Wandering Idle

[Trophy83]

Maiden voyage yesterday after 15 years of inactivity. 1984 Force 85.
Compression 125 each
Carbs rebuilt new needle and seat, gaskets, all idle circuit ports clear via spraying carb cleaner thru.
New fuel pump diaphragm and fuel lines
Drained and cleaned tank fresh fuel
Idle air screws 1 turn out
New BUHX plugs

Runs great at every level except idle, idle runs great but then it either wants to rev in neutral or slowly bogs down seems im chasing a consistent idle. If i lower its good in neutral but bogs in gear, drive the boat for a few mins (varying throttle positions) bring back down to idle in gear works fine sometimes, sometimes dies, adjust idle up and engine races in neutral and shifting gears is grinding. No matter which ay I adjust idle its either too slow or too fast

 

[nalegtx149]

i also would bang my head against the wall with stuff like this sometimes. My first thing to clear any issue would be to start from scratch. Sync and Link for your carburetors would be the easiest. Clymer's walk through for synchronizing your throttle linkage, dynamic/static timing, and carb tuning. YOU CAN'T carb tune or adjust idles until the recirc system is active (if so equipped). I'm sure others with better knowledge will chime in but this is where I've learned to always start. Make sure your basics are covered.

 

[Trophy83]

i also would bang my head against the wall with stuff like this sometimes. My first thing to clear any issue would be to start from scratch. Sync and Link for your carburetors would be the easiest. Clymer's walk through for synchronizing your throttle linkage, dynamic/static timing, and carb tuning. YOU CAN'T carb tune or adjust idles until the recirc system is active (if so equipped). I'm sure others with better knowledge will chime in but this is where I've learned to always start. Make sure your basics are covered.

Sorry forgot to say Ive done link and sync twice already. Actually runs great every where in the rpm band except for sketchy idle, sometimes good as in forward and low throttle and sometimes dies and or revs in neutral. uggh

 

[The Force power]

IF....I can throw in my 2 cents, I would check for intermittent spark

Check out these procedures;
http://www.cdielectronics.com/wp-content/uploads/2016/05/Tech-Guide-Digital.pdf

 

[Trophy83]

IF....I can throw in my 2 cents, I would check for intermittent spark

Check out these procedures;
http://www.cdielectronics.com/wp-content/uploads/2016/05/Tech-Guide-Digital.pdf

Wow Thank you for the manual!

 

[The Force power]

You're welcome,

look for your motor's procedure & follow to the T (don't skip things)
Also....try & see what happens with the air-fuel-mixture screw turned out an additional 1/4 turn (ON ALL CARBS)

 

[Trophy83]

So here is what i have found and done so far today.

Re did link and sync
re adjust cables and now have forward, neutral, reverse in the proper detents on shifter and completely engaging and disenging properly at the engine, readjusted throttle cable
The roller on the eccentric screw was very stiff (the nut was cranked on) the cam would come to rest in different positions due to cables and roller not adjusted properly
Someone installed a new stator, wires were interfering with the advance tower movement and being pinched behind

my local marina is only 3 miles down the road going down with cover off and adjusting air screws

may the force be with you, if i have to dig into the cdi boxes then there will be a lot of good parts on ebay lol. Thanks for the manual but after trying to read that Im not going there.

 

[Trophy83]

Ok results are as follows:

Removed cover launched boat adjusted air fuel screws, set idle sounded great! Reinstalled air box and cover and started doing the same thing stalling at idle in neutral and pain to put in gear. Seems like its starving for air when the cover is on. From my 2 stroke MX days also smells rich, not smokey but rich, plugs look great.

 

[The Force power]

Check for smoke coming from the rubber-tube going to the two holes in the back (on mid section) ALSO check for exhaust/smoke coming from cover on exhaust / Starter side AND check for smoke/ exhaust coming between power-head and adapter-plate. a good tool to use is a mirror!

Did you set the idle rpm while in gear? AND HOW do you adjust the RPMs

Run the crap out of it (in the lake) without the cover on to clear-up the system

 

[Trophy83]

Force, yes on smoke from both locations.

