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Discussion Starter #1
setting my pilot screws and noted they were wound out quite a bit. Seems to be some discrepancy around what the right number of turns are?

1/2 or 1 1/2 turns? also the factory setting says 1/2 turn back? does this mean wind screws out fully then turn back 1/2 or wind in fully and 1/2 out?
 

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To figure out how many turns you are out, first you need to turn it in all the way and seat it very lightly.
If you turn it in to hard, you will hurt the carburetor body. If the manual calls for 1/2 of turn out. I would start with around 3/4 of a turn out. If the book calls for a half a turn out that is just a starting point. Once you get it started, and warmed up, you should adjust them in or out to find the highest idle.
To adjust, it needs to half ass idle.
Adjust the pilot screws one at a time. I start out by just going out a half a turn and listening for 2 or 3 seconds and see if the motor speeds up or slows down. If you turn it out, and it speeds up, then you need to go out another half a turn and see if it speeds up.
Then I turn the idle back down. Then I would turn it out another half turn, and if it did not speed up I would go back a half a turn, ( the highest idle).
Do the other three the same way.
And you should not have to go more than three and a half for four turns.
If it still speeds up after 4 turns you probably need a bigger pilot jet.
( you should synchronize them also)
Have a good one ???
 

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Discussion Starter #3
To figure out how many turns you are out, first you need to turn it in all the way and seat it very lightly.
If you turn it in to hard, you will hurt the carburetor body. If the manual calls for 1/2 of turn out. I would start with around 3/4 of a turn out. If the book calls for a half a turn out that is just a starting point. Once you get it started, and warmed up, you should adjust them in or out to find the highest idle.
To adjust, it needs to half ass idle.
Adjust the pilot screws one at a time. I start out by just going out a half a turn and listening for 2 or 3 seconds and see if the motor speeds up or slows down. If you turn it out, and it speeds up, then you need to go out another half a turn and see if it speeds up.
Then I turn the idle back down. Then I would turn it out another half turn, and if it did not speed up I would go back a half a turn, ( the highest idle).
Do the other three the same way.
And you should not have to go more than three and a half for four turns.
If it still speeds up after 4 turns you probably need a bigger pilot jet.
( you should synchronize them also)
Have a good one ???
thanks mate,

I am at 2 full turns out and its hanging on idle. When I was at 1/2 turn it coughed and spluttered a lot. The orig reason for the adjustment was because it hesitates/stumbles at around 7-8000rpms and wasn't revving cleanly to redline
 

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Discussion Starter #4
thanks mate,

I am at 2 full turns out and its hanging on idle. When I was at 1/2 turn it coughed and spluttered a lot. The orig reason for the adjustment was because it hesitates/stumbles at around 7-8000rpms and wasn't revving cleanly to redline
worth noting the bike is totally stock airbox/exhaust etc...
 

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The pilot screw, is the adjustment for the leanest and richness of how much gas comes out at low RPM. The pilot screw make a big difference at a idle but at seven or eight thousand RPM they make very little difference. I would guess it's like one or two percent difference at higher RPM.
For the trouble at higher RPM I would check for leaks between the head and the carburetor, and the carburetor and the air box. and make sure the airbox was not leaking someplace extra or missing the air filter.
Have a good one ???
 

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Discussion Starter #6
so all back together and running heaps better! It does still have a slight hesitation as you hit circa 7000rpms and almost intermittent? starting to think maybe plugs or coils. once it catches its off again all the way to redline
 

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If your airbox checks out okay and not leaking and has the air filter in it I would try to put some duct tape on the airbox Inlet air hole and cover maybe 20 30% and go try it. If it don't help you can take the tape back off.
If this helps your flat spot, probably means you are too lean in the mid-range, to fix that you would need to raise the mid-range needles, a 20 thousands washers worth.(maybe)
Stay safe out there hope this helps you.???
 

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Discussion Starter #8
will give it a go, I did raise the needles one notch - while it seems a bit better overall the fumble or hesitation is still noticeable. Its quite sudden/jerky when it hits this point in the rev range which got me thinking about plugs/coils. Can't hurt to change plugs once I can get some
 

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have you checked the valve clearances? if you spend a day or two reading the forum ;-) some people have had good results with re torqueing the head.
does it have a flat spot though the rev range at 1/2 or 3/4 throttle?
one of the things that gets over looked is the needle jets, they wear oval, as you will find with the rest of the carbs (they are old), the VM29ss carbs are harder to tune than the CV type carbs.
 

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Discussion Starter #10
Cheers Pete, yep carbs are in really good condition no oval needle jets.

I haven’t looked at valve clearances and when I do I’ll check head torque.

will change plugs anyway as I’m not sure how old they are. It’s pretty close to being right just a bit more fettling....
 

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How to check your spark? I have in the past strapped a timing light to the bike and drive it down the road if it cuts out because of spark you will see the timing light go off when it starts cutting out.???
 

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Discussion Starter #12
Finally sorted. It’s running a foam filter which is breathing a little more than the stock jet/needle settings
 

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Discussion Starter #13
Also, decided I’m going to try and find a J K or L model. I originally set out to get one but couldn’t pass up on this survivor as it was too original. Would consider a trade if anyone has one
 
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