Force 85 set-up

[Craig cK]

Hey guys!<br /><br />Wonder if you can help me at all? I've spent about 2 hours on it now and me back is killing me!<br /><br />I have a small RIB with a Force 85hp which was only developing 27 knots so figured something was up. I removed the carb covers and found the throttle butterflies were hardly opening. <br />I have since fiddled with all the settings and buggered the whole lot up trying to fix it!<br />Could anyone point me in what direction to go to set up the timing etc etc. I presume there is an order to set these things up? I don't really want to invest in the workshop manual as I suspect it will never be used again and am normally pretty good with all things mechanical.<br /><br />Your help is greatly appreciated!

 

[roscoe]

Re: Force 85 set-up

Lync and sync on a multi carb 2 stroke requires a manual, preferably an oem factory manual. Clymer repair manual may get you thru it. Don't want to buy one?, try the local library technical publications department.<br /><br />If you don't get it right, she'll blow up, literally.

 

[Craig cK]

Re: Force 85 set-up

<br /><br />Owwwwwwww :'( :'( :'(

 

[Craig cK]

Re: Force 85 set-up

Ok....well I see the timing marks etc so presumably I use a timing light powered off no. 1 cylinder. Is it not just as simple as that?<br /><br />Set up the initial timing under cranking and then confirm when running?<br /><br />The thing that scares me is how the timing advances when the throttle is opened. Will this just sort itself out?<br /><br />or is it a case of cranking the engine and setting up the timing with WOT?<br /><br />Thanks guys! Really don't want to get the manual if I can possibly help it! For a start it would take ages to get shipped! I think you guys can help more quickly!

 

[roscoe]

Re: Force 85 set-up

Initial setting of timing is easy.<br />Setting the timing advance with the linkage and cam can be touchy.<br /><br />""I have since fiddled with all the settings and buggered the whole lot up trying to fix it!""<br /><br />Not knowing what settings you fiddled with, it is hard to say how to fix it.<br />Would hate to give you bad advice and cause more trouble.<br />I have oem factory manuals, but none that cover your motor, so couldn't advise anyway.

 

[t.martin]

Re: Force 85 set-up

First of all if your butterflies weren't opening all the way why did you mess with the timing linkage? I don't know what year your motor is but I can tell you on my motor (1986 85hp prestolite ignition) WOT #1 cylinder 28 degrees BTDC. If it is not a prestolite it should be 30 degrees. Your flywheel should have marks for this. Check timing by cranking not starting.

 

[Craig cK]

Re: Force 85 set-up

Thanks guys! I played with the timing as I couldn't seam to manage to get the engine to tick over while at the same time be able to obtain full throttle. It seams to be a bit of a balancing act! <br /><br />Fingers crossed!<br /><br />I'll have a go and keep you all posted.

 

[t.martin]

Re: Force 85 set-up

If you get the timing set I would rebuild the carbs. I think that is where your problem lies.

 

[Craig cK]

Re: Force 85 set-up

I've re-built the carbs they are fine, yu can physically see the butterflies were only opening say a 1/4 of the amount they should.<br /><br />Just invested in a timing light...so off to play!

 

[Craig cK]

Re: Force 85 set-up

All good! Been out for some sea trials and she's back up there at 35 knots or so. Wahoo!<br /><br />However, she's now not ticking over, but I hope I can sort that tomorrow!<br /><br />Also want to set the timing to 28 or so...but that's not a priority at the mo!<br /><br />Thanks for all your help!