. I have checked and adjusted the valves to spec and also adjusted the decomp arm to spec. Nothing. Cleaned the carb out, all jets cleaned with compressed air. Nothing. Replaced the gas with gas from a different station. Nothing. Check electrical connections and cleaned out with contact cleaner. Nothing. Checked compression after I got it started and read 30psi and needs roughly 50-56psi, so my question is if I adjust the vavles for more compression will it start any easier because the rings do not seem to be blown because I have no smoke coming from the bike and when its running nothing seems wrong. Thanks, trying to figure this one out on my own but just cant do it.

[DnB_racing]

Originally posted by 450Rfutureracer
Hey everyone tried doing a little search to solve my problem but didnt really see anything that was helpful to myself so I decided to ask..
I have an 06 ER with hrc kit, hmf exhaust, KnN with no air box and I am having a real hard time getting it to start cold or warm weather. I can get it sometimes by playing with the throttle but that sensor inside the thumb housing does its job to well. I have checked and adjusted the valves to spec and also adjusted the decomp arm to spec. Nothing. Cleaned the carb out, all jets cleaned with compressed air. Nothing. Replaced the gas with gas from a different station. Nothing. Check electrical connections and cleaned out with contact cleaner. Nothing. Checked compression after I got it started and read 30psi and needs roughly 50-56psi, so my question is if I adjust the vavles for more compression will it start any easier because the rings do not seem to be blown because I have no smoke coming from the bike and when its running nothing seems wrong. Thanks, trying to figure this one out on my own but just cant do it. if you cant get the compression in the right range , with the valve clearance in spec, then you need valve work!

but yes low compression will make it start harder,

try to use a different compression tester to make sure its right, and then set your compression to 55 and recheck your valve clearance and see if it is still in range

in other words tighten up our decompression mechanism until you get 55 psi and then read what your lash is

[450Rfutureracer]

Originally posted by DnB_racing
if you cant get the compression in the right range , with the valve clearance in spec, then you need valve work!

but yes low compression will make it start harder,

try to use a different compression tester to make sure its right, and then set your compression to 55 and recheck your valve clearance and see if it is still in range

in other words tighten up our decompression mechanism until you get 55 psi and then read what your lash is

Thanks a lot for the advice, ending up adjusting the decomp out to .015 when the spec said .011 and it starts and runs like a gem.

[DnB_racing]

Originally posted by 450Rfutureracer
Thanks a lot for the advice, ending up adjusting the decomp out to .015 when the spec said .011 and it starts and runs like a gem. Im glad you found it, however with your valves with that amount of lash,
I would guess you need new valve seals, usually the seals wear if they get alot of dust entering your intake or dirty oil... change your oil and keep your filter clean and properly oiled ... im sorry to say but this is a sign of low maintenance:(

[450Rfutureracer]

Originally posted by DnB_racing
Im glad you found it, however with your valves with that amount of lash,
I would guess you need new valve seals, usually the seals wear if they get alot of dust entering your intake or dirty oil... change your oil and keep your filter clean and properly oiled ... im sorry to say but this is a sign of low maintenance:(

Yea I figure they were pretty bad, I just bought the quad used back in October and am in the process of rebuliding it. I change the oil on a regular basis and keep the filter clean and fresh oil on the KnN so it was some poor maintaince on the previous owner which sucks for me but I guess its time for valve work soon

[mikey726]

Originally posted by DnB_racing
Im glad you found it, however with your valves with that amount of lash,
I would guess you need new valve seals, usually the seals wear if they get alot of dust entering your intake or dirty oil... change your oil and keep your filter clean and properly oiled ... im sorry to say but this is a sign of low maintenance:(
Wait, I'm confused. How would excessive valve clearance make up for leaky valve seals? Or did you mean seats? If that's what you meant, I think it's more that the valve faces wear out than the seats. Dust in the intake will wear the coating off of the ti intake valves exposing the softer metal of the valve. Once that happens, the valves quickly wear out, closing up the clearance resulting in a loss of compression and hard starting. Also, he said he adjusted his decomp out to .015. If that's on top of the valve clearance, instead of the .010 plus the valve clearance the book calls for, then he raised his cranking compression which would explain the better starting. Now if his valves tighten up after one ride (mainly the intakes- the harder exhaust valves wear slower,) then I would say it's time for new valves.

