ignition help ! 30 hp

[lasse]

Hello 1

My -89 30 hp (3-cyl) is not running on the upper cylinder.
I've swapped coils, and cleaned the carb- no change.
when I pull the plug on the upper cylinder nothing happens. On the other two the engine dies.
Question- Where do I go from here ?
How do I test the CDI unit ???
As it is a 30 DE (european) speck, I'm not sure what manual will fit...
Do they all have the sdame ignition ??
Help ;^)

Lasse

[tripleb]

Hey lasse,

Have you tested compression on all 3 cylinders? There should be no more than 10% difference.

[nzap]

I am having the same problem with an 89 40hp it runs rough and misses but does not change when the plug boot is removed from the one cyl. and it is getting plenty of spark, but does change when other plug boots are removed.....please help its driving me crazy

[lasse]

I'm pretty sure the compression is OK.
The last owner repaced the thermo-swich,
so I don't think this is causing the problem.
Any tips on how to proceed?
(BTW: the price of a new rotor assy unit in Norway is $1200, the repair guy demands $70/hour).
Was hoping to fix this with help from the forum, and parts from here!

Lasse

[tripleb]

Hello lasse and nzap,

Ok, you still have too many variables here. You cannot assume that the compression is good. You gotta test it. Also, you should take the carb(s) off the motor and clean completely (break down) and are you sure the cylinder that is not "running" is getting fuel?

[nzap]

tripleb,

the compression is good the carbs have been cleaned and rebuilt and it is getting fuel you can see fuel going in while its running in all three carbs... still lost help

[tripleb]

Hey nzap,

Well if you are certain that compression is good, carbs are clean, fuel is getting into carb(s), and you have "good spark" then I am uncertain what may be wrong ..... bad spark plug????

[Island Guy]

Try sinc and linking your carbs. I've had problems in the past with both the 30s 40s and even some 50 triples. The top linkage could be worn and the throttle plate just not opening at idle. Remember it is an 89. Probably a lot of hours on it?

[nzap]

the plugs are new and i did change them again to make sure thats why it is blowing my mind i am going to look at the linkage tommmrow to see if there is a issue there bu it looks fine and overall it is a low hours motor for being an 89.
also i am going to try swapping one of the carbs from another cyl to the bottom one to see if just maybe it is the carb

[lasse]

I was thinking of swiching carbs aswell, but I'll try one thing first, checking the pulsator coils.
Just pull the black plug, then read the Ohms between the black and the 3 white/colored wires.
should all read around 3-400. If this is OK I'll give the carbs another go..

Lasse

[nzap]

well figured out tonight that it was in fact the carbs, i found this out by switching the carbs and it running find on the cyl. and not on the other that i put the bad carb on....thanks for your help

nick

[jb123]

soooo many want to blame electronics when carbs are dirty, and dont cheat your motor of fuel by doing a seafoam treat...take an hour or 2 of your time and CLEAN CARBS !! glad to hear you fixed your issue.

[lasse]

me not so lucky- Swiched carbs- same problem.
measured compression all same, 9 bar.
Measured pulsator coils 375 ohm on all...
Motor close to junkyard...

Lasse

[tripleb]

Hey lasse,

Are you getting spark on the cylinder that is not running?

Can you spray some gas into the associated carb to see if the cylinder will "fire"?

[lasse]

Turns out it was no easy task for the workshop either-
Their present theory is leaking head gasket or cracked cylinder wall or a piece broken off the piston skirt. All extremely rare, and not DIY.

Thanks for all help !

Lasse