question on timing

[spec]

OK, so we put a new piston my my ltr, and put it back together. when I go to start it it has a hard time starting, once it finally starts, it doesnt seem to want to idle decent, and then when driving it about half throttle in every gear it seems to sputter. so I parked it. I went to double check the timing tonight, and I think we may be one tooth off on the exhaust cam. Would being one tooth off cause such problems? also checked my vavles, intake seems good. but for exhaust they say .20-.30 for clearance, I cant even get a .20 feeler in there tho... Idk if that would be caused from being a tooth off? I have checked my fuel filter and stuff like that. I dont think it is anything with the fuel line, but I could be wrong. Just looking for some peoples input before I decide to do anything. If it sounds like just a timing issue I can fix that( which i plan to move the exhaust cam forward one tooth anyways) But was just wondering if anyone else had ran into this issue, and had any other ideas on what could be the problem. Hopefully its just that being off one or two teeth that is causing it. :ermm:

[leasureryan]

first off, you shouldn't even have capped it knowing the valves were out of spec. (or not knowing, however you want to look at it)

second, yes, it will run like **** if you are one tooth off. sounds to me like you need a service manual, and follow it step by step, or let someone else more qualified do it. what was the torque spec on your cam caps? I'm guessing if it's out of time, and the valves weren't checked, that the cam towers have also been over torqued. just a few basic observations

2 teeth off and you will most likely bend a valve or shove it through your piston

[kfx400rider03]

Sounds like u over tightens the cam holders. I did it once before and used a lapping compound to fix it. The cam caps don't need to be tight at all just snug

[Springbok]

Come on guys,play nicely-all of us want to try different things and work on our own things-it is just a manly thing.

Surely it can be the timing.If you have the timing way off you might also have a problem checking the clearance. Make sure the low end of the cam is on the bottom when checking clearance. Just re-do your timing and try again. I am sure you wont make the same mistake again. Keep on going!

[spec]

thats exactly it springbok, I know I screwed up my timing, and admitt that. Now I would like to learn from my mistake and correct it. I would much rather learn how to do these things correctly the first time myself, instead of having to take it in and pay someone $75 an hour for something that seems simple. Not trying to start anything with anyone that posted replies here. Thankyou for the info. I talked to someone at the local shop we have here also, and he said pretty much everything you guys told me. So again thankyou for the input, and hopefully I'll have it back together and ripping within a few days.

[Drewltr450]

Turn engine to top dead center, There are little punch marks near the teeth of each cam. the dots for the intake should line up with the top of the head at 3 o'clock and then the other at 12. Exhaust 9 o'clock and 12 then your timing will be perfect.

[kfx400rider03]

Originally posted by Drewltr450
Turn engine to top dead center, There are little punch marks near the teeth of each cam. the dots for the intake should line up with the top of the head at 3 o'clock and then the other at 12. Exhaust 9 o'clock and 12 then your timing will be perfect.
exaclty. just to doube check it is correct to is to cound the number of pins from the 12 o clock dot on the intake cam to the 12 o clock mark on the exhaust cam there should be 15 pins including the ones right above the dots

[tmatthews4]

good info guys,not trying to steal the thread but got a similar question,if you go from stock to an atp cam will the procedure for the timing marks stay the same and will the shims be different

[kfx400rider03]

idk about the atp cam or if there are the dots on the cam sproket. and you only need to change your shims when they are not with in specs. (.004-.007 i think) if the atp cam doesnt have the dots if it is a intake cam wmake the lobes point at 10 oclock and if its a exhaust cam they have to be towards 2oclock

[tmatthews4]

they have the marks ,i dont think they do anything to the sprockets,just the lobes,and it is intake only,thanks for the help

[kfx400rider03]

ok sence there are dot on the cam sprokets then it would install the same way as a stock cam.
btw what atp cam did you get?
and what other mods you have?
im thinkg of getting a cam and hi comp piston

[tmatthews4]

not sure what size it is,i bought it off a guy,the lobes are about 3/32 over stock,im going with athena 500 bb,atp pp head,+1 exhaust valves,dasa pipe,fuel atv intake,and cherry bomb,also just got a pc5 with autotune, hope it all works out,dont have it back together yet,i think ill take it to someone who knows about shiming the valves,i dont want to screw it up,just dont know enough about the valve settings and timeing with the different cam,

[kfx400rider03]

it not hard to do but i watched my buddy do it and thats how i learned. \you just need some one to show you first and you will beable to do it your self
nice mod list too