carby problems 07 pampera 450

[Pampera]

Hi , 1st time on here . I bought an 07 pampera 450 , 6 weeks ago . its only got 4500 km on clock. It has a bit of a miss ( stutter ) in the low to mid range , when not under a lot of load , starts well , idles well , great hard thru the gears and top end . the local honda shop said it was running a bit lean and ordered a 140 main jet from a 138 std . theold plug was a brown colour which I thought was ok . Anyway they changed it over and its no different . Two people have since said it shouldnt be main jet , more like needle seat height or possible pilot jet .
Anyone had similar problems , just want an easy fix . Dont want to mess with carby too much and wreck the rest of the range . has a phf 36 dellorto carb.

[lankydoug]

Originally Posted by Pampera

Hi , 1st time on here . I bought an 07 pampera 450 , 6 weeks ago . its only got 4500 km on clock. It has a bit of a miss ( stutter ) in the low to mid range , when not under a lot of load , starts well , idles well , great hard thru the gears and top end . the local honda shop said it was running a bit lean and ordered a 140 main jet from a 138 std . theold plug was a brown colour which I thought was ok . Anyway they changed it over and its no different . Two people have since said it shouldnt be main jet , more like needle seat height or possible pilot jet .
Anyone had similar problems , just want an easy fix . Dont want to mess with carby too much and wreck the rest of the range . has a phf 36 dellorto carb.

Low to mid range will be needle or pilot. A easy and free thing to try is raise the needle one notch and see if it helps.

[Qui-gon]

Looks like an FCR carb to me or a chinese copy? If it stumbles of the bottom check the accelerator pump adjustment (if it has one) because it is probably getting to much fuel as you open the throttle. Had same problem with an early WR450. If can reduce the "squirt" a bit it will help I think. Can't believe where the diagnosis process must have started from to end up with the solution being the main jet!!!!

[Pampera]

Yes a mate of mine, said shouldnt be main jet , try needle clip up or down . now the thing is how easy is it . I know old style carbs are easy , but is something going to spring out and not go back in or do I go back to the bike shop and hope they do it properly.

[Pampera]

It has a PHF 36 dellorto carby , I did ring a gas gas agent , he wasnt real sure of the problem but did say the pumper carb may be pushing too much fuel in and to look at pilot jet and needle and seat . I dont think there is any adjustment on the pump . Im a bit annoyed with Honda shop , saying new main jet would fix it , seems you have to work things out and do them yourself these days , no one cares much , they just keep telling you to come back for more money !

[Qui-gon]

I think you will find the amount pumped in is fixed. It is usually the timing of the pump which is wrong. To early will give you the off-idle stutter

[Pampera]

So is there a way to adjust the timing of the pump. now it has the miss anywhere from 3000- 5000 rpm and its not predictable , sometimes does it more than others , and its more noticeable about 4500- 5000 rpm , like when riding in about 3rd gear doing about 60kmh. and not under much load .
Guess i will try needle clip first , and check pilot jet , make sure its clean . a little worried about what the guy did to it before me . He has since told me he took the starter cover off instead of the oil filter cover when he first got it and didnt put it back on right and ended up breaking down and had to get bike shop to pick him up !!!! he said that was the only thing that went wrong , but who knows !

[OLD.IT]

mine stalls off idle if i crack the throttle. and i found if i lift the needle it runs rough at all revs but if i drop the needle it runs mint and doesnt stall as easy.
im am going to put a fcr on it cos shops wont touch the dellorto

[stainlesscycle]

Originally Posted by Pampera

So is there a way to adjust the timing of the pump. now it has the miss anywhere from 3000- 5000 rpm and its not predictable , sometimes does it more than others , and its more noticeable about 4500- 5000 rpm , like when riding in about 3rd gear doing about 60kmh. and not under much load .
Guess i will try needle clip first , and check pilot jet , make sure its clean . a little worried about what the guy did to it before me . He has since told me he took the starter cover off instead of the oil filter cover when he first got it and didnt put it back on right and ended up breaking down and had to get bike shop to pick him up !!!! he said that was the only thing that went wrong , but who knows !

the phf pump operates off the slot in the slide. you could change the timing by choosing a different pump slide cam. you can adjust the volume of the pump with the screw on the backside. you can adjust the velocity/delivery of the fuel with the pump jet.



see page 17 in this link

http://www.morinispecial.it/manuali/...ning_guide.pdf


all parts are available in the usa through herdan. the phf is a great carburetor. many shops won't touch them because they are unfamiliar with them. the phf/phm have been around since the 70's...

[Pampera]

Ok , thanks for all the replys . will have a look at needle first and if its not that, look at other options going from easyest to hardest . And if I cant fix I might off load it , Its still perfect for hard work in the bush for some young guy. I seem to be using it more on the tar than the dirt at the moment and thats when it does it . they really are a dirt bike and just want to go hard.