yz465h. no torque like i remember!

[YZ250H]

Changed the main jet on the 465 carb to the 250 carb.  That brings it up to spec with the 465G apart from the pilot (that I didn't check).  Now has new air filter - guess what - the same thing happens .
I beleive this bike still has boysen reeds - Is that my next port of call ?
Would I stick with boysen, go back to original or try the V Force (not legal on EVO I'd imagine  )

[lms6201]

i,m about to take mine out , i ,ve changed the reeds back to steel , i think the fiber reeds become fatigued and get a bit flappy , i,ll let u know

[lms6201]

yep the std reeds worked for me ,

[YZ250H]

I'll give it a go and see what happens - hopefully the same as you 
Where would I get such a thing - the local Mr Yamaha ?

[lms6201]

 yep ,yamaha , if boisen,s have been fitted , the std reed stops are removed , so u would have to get those as well , if u don,t have a set ,  perhap,s  just a new set of boisen,s ?    i think one of the dt 400,s had an 8 petal block which fits , makes it a bit snappier i,ve heard , something i probably won,t get around to trying , would like to hear from someone who has   

[YZ250H]

You've just made a decision for me.  Thanks.  I think it has boyeson's fitted so I won't be fitting the standards as I assume the reed stops are removed.  Interesting as the reed block I have from the 250 has fibreglass reeds and the stops are still fitted 
I was going to start a new thread in tech talk about the benefits of the boysens, but now that is academic 

[Marc.com]

well thats my guess down the toilet, but at least we eliminated the carb. Sounds like something started leaking or gradually breaking down over time...... back to the reeds and electrics I guess, crank seals ??

[Marc.com]

run it with the gas cap off.... fuel filter ?

[YZ250H]

For the dollars it's worth a try - I'll get a different one.
Fit new reeds on the week-end.

Come in Rusty - any more ideas ??

[lms6201]

what,s the std gearing for 465 ? 14 to 46 ?  i,ve got a 15 on the frount , reckn it was pulling well over 160  but bogging down a bit , also is the rear hub different from g to h 

[holeshot buddy]

14 / 48 gearing is fine
carby you will need a 4.5 slide 390 main 55 pilot
 fit your reeds and try
make sure float is not to high
if still no good
take off stator cover mark tdc on flywheel and case
set timing to specs i cant remember exact but get a dial guage
and set it btdc at right distance and mark case
get a battery and timing light start her up
check mark while engine running should be fluctuating at tdc at about 2000rpm approx
increase revs it should advance then as the revs increase a lot more it will retard slightly
this will tell you if your cdi is working ok
otherwise advance your timing plate about 2.0 mm
should be clockwise
these bikes are bulletproof and once they are set up
you can leave them alone for a long time
my 465 was one of the quickest in qld
it had dg pipe and muff
boost bottle, standard ports
was just set up good
cdi should be ok they are very reliable on 465s
not and air leak
does it have too many base or head gaskets some people put them in
to tame them down
try the timing and ride it you can always turn it back
keep me posted would like to know

cheers rusty

[YZ250H]

No sweat - thanks Rusty.  I will gradually work through that list and order the parts today.

[Kane Mcguire]

hi yz250h kane here. if the bike ran great previously then do not try different jetting. jets dont change all of a sudden! something has failed mechanically. if the bike runs good when you turn off the fuel tap (leaning out the mixture) then that rules out ignition problems.  i would be trying needle and seat and the float level and also making sure the floats are not bent and rubbing the side of the carb bowl. also that the main jet hasnt fallen out etc. it has new boyesen reeds. but check they are sitting flat and not broken.  contrary to the opinion of many in this forum i have never had trouble with boyesens. over the last 20 years, fitting a set is the first thing i have done to every bike. always gives more bottom end and makes them rev cleaner. one more thing, i wish i still owned it!

[YZ250H]

Gidday Kane,

Mate, it seems like we think alike.  That's the reason I posted on here.  In that last 12 months trying to get a 125H motor going I have learnt a bit and thought it was very odd that it should deteriorate over just a couple of hours.
Full credit to Rusty and everyone else for the advice.  These are all things I will add to the list for checking.  I guess that is what this thing is all about - sharing lessons learnt.

The key for me is that once I got it started wehn I first got it home (thanks for the excellent advice - I continue to use it) it went like the clappers (as you can attest).

Something I haven't stated on here already is that it won't just start straight up.  I have worked out I need to kick it a few times with the plug in, pull the plug out and kick it by hand a few times.  When  you kick it then it will fire first time every time.

I have not pulled the reeds out yet.  Hopefully I can use them for the 250 if they are still good on the 465.

I will try a few things next week-end and see how we go.  I have ordered new jets to take her back to standard.  Should it be altered for boysens ?  By the time I'm finished I should have new air filter, all new jets and new reeds - wtf else could it be ?

Sorry mate - she will probably be with me till I kick the bucket now    I've got a bit of a tart up planned for her later on - similar standard to the 250.

thanks for chiming in.  I will keep reporting back

[lms6201]

 kane , i hope u didn,t read into any of my posts and get the idea i didn,t like boisen reeds , that,s not the case , but it seems they do need to be kept fresh , for me the steel ones  , i have on hand , are easier to live with , i,d like to give the dt400 ones a go , but am unsure which model fits