Idle/RPMs too low - boat won't idle

[nateo]

Starts up fine in wot. Got her warmed uo but engine dies when i back throttle down to idle. Havent even tried shifting yet. Starts right back up. Doesnt seem to be a kill switch issue. This came up after i replaced shift cable. What am i misiing? Seems like a adjustment of some sort. Tried adjusting idle screw, didnt help though.

 

[nateo]

I realize theres probably more varibkes at play here then just shift cable. Dont remember if i put fuel stabilize r in this winter. Adjustment or gas problem?

 

[HT32BSX115]

Howdy,

Fuel stabilizer is not really much of a factor in less than 1 year old fuel. [BUT, having said that, drain the tank and put some fresh fuel in it to eliminate the fuel being a problem. You can always use it (diluted with fresh fuel) later]


Your problem is more likely an adjustment problem. When you pull the throttle back to the idle detent, it should NOT be placing excessive "CLOSE" {vs open] 'pressure' on the throttle butterfly control.

You determine this by removing the cable connection AT the carburetor ...........and doing the idle adjustment [in NEUTRAL] prior to re-installing the throttle cable (this allows ONLY the carburetor return spring to close the throttle butterfly)

THEN, you adjust the throttle cable at the carburetor so that it can be reconnected without placing any additional "close" pressure on the carb butterfly linkage............


Regards,


Rick

 

[NHGuy]

So you are saying after replacing shift cable. Check that the cable is properly adjusted before you make changes to the carb etc.
If the cable isn't adjusted right it can cause the shift cutout to actuate. The cutout is there to momentarily kill the spark just long enough to allow the gears to disengage when taking the shift to neutral. It only works in the water.
If you would like a video on how it's adjusted go here https://www.youtube.com/watch?v=-s_t...ature=youtu.be

 

[nateo]

So you are saying after replacing shift cable. Check that the cable is properly adjusted before you make changes to the carb etc.
If the cable isn't adjusted right it can cause the shift cutout to actuate. The cutout is there to momentarily kill the spark just long enough to allow the gears to disengage when taking the shift to neutral. It only works in the water.
If you would like a video on how it's adjusted go here https://www.youtube.com/watch?v=-s_t...ature=youtu.be

Haven't even tried putting it in gear yet. Cant get it to idle in water. Rpms drop too low. Will idle on muffs with idle screw turned all the way up

 

[nateo]

Ok, so basically I've come to conclusion that my problem is that I'm not getting enough rpm's at what is should be idle. I adjusted both idle fuel/air mixture screws to the 2.5 turns from bottom (default setting). I then tightened idle screw all the way so that I'm getting the highest idle possible. However my rpm's will be around 4-500 and engine will die. (this is when boat is in water) If I throttle up a we bit to 650-700 rpm's everything is fine. However throttle lever is about a quarter of a inch from idle screw. Checked fuel filter, not clogged. When at home on muffs with same setting for the idle set screw, my rpms are about 650 and everything fine. No back pressure I can see that. Just not sure why my rpms are couple hundred lower then what they should be.

 

[NHGuy]

Is it timed to 8 degrees btdc? If the timing is too far back it will take more throttle to get engine speed.

 

[achris]

Check you didn't know a spark plug lead off during the shift cable replacement. Also make sure your distributor isn't loose, and got moved...

 

[nateo]

Checked all plug wires, all secure. Hooked up timing light and appears to be dead on (on muffs). Distributor not loose. I fixed the timing last year and tightened that sucker down good. I just got done putting about 80 hours in this sucker rebuilding motor mount, replacing impeller, engine coupler, and shift cable. I'm down to the end of my rope on this dang boat. I'm hanging on to the swim platform and it's dragging me around. The propeller is chewing me up right now. I've clicked my heals three times and I'm still not on the water...heelp..

 

[nateo]

Is it timed to 8 degrees btdc? If the timing is too far back it will take more throttle to get engine speed.

Is it critical to have boat in water and in forward gear to check timing or can jt be done on mufs as long as rpm js between 650-700?

 

[Bondo]

Ayuh,..... Idle on the muffs is fine,....

 

[nateo]

I just thought of something that is making me sick. When i spun coupler i was wot. Could this be a damaged engine such as no compression in one of the cylinders or something along those lines?

 

[nateo]

I started looking at all my wires this morning and I found the positive battery terminal was loose. There are two red wires. Still in storage can't test until tonight but this might be smoking gun here.

 

[H20Rat]

Although not impossible, a bad terminal connection probably isn't going to cause the idle. (again, not impossible, but...) I'd maybe research the compression a little more! How does the engine start? Same as last year?

 

[nateo]

well tightened down both battery connections, same results. Seems to take a little longer to start then last year.

 

[nateo]

I'm close to surrendering my propeller.

 

[nateo]

What rpm should idle be at on muffs? After cleaning carb and tightening battery connection it appears to stay running now on muffs at idle but rpm is only about 490-500

 

[Bondo]

Ayuh,.... I usually set it at 650/ 700 where it supposed to be, 'n adjust in the water in gear, if necessary,....

 

[flipbro]

Have you done a compression test since problem?

 

[nateo]

plan on checking compression tomorrow after work. One other question until then. Could a we bit of bad engine alignment cause this issue? I had spline marks all around on alignment bar but wasn't absolutely sure as it didn't slide back out effortlessly.