85 hp Force can?t lower idle rpm

[mekkamaz]

Hi everybody, I have read a few post and find out some very good answers.

I have one that don?t let go....My '83 85hp force, got carbs rebuild (WE-4), good spark, new plugs, but I can?t lower idle rpm's , as at inital needle setting (about 1-1/4 turns), it starts at 1750, and linkage is loose, butterflys closed and choke wide open.

As I moved upper an middle carbs needles in-out, have no rpms movement, only better and worst idle (as lean-rich mixture moves), but at the bottom carb, then as I richen mix, it lowers at 1100..neutral.

Is this OKt?? double checked floats and no carb is flooding...

I thoght that carb does not control as much as rpm as linkage...only betters/worsen idle....

Thanks in advance for all the help

 

[Frank Acampora]

Re: 85 hp Force can?t lower idle rpm

You need to re-check synchronization AND TIMING at idle. Timing should be 0 degrees, plus or minus 2 degrees. Anything appreciably more than plus 2 degrees will increase the idle dramatically--even with the carbs fully closed.

Timing is the most important factor in acceleration. If you look closely, you will see that timing increases to maximum of 30 degrees BTDC while the carb butterflies are open only 1/4 of the way. This will usually give a speed only 3-5 MPH less than full throttle.

Get a Clymers Manual--They explain synchronizing quite well.

 

[Dave K.]

Re: 85 hp Force can?t lower idle rpm

hopefully one of the experts will chime in & tell you exactly what the problem is!

i have the same motor, '84..the factory set is 7/8ths turn out from litely seated..motor runs very good in nuetral & low rpm..

 

[Dave K.]

Re: 85 hp Force can?t lower idle rpm

there you go - frank knows...!

 

[Frank Acampora]

Re: 85 hp Force can?t lower idle rpm

For your info: Even though those square "tubes" along the outside of the triple manifold are balancing tubes to "balance" airflow between carbs, they don't do a good job and needle adjustments on individual carbs will typically have different results on the idle. Look closely and you will see that one goes from top to bottom carb, and the other goes from top to middle to bottom carb, usually has an oil recirculation hose between the top and middle carbs and an airbox drain below the bottom carb.

 

[mekkamaz]

Re: 85 hp Force can?t lower idle rpm

Thank you guys.

I thought that timing was ok since it shots ok, but will re-check timing.

Correct me please if I?m wrong, but the procedure will be to ground plug wires, open wot and then turn with starter, but the timing mark (little notch at flywheel will be 0, right?

And to adjust degrees, since has no more marks what should I do?

 

[mekkamaz]

Re: 85 hp Force can?t lower idle rpm

Now, I have 3 marks on the flywheel, as I remeber (since my manual got lost), the stand alone is TDC, and the other 2 should be 28-30 or 30-32?

And in which has tu be put at cranking timing?

 

[mekkamaz]

Re: 85 hp Force can?t lower idle rpm

Back again....I really need to find out what is it.....

Checked timing, Is 28 BTDC at WOT Cranking Rpms.

Still trying to locate the cause for the no low rpm control in this engine...look all over for cracks, holes, gaskets, trying to locate any air intrusion an none was found.

Set neddles at 7/8 (factory setting) and start over 1700 rpms...back again to 1 1/4...

Anyone????

 

[mekkamaz]

Re: 85 hp Force can?t lower idle rpm

Thank you Frank! Timing does the trick...and naow all is runnig smooth.

Good needle adjust, 1000 or less idling rpms....at last!!

Glad to have support like yours!!

Best regards.-