Running rough and popping.

[Scrid]

Trying to get my 84' Fj1100 back up to par. It's been neglected for some time while my parents were failing and eventually both passing.
I would put new fuel in this girl every year and start and run it around for a few miles.
This year it started fine but after a few days lost power and started running rough like a miss.
I pulled the bowls and washed them out. They weren't really that dirty, and then blew all the passages out with compressed air. I didn't like the carb slide diaphragms as they were still original from 84' so I ordered new ones that came with the slider too.
It runs better but the popping and chuffing is still there. Runs sorta better with the choke partly on.
Compression test last night revealed 150 across the board except #3 @ 148 lbs.
I feel like this is an ignition issue. The way it came on so fast. Today I ran straight power to the coils and it made no difference at all.
I just got done testing the coils and pick up coil.
According to my OEM service manual the pick up should be near 120 ohms.
Mine read 186 ohms on the orange to black / and 184 ohms on the grey to black.
Coil specs are 2.7 ohms Primary, and 12k ohms Secondary.
for coil 1 & 4 (left side) I got 3.6 ohms pri / 36.7 k ohms secondary
coil 2 & 3 (right side ) I got 3.5 ohms pri / 34.6k ohms secondary.
I tested the secondary right at the 45 degree plug boots where the threaded plug end goes in. Book didn't say I had to remove the elbows.
Kinda looks like I need new coils? Although the pick up coil resistance seems high too.
Something else I noticed was, that with a new spark plug as a "tester" on each coil wire,...the spark when running is a very thin almost purplish color. Didn't look real threatening like most ya see where you can actually hear it and its a bright yellow thicker flash.
Thoughts?
Thank you.
Chris

[T Legg]

Even though the manual says 120 ohms for tbe pick up coils both of my 1100's read 162 ohms and run fine .

[86FJNJ]

I just started using Yamaha ring free plus fuel stabilizer in my gas and I honestly feel like the bike ran a little smoother. It can't hurt to run that in your fuel as you're trying to get the bike in order. It's expensive but only 1 ounce per 10 gallons and should help clear out some passageways.

[FJmonkey]

Did you let any gas with ethanol sit in the tank? Might be plugged idle jets.

[86FJNJ]

This

[Scrid]

I won't put e10 in anything I own.
I will look into that Yamalube additive.
Thanks for that.

[Pat Conlon]

It runs better but the popping and chuffing is still there. Runs sorta better with the choke partly on.

Hey Chris....This ^^ is your clue.
Your choke / idle circuits and pilot circuits are still dirty. Disassembly and an Ultrasound bath is the sure way to clean those small internal passages. We have all tried carb soaking and compressed air only to have to repeat the process.
That ultrasound bath is the bomb for through carb cleaning.

I feel like this is an ignition issue. The way it came on so fast.

Get the carbs sorted out first. If the bike was running fine before it was parked and now it's not, 99% of the time it's carb related....(unless you have mice)

Congrats on those Great compression numbers....those '84 FJ's are special to me....

Cheers

Pat

[86FJNJ]

I won't put e10 in anything I own.
I will look into that Yamalube additive.
Thanks for that.

In NJ you can't get any fuel that doesn't have up to 10% ethanol so for me there is no choice. I was adding sabilizer to my fuel but at the suggestion of another member I tried the yamalube ring free with stabilizer and now I'll keep using that.

Pat is probably right a full carb cleaning is needed but I would be tempted to run the yamalube in the fuel for a few miles and see if it makes it just a little better just out of curiosity.

[Scrid]

Regarding the coil test results. I'm gonna re-run the tests with a Fluke meter later today.
I mean my secondary's are like 3 times the resistance they should be.
So the OEM service manual is wrong about the pick up coil resistance?
I think since 84' it's time to also replace the fuel lines. Is this thin walled hose still available?

[T Legg]

The pick up coils on both of my 84 FJ1100's read about the same. I was working on an electrical problem on one of them when I saw the resistance didnt match the value written in the manual. When I tested the one on my perfectly running bike I saw it was the same. I fixed the problem with the other 1100 and it then ran perfectly also. I dont know it the manual is wrong but the values of my coils are not 120 ohms.

[Pat Conlon]

Six years ago, I posted the same thing...

The ohm values for testing the pick up coils is INCORRECT in the Haynes and Clymer FJ manuals.
Throw those POS in the trash. They just cost you a set of coils you did not need to buy.

Use the ohm values in the Genuine Yamaha Factory Service Manual.
149-182 ohms when the coils are warmed to 68*f