PitsterPro XTR 150?

[low_rb]

Ive reset the tensioner every time.

With the original chain it diddnt even touch the chain slider at full extention.

With the first chain i brought it was useless as it was that tight i diddnt bother putting the spring in the tensioner

With the dhz chain its looser that the original to the point it would throw the chain off the crank sprocket when the cam would rock over when turning the flywheel by hand.

DHZ said i should have about 3mm from the piston to the top of the bore i measured that from the edge of the piston and its 2mm.
Also if i hold the head and look at it level the inlet valve sticks out slightly above the combustion chamber is that normal with these heads?

 

[low_rb]

Ive got a #40 pilot in now. No change to the spluttering.
Moved the clip up and down one and no real change with either position.
Mixture screw dont make alot of difference either.

Its far more rideable than it was but the revs need to be kept up

 

[my67xr]

How many turn's out have you got the mixture screw adjusted to with the #40 pilot ?
Can you put up a pic of the cam sprocket too please ?

 

[low_rb]

Well ive settled on this jetting for now.

#40 pilot
#100 main
Clip in the top slot
1 1/4 turns out.
Runs pretty good now but i think ill try a #95 main


Ill get the sprocket pic later

 

[my67xr]

rotn50 ran a #98 in his OKO 26 on a Z160HO from memory, but i think he had a smaller pilot too?

 

[low_rb]

No worries. Ill keep playing but im on the right track with that atleast.


Heres the cam sprocket

 

[my67xr]

Ok, all i can think of is worn out chain rail's/guides

Found another pic showing my stretched timing chain compared to the new one (bottom)

 

[low_rb]

Slides would be worn. I diddnt think they looked that bad but comparing to those pics they are.
Ill see ify local shop can get some i cant find any on the net.

 

[my67xr]

You'll need to take the flywheel off to swap the top one over, then remove the stator and there is a screw holding the slide/guide to the engine case, don't overtighten the screw when refitting the new guide or the case can crack

 

[low_rb]

I know how to get them out, ive had to remove the bottom one as it was in crooked when i got the bike.

Got new ones on the way, hopefully it will sort this overly slack chain issue

 

[low_rb]

Ive also got a #98 main coming with the sliders.

While running around to see if i could get a jet in town one of the places told me i might be better to go with a leaner needle.

Ever played around with different needle's?

 

[my67xr]

With the spluttering, what rev range is it doing it?
Have you checked it for any vacuum leak's?

Start it and let it warm up a bit, then spray degreaser/carby cleaner, wd40 etc on all the join's from carby to adapter, adapter to manifold, manifold to head
If while spraying the join's you hear the engine rev's change at all, then there is a leak there that'll need to be fixed.
Sometime's the rubber/alloy adapter can warp a little and let air in, if this happen's take it off, pop the o'ring out and rub the flat adapter moutning face across some 180grit sandpaper on a hard sanding block.
You might be able to square up the mounting face again.
If that doesn't work then you might need to make up a thick paper gasket and fit between the adapter and manifold (leave the o'ring out too)
The paper gasket trick will seal better than the o'ring and there's less chance of warping the mounting face too.

The cable tube/guide on the OKO where the cable goes into the top can be another spot they'll suck air.
If you haven't got a rubber tube to seal them you can swap one off an old throttle cable onto your OKO cable to make sure it cant suck air there.


If there are no vacuum leak's.
With the mixture screw at 1.25 turn's out, i would be upping the Pilot jet to a #42
Then when you retune it, the mixture screw will end up being about 1.75 to 2 turn's out.
Main jetting i would have thought a #102
The JJH needle (stock) is the perfect size, and just set the clip on the middle notch when you're trying it out with any new jetting, may need to raise it one to the second notch from the top if anything

If it's idling too low turn the idle speed screw in a touch.

Tuning it,
do you wanm it up first, then raise the idle speed to about 800rpm's, then adjust the mixture screw ?
Once it's adjusted right the engine will be running at it's highest/smoothest rpm, then just turn the idle speed screw back out till it idle's at a nice rpm again

Try it out from there, if the mixture screw need's adjusting it'll only be a slight turn to the left or right from there (1-2mm either way)

Once the pilot jetting is sweet, give the bike a decent run in 3rd or 4th for 10/20 second's held at wot (slight incline if possible)
Then hit the kill switch (while holding the throttle wide open), pull in the clutch and bring the bike to a stop.
Get off and pull the spark plug out and check the colour of the porcelain near the tip.

Take note on how strong the bike feel's up through the gear's and rev range.
Note where the engine run's funny and at what throttle opening eg; stutter's at 3/4 throttle and then come's good at wot.
Let us know and we can advise you from there :thumbup:

 

[low_rb]

Theres no vacume leakes.

Problem is around 1/4 throttle

Every time i change a jet i put the clip in the middle slot.
Only improvements have ever come from leaning it out with the main jet and/or dropping the needle

It is slightly sparitic though as a few times its pulled clean all the way, if it does splutter once its past it and the revs are up it pulls well.

Dont have enough room to run it at WOT for that long, 2nd i might get 10seconds


I finaly found my cable to charge the Gopro so heres a little edit of the problem, how it goes after i get past it and idle.
I have exagerated the issue buy going slow around that corner so i could load it more going up the hill.

LXR miss - YouTube

 

[my67xr]

Almost sound's like the Pilot jet is too big ?
When you blip rev it from idle, it rev's clean ?

What jet's do you have for it atm ?

 

[low_rb]

Some times it will rev clean but mostly it will bog a little.

Jets i have
Main #100, #105 and should have a #98 tomorrow
Pilot #35,#36,#40

also i noticed today that from cold it wont start with the choke on. and even once running but still cold it will die if i touch the choke

 

[my67xr]

Yeah that's how mine is set up pilot wise, don't need choke.
Try turning the mixture screw out to 1.75 turn's (another half turn form where it currently is)
Have you tried it with the #40 pilot and the 100 main ?
If you do and it feel's a little flat up top then i'd fit a #102 main

 

[low_rb]

ive been playing with the mixture it between 1.5 and 1.75, seems to be the best spot at the moment.

#40 pilot and #100 main are in it now

 

[low_rb]

Got the timing chain guides today, mine were worn a bit.
new one on the left


Stuffed with the jetting a bit.
Tried the #36 pilot with the #100 main and would barely idle. So i just went back to where it was yesterday.

Just got that annoying dead spot if i snap it open but it dosn't do it all the time

 

[low_rb]

Well this has hardly been touched since my last post. The boy hasnt been all that intrested in it.

got it going today and im wondering if the valves may be partly the cause for this dead spot off idel.
i diddnt have a chance to check the gap but it was spot on last time i was working on the bike
had the air filter off after i cleaned the carb out and a couple times during my buggerising around i noticed id get a backfire and slight flame back out of the carb.

switched to the #36 pilot and it got worse

 

[gottagetacheaperhobby]

So the 40 is to rich, and the 36 to lean? Grab a 38 then...

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