symptoms of worn out idle needles

[cambosoup99]

I'm looking to overhaul my carbs upon inspection I found that all 3 idle needles had worn in grooves at the tips. Manual says to replace if grooves are present so parts are on order.

would worn idle needles cause the problems that i was having like.

1. sometimes when i start the motor it idles but when i give it throttle it cuts out.

motor is an 85hp force 1988

on a side note before working on the carbs.

I replaced fuel pump diaphram, fuel lines, spark plugs, new battery, added fuel water separator (after replacing the parts it did start up alot easier) but still having the problem above.

what are your thoughts. do you think the idle needle will solve the problem.

thanks

 

[pnwboat]

Re: symptoms of worn out idle needles

Groves in the idle mixture screw tips certainly doesn't help. Stalling problems are a common complaint.

Make sure your carbs are in "sync". The maintenance manual explains this procedure.

To minimize stalling, make sure the minimum RPM's while in gear is around 700 RPM's.

Adjustment of the idle mixture is also critical. Make your initial mixture adjustments for best running while in neutral. Open the throttle plates quickly to wide open. If the motor dies, richen the mixture 1/8 of a turn. Let the motor run like this for a minute and repeat until the motor no longer dies.

If the motors kind of loads up, or hesitates when when you blip the throttle to wide open, then the mixture may be too rich. Lean out the mixture 1/8 of a turn and repeat until the motor rev's without hesitation.

This should get you pretty close to optimal adjustment.

The final test will be out on the water with the motor under a load. Pay close attention to minimum RPM's in gear. You may have to tweak the RPM's and mixture a bit, but you should be pretty close.

 

[cambosoup99]

Re: symptoms of worn out idle needles

thanks,

 

[cambosoup99]

Re: symptoms of worn out idle needles

I thought id post an update to my carb overhaul.

I got all the parts cleaned, replaced all the needles, gaskets, springs, etc and put it back together today.

Installed it, and it fired right up

seemed to be idling high though. around 1000 - 1500 rpms. But 1000rpms is what it was idling at before.

I have the needles set to 1 1/4 turns out from lightly seated as per the manual. it looks to be on the rich side from all the white smoke that spewed out the exhaust. but i'll have to get it in the water this friday to do somemore adjustments.

overall seems to be running considering this is my first carburetor overhaul.

hopefully when i get in the water. I can get the idle adjusted to 750rpms as per the manual. ALSO WHERE IS THE idle speed adjustment screw the book says its on the towershaft. can someone show me a pic of it. (dont get it confused with the idle mixture screw.. the one in the carb)

 

[cambosoup99]

Re: symptoms of worn out idle needles

ok i found the idle speed screw its on the back of the towershaft with another nut to lock it in place.

 

[pnwboat]

Re: symptoms of worn out idle needles

Sounds like you're on the right track. Real test will be out on the water.

 

[cambosoup99]

Re: symptoms of worn out idle needles

I got it in the water, and the idle seems to be good but its still high around 1k-2k. but when i put it in gear it drops to around 700 - 800. My question is...

Idle supposed to be high in neutral? If i adjust it in neutral will it affect my idle in gear? Because in gear its sits around 700-800 rpm.

Took it out wot and it doesnt seem to get to the full rpms like before i did the carb rebuild. it would go up to 3k rpm and not any further.

could this be a timing issue now?


by the way.. the carb overhaul did fix my stalling issue i was having before. it doesn't shut off anymore when i go to put it in gear. but now i have a new issue. dang... maybe i should start looking for a new motor.

 

[cambosoup99]

Re: symptoms of worn out idle needles

ok i adjusted my idle in neutral when i was in the water today.

I got the idle down to 700-800 range. I notice there was some play in the linkage. on the tower shaft. i could move it maybe 1/4" forward and back. so it was a lil difficult to get adjusted and when i got it adjusted it would somehow still rev up and down by itself.

then i tried to turn the idle mix screws but still no effect on the motor. so i left it at 3/4.

from 700-800 rpm range it would cut out when i go to put it in gear. i'm thinking my controls need adjusting too. it also was a little more hesitate to start and idle properly

it seem to run better at 1k rpms then lower. i dunno.

i'll do somemore adjusting later.

when i did lower the idle rpm it did seem to have better wot but it was not consistent. it would go full then trottle down then full. it seemed more noticeable also when i hit bigger waves.