Merc 110 1972 refuse to start

[Sylva-Ranger]

Merc 9.8 hp 110 1972 Canadian Engine S/N 3269914

​Refuse to start, compression 115-110 very good and strong spark on both, new spark-plugs.ignition jump 1/4" easy.


​When put a little bit gaz on cylinder, if you crank fast sometimes made an exhaust, sometimes some kicks

​The fliwheel key is ok, the points cam key to.

TDC mark ok on flywheel.

​Phase marker points are adjusted at 0.020"

​Any ideas ?

​Thanks

 

[JDusza]

Fuel delivery is messed up.
Start at the beginning with a check of your fuel. Be sure it's clean and fresh and is premixed correctly (50:1).
Disconnect fuel line right after the fuel pump Put a rag around the exit of the fuel pump. When you pull the starter fuel should be pumped into the rag. If fuel is fresh and fuel pump is pumping then you're looking at carburetor cleaning / rebuild.
J

 

[racerone]

Checked crankcase compression ?-------Is choke going on fully and staying closed.

 

[Sylva-Ranger]

the fuel is new and the carb cleaned, the choke work properly........may be reed valves ?

​Crankcase compresssion ? do you mean check vaccum when cranking ? 2 strokes leak down test ??

 

[Sylva-Ranger]

Find a mag to coil wire whit the insulation broken at one place, and sometimes touching the block, change the wire the engine kick less but refuse to start again.

​I realy dont think is fuel related, because the engine refuse to start , even put fresh gaz directly on the cylinder and dont start more.

​Thinking may be a reed valve because when blowing by the plug hole find little bit air comming in the intake, reeds in old Merc are aroud the crankshaft and it's impossible to check all of them by the intake hole, so i removed the power-head and split the crankcase and everiting is ok, seems have no air leak and seals are like new.

​It's like the timing is out of adjustment, but the phase marker points are adjusted correctly , and blue strong spark jumping 3/8" on both, even turning the flyweel slow just at hand without using the rewind starter.......Try to index the 2 spark plug wires and refuse to start again.

​Do you think a defective module can make timing out of place ?

​Any other ideas ?

 

[60sboater]

There are resources here and CDI marine electronics in AL makes parts for many ignitions and has t-shooting information.

 

[Sylva-Ranger]

All ignitions parts seems good when testing whit my Ohmeter, but someting bizzarre...........When i check the ignition, can jump 1/4'' blue ignition on both cylinder, but when i put back the spark-plugs and trie to start, i saw whit the timing light that the number 1 cylinder begin to make erratic ignition............I tri an used ignition coil (green one) that i have on a old engine and it do same ting..........And whit my DVA there about 250 V on each coil........

I index the 2 coils and the problems move to no 2 cylinder for a wile but comeback to no 1

​Maybe not lucky and the 2 original coils and the one i put is bad to ? A new coil on Merc dealership is 158 $ CDN for each.

​Dont whant to put 316$ for to coil to finish whit a bad ignition module , and the module is NLA from Merc

 

[racerone]

May have some parts on hand for your motor.----Your location ?

 

[Sylva-Ranger]

May have some parts on hand for your motor.----Your location ?

​Duparquet, province of Qu?bec, Canada