[DnB_racing]

Originally posted by mikey726
Wait, I'm confused. How would excessive valve clearance make up for leaky valve seals? Or did you mean seats? If that's what you meant, I think it's more that the valve faces wear out than the seats. Dust in the intake will wear the coating off of the ti intake valves exposing the softer metal of the valve. Once that happens, the valves quickly wear out, closing up the clearance resulting in a loss of compression and hard starting. Also, he said he adjusted his decomp out to .015. If that's on top of the valve clearance, instead of the .010 plus the valve clearance the book calls for, then he raised his cranking compression which would explain the better starting. Now if his valves tighten up after one ride (mainly the intakes- the harder exhaust valves wear slower,) then I would say it's time for new valves. I meant seats. but your right, the valves are probably getting worn or cupped... either way if he cant get the desired compression with his valves in spec its a sign of work needed on the valves, possibly seats and new seals

i just wanted him to know just because he got it running that hes not out of trouble yet... I probably should have been a little more exact, but I figured he would find the all issues when he took apart, I just wanted to make the point that he still needs work, as far as what work, he will have to check everything to make sure


but he has to make sure he has done it right meaning :exhaust is .011 inch...
and decomp clearance is .010 inch ...
totaling around (.021inch)... for the right side decomp and exhaust valve.

if his total for both is .015 then he is still to tight and still needs adjustment,

but if his decomp alone is .015 and his exaust .011 equaling a total of .026 inch then he needs some sort of valve work as mentioned

[mikey726]

OK. But an increased decomp clearance doesn't mean a valve job though. The fact that he started with 30psi would indicate valve wear. Meaning the valve is "sinking" into the head, bringing the stem closer to the rocker arm, causing the decompressor to hold the exhaust valves open longer, decreasing compression. Loosening, not tightening, the decompressor arm brings the compression back up into the recommended range. And these bikes are generally known to start better on higher compression, so a little extra clearance isn't necessarily a bad thing.

[DnB_racing]

Originally posted by mikey726
OK. But an increased decomp clearance doesn't mean a valve job though. The fact that he started with 30psi would indicate valve wear. Meaning the valve is "sinking" into the head, bringing the stem closer to the rocker arm, causing the decompressor to hold the exhaust valves open longer, decreasing compression. Loosening, not tightening, the decompressor arm brings the compression back up into the recommended range. And these bikes are generally known to start better on higher compression, so a little extra clearance isn't necessarily a bad thing. you wouldn't change the valves? remind me not to buy one of your used quads lol

if they are worn enough to change clearance and just meet the minimum psi of 55 at the end of the error tolerance,I personally set mine to 63 psi, but I have duel batteries and kick backup, so I like the higher staring compression

he can go as much as .023 even up to .024 total of both and still be in range but hes at .026... good luck trying to keep that in spec

I would be worried the valves would be floating being that loose, not to mention it just wont be running to potential with less lift


if my quick math is correct he will be loosing around .15mm of lift..EDIT if its just the decompressor clearence it wouldnt affect the lift

but this is why I prefer to do leak down tests instead of compression tests, it will show so much more of what issues are present

[mikey726]

I think you're saying you think he used a compression tester to get to 55psi, and then measured the clearance, which I hadn't thought of before. But what I'm saying is that a valve won't seal any better at .015 than it will at .011. Once the rocker arm is off the valve even .001, the valve is fully seated. So if that .015 is his actual exhaust valve clearance, the only way it is going to affect compression is through loss of valve lift. But, unless he chimes in and says otherwise, I still don't think he re- shimmed his valves to raise his compression. And I think that the margain of error on the decomp spec is more for production tolerances than anything else. Meaning it should be in this range to achieve the desired compression. Kinda like the +/- on valve clearances, because it's almost impossible to get it exactly right with set shim thicknesses. I'm sure that if you or I were to measure our decomp clearance (I also have dual batteries and a kicker, set at 65psi) we would be well above the .010 called for in the book.

[DnB_racing]

Originally posted by mikey726
[B I'm sure that if you or I were to measure our decomp clearance (I also have dual batteries and a kicker, set at 65psi) we would be well above the .010 called for in the book. [/B] yes but if you or I rased it up our decompressor to have as much clearence as he has, we would probly have 70psi starting compression not 55

[mikey726]

Originally posted by DnB_racing
yes but if you or I rased it up our decompressor to have as much clearence as he has, we would probly have 70psi starting compression not 55
Just to satisfy my curiosity, and only because I already have the tank and fenders off, I just went and measured my decomp clearance. My right exhaust valve was right on at .011, and the decomp is .018. I haven't had the bike running since november and it's not running now, so I can't say for sure what the compression is, I think I set it more like 68psi. So if .008 raises compression roughly 13psi, .005 should raise it maybe 7-8, putting him at about where you are at around 63.

[450Rfutureracer]

I re-shimmed all the valves to check and the exhaust is at .011 and decomp is set at .015. I just did what I had to do to get it running for an upcoming race and going to keep an eye on it the rest of the season. I haven't done a compression test since I got it running right, so I don't know what thats at. You two clearly know more about this than myself, all I know is that it is running properly and plan on just keeping an eye on them this season.

[DnB_racing]

well at least we gave you something to think about..lol

now when you do your next valve check get a compression reading,
this will give you some idea of whats happening,
to bad you didnt get a reading after you got it running,
it gives you a sort of valve reference

[450Rfutureracer]

Originally posted by DnB_racing
well at least we gave you something to think about..lol

now when you do your next valve check get a compression reading,
this will give you some idea of whats happening,
to bad you didnt get a reading after you got it running,
it gives you a sort of valve reference

Yea you guys gave me a lot to think about and wonder, I swear sometimes my college work is easier to figure out then this stuff!!!