www.gpz-305.de

Rey · Verfasst am: So Jan 27, 2008 2:22 pm Titel: gpz305 i havnt a clue what is wrong

my gpz that i am restoring still has problems the idle speed is perfect but when i go to rev the engine the engine doesnt pick up like there is no fuel coming out the main jet bothe pistons are lifting and when choke is applyed the engine will rev fine.
i unscrewd the main jet 1 turn on bothe carbs and ran the engine but it started to run perfect but when i took the float bowl of the 2 main jets were still in place but completly unscrewed but the engine aws running fine both main jets a re clean and ahve 95 stamped on them please help thanks

Lothi · Verfasst am: So Jan 27, 2008 7:28 pm Titel:

Hi Rey

The main jets are for full speed and only for that!
Up to 1/4 only idle-system is working.
1/4 - 3/4 the pilot-system is working
from 1/2- 3/4 the main-jet begins to "work"
3/4 - full only the main-jet system is working

--> If the engine doesn't rev up due carb-problems ist is either the idle- or the pilot system, neither the main-jet-system !

But please consider:
Mostly Your fault happens if carbs are out of sync !
This bike is very, very sensitve to that!

Please check:

1) Do a rough check if the same happens on both cylinders; let engine run on one cylinder and then on the other. If it is the same behaviour, then there is a common mistake; look here: http://www.lothi.org/forum/gpz-305/viewtopic.php?t=777

2) Check the pilot and idle-system; especially the small holes here: http://www.lothi.org/forum/gpz-305/album_page.php?pic_id=66
Try to follow-up the way the air is going through. Hint: one ends up at here; labled "Nebendüse":
http://www.lothi.org/forum/gpz-305/album_page.php?pic_id=68
the other where the screwdriver is (idle-mixture)
http://www.lothi.org/forum/gpz-305/album_page.php?pic_id=82

Check also the micro-holes; one bigger right side and 3 !! micro-ones left side:
http://www.lothi.org/forum/gpz-305/album_page.php?pic_id=81

3) check the pilot-jet beneath the main-jet: all holes of the jet-tube must be clear, the same for the main-jet !
check also the pilot-needle: the tip must not be deformed !

4) Check pilot-screw: softly screw it up to the end (very carefully, do not destroy the tip of the needle) and turn it up exactly from there 1.5 turns !

5) Also check if it revs up better if side-stand is out and in. This is also a typically fault for this bike...

And least: Are You testing with warmed-up engine or with a cold one ?
Typically beginners fault for this bike: If engine is cold ist doesn't run nor rev up without choke !

You need at least at temperature of january outside a minimum of 5-10 minutes warming-up the engine running at idle-speed or 2-3 km traveling before You can switch-off choke; otherwise it doesn't rev up !
_________________
Grüsse

Lothi tach