Yamaha 90hp No #2 Cylinder

Trying to figure out this 90hp 2 stroke #2 cylinder misfire (no fire).

[@degendyi]

I keep saying won't "fire" or "spark". I'm just saying it won't run. It has fuel, spark, air, weak compression.

[@WAH420]

It's in Limp Mode, it thinks it's overheating with the Hot Horn Buzzer going off the whole Time. Also unplug the Pink wire to the CDI and see if you get full spark. And Fix the Hot Horn Issue to ground...

[@motorob11]

CDI unit is likely what is causing that. I recently went through the same thing. Did all the testing I had the tools to do from the service manual. New CDI did the trick. That Potentiometer for the timing likely fails due to wear.

[@michaelcopete3466]

I’m currently going thru the same issue hopefully it is The CDI

[@motorob11]

It's definitely something electronic. No spark is certainly not to do with something mechanical like a cylinder. Do not tear your engine apart. There is some testing you can do to check the triggers off the flywheel. See that little POT with the lever on the CDI box. Carefully disconnect the linkage rod and move the lever around so it rotates the pointer on the box while you are idling. If nothing changes it's not working. That affects timing. The center cylinder on these will not fire until it's at a certain speed. If this POT is shot then that cylinder doesn't know that it should be firing. It runs terribly when you throttle up for the same reason. Timing.

[@JR03321]

Its probably your power pack.

[@dellanieparkes8360]

I had the same problem an i change the power pack an no more problem try it

[@THISOLDOUTBOARD1]

Hey. Good looking outboard! Got your message. I would think it should pop, 95 is not that low. Although you said the cylinder was glazed, where is all the unburned fuel going, is it coming out with the exhaust or dripping out later, the driveway looks pretty clean. Hopefully it's something simple. I'm thinking fuel. So it's got Spark, but is it strong? Will it jump a 1/2 inch on a tester? May just be weak and getting drowned out. Is the plug wet with fuel when you take it out or is it dry? If its soaking wet and it has a strong spark it may be getting too much fuel. If its dry its not getting enough fuel. Which could explain the lower compression. Pull the plug and shoot some fuel in the cylinder, hit the starter and blow out the excess, but not to much, then put the plug in and see if it fires, but you have to do it fast before the fuel runs out! I know you did the carbs but never assume anything with these things. What may seem like an ignition problem could be a fuel issue and vice versa. Check that cylinder with a timing light on the flywheel and see where its firing. Check the Powerpack leads, they may be crossed and going to wrong cylinders. That's about all I can think to check offhand. To Test the stator, trigger, rectifier You'll need a manual and a voltmeter and dva adapter. I know its a pain in the butt, trust me Hahaha! I had a hard time on the 60 Johnson but I got through it. But thats just me. Let me know what you find out.

[@georgemalek3398]

There is a coincidence. Service manual says there are 2 trigger coils, one fires cyls 1 and 3, the other fires cyl 2. Could be a shotted wire under flywheel that is

[@questsischiller4443]

I see sparks under flywheel, stator area . Not sure that is normal. Good Luck!

[@stevengilmore1509]

Watch the video at 4:50. Do I see arcing under the flywheel?

[@CrAcKhOrZ]

Did you check the electronic choke/ start assist actuator on the back of the middle carb. If it leaks it will flits no2 cylinder

[@edwincabrera5585]

CDI problems. for sure!

[@user-wy9et3ue6p]

Just check the sensor under tke flywheel I think they call it the striker.

[@sergiohernandez-uw7ch]

Hey bud. Check ohms on trigger wire and stator. If that’s all good along with coils. It’s your CDI box. I have the same engine and same problem. I just ordered a brand new CDI Box. Computer.

[@jeremyhoward8756]

Did you ever find out what was causing your motor to do this? I have an identical motor and it is doing the same thing. I have replaced so many parts on it I can’t even remember all of them. I did replace crank sensor and CDI unit with no change. Compression is good on all cylinders. I am about to be at the end of my rope with it.

[@degendyi]

Yeah I did. The middle carb was out of sync. I work in health care and been so busy the last couple years haven't had time to shoot a followup. Plus the Dams broke near me so a good test lake is at least 2 hours away so it's tough to get there. Had it out a month or so ago and she rips now. Still needs some tweaks but it's good. The butterfly in the center carb was off like a 16th inch. Very very slight. You could see it but had to be at the right angle almost. I knew it was off but didn't think it would cause this problem. Stumbled on this video kzbin.info/www/bejne/o6SxiIhmm6aWm9U and synced the carbs and I could tell instantly that it was better. Let me know what you find.

[@guyanesegamer1693]

Cdi unit is bad if you don’t get spark 1 and u swap coils cdi units go for 600 usd

[@bashaz8559]

How did you know it was not firing did you feel the difference in performance,, did you hear it?

[@danstefan5582]

Hi there! What year is this engine? And what model? I SEE is not with autolube system!

[@curtisconnell2243]

Did you ever get it figured out?

[@tandyhuynh3883]

CDI output number 2 no signal . no volt . out from cdi . check it . if yes change a new cdi.

[@robertdonald4409]

No spark is electrical ...glazed cylinders has nothing to do with that ... check your stator

[@sergiohernandez-uw7ch]

Did you ever get the problem Figured it out ? I have the same problem with my engine. But I did figure the issue. But I can’t find the part !!!

[@justinwright3250]

Try unplugging temp sensor or crankshaft position sensor

[@Watermen]

It's the CDI

[@StevenWilson-nq6cz]

Id say the carburetors are not in correct alignment or sync. Check those

[@michaelcopete3466]

Did you ever figure out what it was? I’m currently having this problem

[@degendyi]

Yes I did. It was a carb issue. I'm going to make a video on it as soon as the weather breaks. Check your carbs, make sure they are all set the same.

[@alanmerrill1626]

I see a spark jumping under fly wheel

[@proforugames1071]

Yea that's not ideal

[@texas357]

What year model is this motor?

[@sudilcyrus9590]

This motor still available

[@alanmerrill1626]

Did you ever get the motor fixed? And did the spark under flywheel have something to do with it?

[@Thunderbirds404]

If that no.2 cylinder ain't firing then it needs a rebuild, or... a replacement powerhead.

[@Mad.Man.Marine]

We’ll that’s a strong assumption not knowing. Most likely it’s in the cdi unit. The 90’s from the era have a kinda weird ignition system where 1-3 are on the same circuit and 2 is on its own.

[@sudilcyrus9590]

Selling?

[@brendastafford5114]

what did you find

[@StevenVincentSings]

So ?

[@brendastafford5114]

what did you find