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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: iridewheelies on July 20, 2019, 09:26:11 PM



Title: Tune up - read the plugs
Post by: iridewheelies on July 20, 2019, 09:26:11 PM
Here's a pic of my plugs. 1-2 are white and 3 is dark and tan, 4 is darker too. Why arent my plugs even? 115 mains 40 pilots, stock bleeds around 3 and a quarter out on the screws, 4-1 Vance Hines uni pods needles shimmed with rpm parts. Carbs been gone thru, wanna clean them again. Wanna check the valves, valve cover seeping a bit, but the bolts weren't that tight where it was leaking so I snugged up. I dont have a tool to get the shims out, so will hold on the valves the bike starts first click when cold, will crank for a bit and need some throttle when hot. Idle good, just slow on the blip test and back to idle when clutch pulled. I have a set of gauges.


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 20, 2019, 09:26:57 PM
Idk why its upside down.


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 20, 2019, 09:28:46 PM
Also will be checking float levels, I did them once but wasnt sure how to measure so i didnt really make any adjustments. Bike will run out of gas when going interstate speeds for long times


Title: Re: Tune up - read the plugs
Post by: krusty on July 21, 2019, 12:53:31 AM
It may help to know over what time period they became the way they and under what driving conditions. Commuting, touring, boy racing, solo or two up, rev range etc.


Title: Re: Tune up - read the plugs
Post by: Pat Conlon on July 21, 2019, 12:57:13 AM
Bike will run out of gas when going interstate speeds for long times


Funny how that happens....

Seriously, you have a ‘85 with a gravity flow fuel system, do you have your fuel line routed correctly?
Read this: http://www.fjowners.com/index.php?topic=18286.0 (http://www.fjowners.com/index.php?topic=18286.0)
Your fuel line should look *exactly* like this picture....not close, but *exactly*


Title: Re: Tune up - read the plugs
Post by: Sparky84 on July 21, 2019, 02:29:59 AM
Bike will run out of gas when going interstate speeds for long times
Same problem here after about 390k’s and it’ll do that at least twice before I make a state border..


Title: Re: Tune up - read the plugs
Post by: ribbert on July 21, 2019, 05:43:15 AM
Bike will run out of gas when going interstate speeds for long times


Funny how that happens....

Seriously, you have a ‘85 with a gravity flow fuel system, do you have your fuel line routed correctly?
Read this: [url]http://www.fjowners.com/index.php?topic=18286.0[/url] ([url]http://www.fjowners.com/index.php?topic=18286.0[/url])
 :Facepalm:


Pat, I've owned dozens of gravity fed bikes but never an FJ
 FJ, I'm curious every time someoone posts this. Can you explain why, if all the lines are below the tank, the exact configuration matters?


Title: Re: Tune up - read the plugs
Post by: Pat Conlon on July 21, 2019, 10:39:00 AM
....Can you explain why, if all the lines are below the tank, the exact configuration matters?

Hi Noel, sure....the oem Yamaha fuel lines are relatively thin walled (compared to today’s high pressure fuel line)
What happens is when the under tank environment heats up the fuel line gets softer and within some time if the hose is at a wrong angle it will pinch off fuel flow.... if this *exact* routing is not followed.
Yes, This routing is counter intuitive. Looking at it you would think: “This can not be correct”, but it is.

*What you don’t realize is the 1) downward angle of the petcock outlet and 2) how low the fuel outlet on the petcock sits, once the fuel tank is lowered into position*
If you run the single fuel line over the 2 branch lines, because of the outlet level and angle, you will get a pinch on the single line.

Here are the symptoms of a pinched line:
1) Bike cold starts fine, runs fine until getting warm or hot...then the bike starts stumbling like it’s running out of fuel (which it is)
2) Bike cools off, starts fine, runs fine until it gets warm, then symptoms reappear.


Title: Re: Tune up - read the plugs
Post by: FJmonkey on July 21, 2019, 10:48:35 AM
Pat posted before I could.

Pat, I've owned dozens of gravity fed bikes but never an FJ
 FJ, I'm curious every time some one posts this. Can you explain why, if all the lines are below the tank, the exact configuration matters?
On my 86' the fuel line has little room under the tank once the tank is seated. If the line is not OEM routed, or altered as some have successfully posted; the line can get pinched from the tank pressing down on it, or kinked. Either way the 10mm line is restricted. The amount of restriction, the amount of fuel in the tank, and throttle position  determine when starvation occurs.

To be more specific to answering your question, the part of the line from the petcock to the loop around carb 3 tends to get routed over the split line dropping between carbs 2 and 3. This is not intuitive when you have to lift the tank to make the connection to the petcock. Routing it under is OEM. Routing over can cause the pinch. 


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 21, 2019, 02:32:13 PM
It may help to know over what time period they became the way they and under what driving conditions. Commuting, touring, boy racing, solo or two up, rev range etc.
[/quote

I mainly use the bike to commute and cruise around, I dont put it under high load very often, and when i do, the bike flies. I have upgraded my line to 5/16 I think? Ik its larger inside, high pressure fuel line. Routed correctly under the t, but I have the twist fully around the top of the carb, theres a little bracket to hold the hose there. The bike runs great at any rpm. I wanna get the plugs tan, And I want my rpm to go down to idle faster. Blip test shows very slow on back down to idle. Carbs out of sync? I replaced manifold o rings, sprayed carb cleaner everywhere while bike running, no idle change. Bike idles real low when hot, will start there


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 21, 2019, 04:52:43 PM
The bike has always ran like this. Bought it at auction and got her going myself


Title: Re: Tune up - read the plugs
Post by: racerrad8 on July 21, 2019, 05:21:50 PM
A couple of things...

