1979 Evinrude 85HP v4 crossflow tune up "how"?

[flyingscott]

Where is the keeper for the throttle cam looks like it's trying to come off of the post . Should be clips and spring washers on it to hold it tight. Did you sync the carbs make sure both butterflies are closed. I would also suggest threading the plastic cam keeper about half way on to the so you have an even amount of threads out each side. I can see the clean threads where it used to be put it back there and start over again. That plastic roller has to be on there put small orings/washers on the shaft to keep it in place. That means you will have to re sync it and don't be afraid to move the carb arm to line it up again. It's a learning process don't get frustrated. When you do the low speed timing that is only where the carb roller and cam need to meet that is not where they will end up there is generally a gap between the two

 

[04xr6t]

No Title

Thanks flyingscott
Its hard when it doesnt operate the same as a car carby
I cant get my head around the motor running if the cam is not touching the carb ha ha
sorry to be a pest but can i walk you through what i have done, and see if i have misunderstood the manual in some way
I will attach pictures to show my steps

1/ put leg in a big water tub (make sure water does come out of tell tale pipe)

2/ hook up timing light to plug #`1
check timing at crank is at 4deg

3/ carry out j reeves WOT timing check
put powerhead lever to WOT
crank engine (timing at 24 deg) book calls for 28deg (minus 4deg as per j reeves)
"Engine Stalls" when started

4/ pull timing lever back on stop

(disregard missing splitpins and washers, as they have been left off for adjustments)

5/ adjust cam follower on carb (loosen flat bladed screw on carb linkage at set idle to 800 rpm)

6/ restart engine, idle goes up and down from 1000rpm to 2700rpm
then stalls out

Once again
If i do this on Muffs it runs perfect
put back in water (above symptons occur)

 

[racerone]

???-------The carburetor throttle plates must be CLOSED at idle.---------Idle speed is then controlled by retarding the timing.----And you will see a gap at the cam.--------It is supposed to be that way

 

[04xr6t]

ok now im completly lost
So what your saying is the thottle plate should not even be touching the cam on idle/stationary?

My link sync is 100% correct
4deg at idle and 24 deg at WOT

So what adjusts the idle up and down

 

[emdsapmgr]

There is a link arm that connects the two main carb butterflys together. p/n 316093. There is a screw clamp in the middle. If it's not adjusted correctly, at idle one carb main butterfly can be closed, the other can be slightly ajar. When you get one carb slightly ajar/open at idle, and the other closed,-you will get an up/down rpm variance. Pull the airbox cover off and check this. Don't get hung up about the idle timing. 4 degrees is a good place to start with idle timing. But you need to adjust the idle for rpm's and each boat/engine combination is different. You may or may not find 4 degrees is the magic timing. So, you must set it for the precise idle rpm, without worrying about getting it to exactly 4 degrees.

 

[04xr6t]

No Title

Ahhhhh making sense now
Now to through a spanner in the works
What if the timing screw is already wound all the way in (see pic)

I hope im not upsettin anyone, going round in circles :facepalm:

 

[racerone]

When the idle screw is turned all the way in it points to engine problems.--Answer this one.---Does spark jump a gap of 7/16" on all 4 leads , yes or no ?--Have you removed flywheel to inspect the key , yes or no ?---Have to do some trouble shooting and go one step at a time.

 

[oldboat1]

^^not much discussion of basics yet, and some may have been handled. But spark, compression, also temp. I get antsy when I hear about WOT operation in a barrel or on muffs, so hopefully not sustained h.s. running. May be preaching to the choir, but carbs should routinely be pulled off and disassembled for cleaning, if not done already.

 

[racerone]

Post #1 says that motor was " blown "---Now it is " running "----No mention of what was done and at what level of expertise either.----The idle stop screw all the way in points at problems !

 

[emdsapmgr]

Are you attempting to set the idle when the boat/engine are floating normally in the lake? That needs to happen. Once you submerge the lower unit/exhaust 20" under water there is a tremendous increase in exhaust backpressure. That increase will significantly lower the idle rpm's as a result. Each boat is different-each boat floats at a different level, based on the hull design and weight at the back end of the boat. Have you taken that into account?

 

[04xr6t]

Sorry guys, for the lack of basics
Below is what i have done (hope i dont bore anyone)
1/ bought boat with starboard head already pulled off (dont know why)
2/ carried out basic overhaul (maesuring up all items to within spec)
3/ replace power head gasket kit
4/ replaced all 4 sets of rings
5/ bores honed
6/ thermostate and water pump replaced
7/ fuel pump overhauled
8/ new fuel fines and connectors (inc clamps)
9/ Carbies cleaned with aerosol "carby clean" then blown out with compressed air (new gaskets and needle and seat)
10/ new spark plugs(B7HS Gapped to .35 thou .8mm)
11/ new fuel (45-1 mix)
12/ compression on all 4 cyl between 120-125psi
13/ base timing was already at 4deg
14/ WOT was already at 24deg
15/ testing all being done in a tank (not muffs)

 

[flyingscott]

One more question what did you seal the crankcase halves with.

 

[04xr6t]

Permatex ultra grey
http://www.permatex.com/products-2/...-high-torque-rtv-silicone-gasket-maker-detail

 

[racerone]

Sealing the crankcase is " critical work "-----I only use OMC gel seal or loctite 518.

 

[flyingscott]

Did you let the ultra gray set-up before you torqued everything

 

[04xr6t]

If you mean did i let the silicone dry first. No i torqued the crankcase while it was wet.

On the note of sealing crank case.
Is the timing arm meant to have a oring or something sealing the bolt to the block?

 

[racerone]

Silicone is not to be used on those surfaces.------Only a sealer with no " filler " material.------The 2 halves are a precision joint and MUST go metal to metal for proper bearing clamp-up.--------Just took a 3 cylinder 70 hp apart where the assembler had omitted the o-ring on the upper bearing.---Did not locate the upper bearing properly on the dowel pin.-----That means there was a leak.---Someone used a centre punch to try and stop the leak around the bearing.---This is precision stuff and requires carefull work.---No o-ring on that bolt.--a drop of gasket sealer works well.

 

[04xr6t]

Thanks raceone
might be time to strip and reinspect
The silicon i used (in the above link) would you say that is the incorrect gasket former?

 

[racerone]

Answer these questions--What is the piston to cylinder bore clearance ?----That is to be measured just above bottom of the skirt.---Did you measure cylinder bores ?---Did you install new rings in possibly worn out piston grooves?---Does spark jump a gap of 7/16" , yes or no ?

 

[04xr6t]

1/ piston to bore clearence was large (cant remember) but i know it was excessive
2/ Ring gap (perfect) within spec(brand new 30thou over sized rings, to match piston oversize)
3/ spark easly jumps 11mm (aka 7/16)