89 xr-4 150 black max reed advice

ibehm

Cadet
Joined
Jun 26, 2012
Messages
7
i have been dealing with an issue of rough idle/ having to raise idle speed to stop from stalling. Have done a link and sync changed plugs, checked spark to see if firing on all cylinders. Still idling rough and noticed plugs always look wet when i check them. Removed carbs and inspected reeds and the all look good by eye, very little gap but they are the stock steel reeds. I was wondering if a set of aftermarket reeds would be worth installing. Also what could cause the motor to run so rich in idle? Everywhere else the motor seems to run good and will rev fairly easily to 6000 rpm.
 

1nebel0

Chief Petty Officer
Joined
Nov 28, 2005
Messages
512
Re: 89 xr-4 150 black max reed advice

When you adjusted the idle speed did you do it with idle timing as this is how it must be done...you then need to check floats and carbs as it most likely is a fuel problem given what you have indicated above.
 

ibehm

Cadet
Joined
Jun 26, 2012
Messages
7
Re: 89 xr-4 150 black max reed advice

I have not went through carbs yet but they are off now. The seloc manual says for my model year there is no idle running timing number but adjust timing 24btdc wot and 22atdc at idle with screw all way down. For other years it says 3-11 atdc running at idle but i was not aware that you should not adjust the idle screw for carbs it does not say that in my manual.
 

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,590
Re: 89 xr-4 150 black max reed advice

Also what could cause the motor to run so rich in idle?
Reeds cannot make one run rich... float levels off or heavy, needle and seats weeping under fuel pressure ,incorrect adjust of carbs if adjustable, clogged recirculation valves and timing will make one run rich at idle.
 
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