CRF450 hard to start

[morg_nz]

Replaced the intake valves (with a stainless kit) on my 03 crf450 late last year. I was pretty confident that I got the clearances right and the timing lined up good. Took it out for a ride and noticed two things:

1. When i kick it over, i gently kick until i feel resistance (i.e. when it is getting close to tdc) then go back to the top and give it a full stroke to start. This was not a big deal before i did the valves but since when i get to TDC i have to put all my weight on the kick start lever to get it to roll past TDC (to the point it feels like i'll almost break the lever) but then the rest of the stroke feels fine and it starts ok

2. When i was out riding however i was having a fair amount of trouble starting the bike - like 10 - 15min each time i stalled it. i never had that issue before doing the valves - it would usually start 1st or 2nd kick when hot with the hot start pulled in

does anyone have any ideas what might be causing these issues - particuarlly why it is so hard to kick past TDC?

thanks in advance

[FJRider]

With the valves done ... and closing properly ... the compression will be raised. Thus seem more difficult to get past TDC ...

Kick it like you mean it ... or it will kick you (over the bars)

My thoughts anyway ...

[morg_nz]

With the valves done ... and closing properly ... the compression will be raised. Thus seem more difficult to get past TDC ...

Kick it like you mean it ... or it will kick you (over the bars)

My thoughts anyway ...

yeah thats what i thought - and i've also heard that the springs are harder to match the heavier stainless valves - but even so im literally putting all my weight to get past tdc and i can hear the lever groan like its about to break

[FJRider]

yeah thats what i thought - and i've also heard that the springs are harder to match the heavier stainless valves - but even so im literally putting all my weight to get past tdc and i can hear the lever groan like its about to break

EAT MORE PIE'S ... :innocent: :killingme

[barty5]

recheck your timing and clearances for a start

[morg_nz]

recheck your timing and clearances for a start

yeah thats what i am intending to do - just thought i'd see if there is anything else that may be causing it that would be worth checking

[TrentNz]

kick it over like you're stomping some cunt in the head :woohoo:

[Katman]

I believe around the 2003/2004 period there was a batch of CRF450s that had the cam sprocket timing mark poorly positioned.

It's possible it's a tooth out.

[morg_nz]

I believe around the 2003/2004 period there was a batch of CRF450s that had the cam sprocket timing mark poorly positioned.

It's possible it's a tooth out.

if its a tooth out which way would i turn it - towards the lobe or away from it?

[Adriaan]

Interesting. I'm having the same issue with my 2008 crf450r. The valves have also just been done and they are stainless too.

Also, when i first got it. The kickstart wouldn't move AT ALL. I had to put in gear and move it back and forth to move the piston enough to be able to kick it over.

Hasn't done it since, but I'm having the same issue when i try to kick it when it's been running. Sometimes it takes 10 mins at least.

[Pornstar]

It shouldnt be that hard to kick over, also check your auto de-comp, it may not be opening enuff, your gunna break the kick starter stuff at that rate.

[morg_nz]

It shouldnt be that hard to kick over, also check your auto de-comp, it may not be opening enuff, your gunna break the kick starter stuff at that rate.

yeah it never used to be this hard - in fact when i bought it i was quite surprised as im not that tall (168cm) and thought i might struggle a bit to start it but never had any problems till now.

cheers i'll add auto decomp to the list

[TrentNz]

drop a comment on this page - http://www.facebook.com/TracktionNZ (their a motorbike shop)
saying what the problem is and if they know what it is/why its doing it.

[Pornstar]

I used to have an 05 Crf 450, I set the de-comp a smidge tighter than standard, this gave a little more comp when kickin it which aided the fire up.

[barty5]

It shouldnt be that hard to kick over, also check your auto de-comp, it may not be opening enuff, your gunna break the kick starter stuff at that rate.

Good point I hadn't thought of the fact they have an adjustable de-comp which I doubt any one checks very often.

[morg_nz]

yeah it was the timing - like was said it was out by one tooth. i can see how i made the mistake too as you only have to be looking at it from slightly the wrong angle for it to be out. started easily, 2nd kick and was quite easy to kick over (like before)

cheers

[CRF119]

What normally happens if you time it about right then you insert tensioner. That drags the timing about by a tooth. I did this on my CRF450R8 had me confused for a while. Also did it on a cam belt on a Lexus V8 once it really had me confused!

So what i do now is once i think ive got it timed right and the tensioner is in and set i kick it over a few times to make sure it all lines up again.

[TrentNz]

oh at-least it was a relatively easy fix then

[morg_nz]

oh at-least it was a relatively easy fix then

yeah pretty easy - only problem is the bloody 6mm bolts holding the rocker cover on - i think i may have stripped one as i was putting it back on and it may only be just hanging on. i'll give it a bit of a run tomorrow and see how it holds but i'll prob have to helicoil it next time i have the head off. grrr.

[barty5]

yeah pretty easy - only problem is the bloody 6mm bolts holding the rocker cover on - i think i may have stripped one as i was putting it back on and it may only be just hanging on. i'll give it a bit of a run tomorrow and see how it holds but i'll prob have to helicoil it next time i have the head off. grrr.

pull it out measure bolt and see how long it is and check how deep the hole is normally youll find the thread is deeper then just find bolt to match the depth.

[CRF119]

The Honda bolts are a special stepped bolt so you can't over tighten. Takes a bit to learn the trick of lining the buggers up tho.