 

[Trophy83]

Check for smoke coming from the rubber-tube going to the two holes in the back (on mid section) ALSO check for exhaust/smoke coming from cover on exhaust / Starter side AND check for smoke/ exhaust coming between power-head and adapter-plate. a good tool to use is a mirror!

Did you set the idle rpm while in gear? AND HOW do you adjust the RPMs

Run the crap out of it (in the lake) without the cover on to clear-up the system

Seems there is smoke coming from under the starter. Setting RPM b ear, First in neutral warmed up then in gear tied to the dock.

 

[Trophy83]

Ok seems I have exhaust leak at adapter plate. I know one thing from living as long as I have. I’m not pulling the power head on this motor to replace a gasket. Since I only boat in extremely fair seas can I just drill a set of 4 1 inch holes in the cowling to vent the exhaust so I can get an idle?

 

[jerryjerry05]

If it runs better without the cover?? then there's an exhaust leak somewhere??

The air screws set at 1 turn out: the older motors they didn't respond to that setting, some did some didn't.
one customer needed to have his screws set at almost 3 turns out??

The final adjustment: in gear, in the water, not tied to the dock, rpm's set at 800

You said: "

Carbs rebuilt new needle and seat, gaskets, all idle circuit ports clear via spraying carb cleaner thru."
The spray cleaner might get some dirt but it won't get it all.
I use Chevron with Techron mix in 1/2 gal gas and proper amount of oil.
Run this through the system 20min. and then let it set for 24hr. Then run again 20min. and let set 24hr.
This should dissolve and deposits built up in the circuits.
The BEST way is get the kits for a rebuild and remove the welch plugs and see how much crud is in there??
Start with the bottom carb as the fuel mix settles to the bottom.
Also the fuel recirc system needs to have the screens replaced/removed.. ​

 

[The Force power]

Ok seems I have exhaust leak at adapter plate. I know one thing from living as long as I have. I’m not pulling the power head on this motor to replace a gasket. Since I only boat in extremely fair seas can I just drill a set of 4 1 inch holes in the cowling to vent the exhaust so I can get an idle?

By not fixing the problem correctly, the motor will carbon-up & die; drilling holes is not going to help!!
The exhaust fumes are Pos. pressure & your intake is Neg.pressure and will suck up all fumes first before the "fresh" air

You still did not tell me how you "adjust" your RPMs

 

[Trophy83]

I don’t have a tach. I can hear when a 2 stroke is at the right rpm and running cleanly ( I raced MX in the 70’s and 80’s). Everything works fine except at idle with the cover on. Again I’m not pulling the power pack regardless of what it does or doesn’t do, it’s a simple matter of expense and physical exursion. I’m going to connect a snorkel above the cowl like a ram air on old cars. It’s a 37 year old engine on $1000 boat/motor/trailer combo. It will work for what I want it to do. By pulling the power pack it will screw more things up than fix. I learned awhile ago not to fix things till I break them.

 

[The Force power]

You could clean the area & apply red engine silicone, that help sometimes

What I meant by how did you adjust;
Did you adjust the RPMs by advancing/retarding the timing? OR the shutters on the Carbs.?

 

[Trophy83]

You could clean the area & apply red engine silicone, that help sometimes

What I meant by how did you adjust;
Did you adjust the RPMs by advancing/retarding the timing? OR the shutters on the Carbs.?

Carb Shutters

 

[Trophy83]

You could clean the area & apply red engine silicone, that help sometimes

What I meant by how did you adjust;
Did you adjust the RPMs by advancing/retarding the timing? OR the shutters on the Carbs.?

Carb Shutters I dont have much choice as the previous owner had glued the timing block to the adjustment bar with epoxy. lol fortunately the timing is spot on.

 

[The Force power]

?? pictures please!

You have to set-up the carbs. per link & sync. procedure First.
Then when engine warmed up motor & in gear, you adjust the RPM's by the Tower-bar that moves the trigger-assembly. (and carb-shutters)

 

[Trophy83]

?? pictures please!

You have to set-up the carbs. per link & sync. procedure First.
Then when engine warmed up motor & in gear, you adjust the RPM's by the Tower-bar that moves the trigger-assembly. (and carb-shutters)

Ive done all that 3 times plus. When the covers go back on everything changes.