1) You cannot really diagnose the carb jetting by the photos. The lighting is not enough and you can't really see the spark plug that needs to be examined.
2) Those spark plugs have never been properly torqued when installed. The "crush" washer to ensure sealing of the combustion pressures and making sure there is a proper ground path has never been crushed.
3) Fuel line routing is important as already mentioned.
4) The petcock diaphragm could have a hole in it and not able to keep the proper fuel flow.
5) The fuel cap vent could be causing a vacuum in the tank and should be checked.
6) You need to ensure the valve are adjust to specifications before tuning on the carbs.
7) Once the valves are properly adjusted the carb sync is the next step.
8 ) What is a stock bleed? There were several different sizes of "stock"
9) What bike are you working with, 1100/1200?
10) If 1100, flat or curved slides?
11) Stock or aftermarket ignition system and coils?
12) Has the ignition timing been altered?

And finally, you mention you want to clean the carbs again. You cannot tune a set of carbs that are dirty and have altered fuel passages. The base of the carburetion needs to be solid before any tuning can occur.

Randy - RPM


Title: Re: Tune up - read the plugs
Post by: ribbert on July 22, 2019, 08:11:43 AM
....Can you explain why, if all the lines are below the tank, the exact configuration matters?



Thanks Pat and Mark, if it's a pinching issue, that makes sense.

Noel


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 23, 2019, 05:56:37 PM
A couple of things...

1) You cannot really diagnose the carb jetting by the photos. The lighting is not enough and you can't really see the spark plug that needs to be examined.
2) Those spark plugs have never been properly torqued when installed. The "crush" washer to ensure sealing of the combustion pressures and making sure there is a proper ground path has never been crushed.
3) Fuel line routing is important as already mentioned.
4) The petcock diaphragm could have a hole in it and not able to keep the proper fuel flow.
5) The fuel cap vent could be causing a vacuum in the tank and should be checked.
6) You need to ensure the valve are adjust to specifications before tuning on the carbs.
7) Once the valves are properly adjusted the carb sync is the next step.
8 ) What is a stock bleed? There were several different sizes of "stock"
9) What bike are you working with, 1100/1200?
10) If 1100, flat or curved slides?
11) Stock or aftermarket ignition system and coils?
12) Has the ignition timing been altered?

And finally, you mention you want to clean the carbs again. You cannot tune a set of carbs that are dirty and have altered fuel passages. The base of the carburetion needs to be solid before any tuning can occur.

Randy - RPM

Thank you Randy with the great advice. I thought the plugs seemed loose...I haven't been under the tank since the bike sat all winter, so I must have been running it like that for a few thousand miles. Wow.
Valves are coming soon waiting for the tool to come in. (Even though I dont need the tool to check clearances)
The bike is an 1100. Stock ignition and coils. No advance that I know of.
Pretty sure they're curved slides. 155 air bleed. I have an aftermarket gravity petcock with a fuel bowl, so flow age is not a problem I should get plenty of fuel.


Title: Re: Tune up - read the plugs
Post by: racerrad8 on July 23, 2019, 06:15:04 PM
I have an aftermarket gravity petcock with a fuel bowl, so flow age is not a problem I should get plenty of fuel.

Are you sure about the petcock?

I see the fuel line diameter is reduced from 3/8 to 5/16 at the tee. The stock line is 10mm and larger in diameter than the 3/8 that is installed.

Secondly,  are the orifices in the petcock big enough to flow enough fuel.  If they are not at least .375", then I'm not sure if it does flow enough.  

I'm also wondering about restrictions of the gravity feed system by having to fill the bowl and then flow to the carbies.

Do you have some photos of it?

Randy - RPM


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 23, 2019, 10:07:32 PM
 :Facepalm: I replaced the fuel line when I bought the bike and A. Never really thought of getting the correct metric fuel line, just went with what I had lying around the shop. B. With the tank back off I am seeing some weeping around my aftermarket POS petcock. The seller stated that it flows more blah blah but I should have known just by looking at it. Pulled out my box of old parts, and the vacuum petcock is definitely a lot larger. I think I'm going to put it back to how it was. Along with correct fuel line, and maybe even fix my fuel gauge. Lol. Also, isnt there suppose to be o rings here??? Where the cerrrbs go into the manifolds. Lmfaoo


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 23, 2019, 11:01:26 PM
She has seen her share of abuse, and I have some dirty ways


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 23, 2019, 11:06:24 PM
I wonder if the odometer rolled over... it reads 12k lol on the bright side I pulled the carbs apart I hope the bowl gaskets are reusable they are in decent shape not very old. Glad I cleaned them though, I actually put some bad gas through it (87) no ethanol though, I was in a pinch. The jets were definitely pretty dirty, all the pilots showed noticable change of light thru them just by blowing (oh yah) them. Emulsion tubes (or whatever) dont look to be worn out. Looks to be a few simple nick nack fixes and a can of cerb clean. Ps. Look at the abuse....


Title: Re: Tune up - read the plugs
Post by: RPM - Robert on July 24, 2019, 08:20:45 AM
No there are no o-rings there. The o-rings on the intake manifolds are on the back side and seal against the head. The groove on the carb body mates with the intake manifold. Stick your finger in there and feel the ridge.


Title: Re: Tune up - read the plugs
Post by: ZOA NOM on July 24, 2019, 10:15:26 AM
Please address all of the fuel lines with the proper Yamaha parts...

http://www.fjowners.com/index.php?topic=17320.0 (http://www.fjowners.com/index.php?topic=17320.0)


Title: Re: Tune up - read the plugs
Post by: ribbert on July 25, 2019, 08:48:22 AM
Rick, I understand the sentiment here but "OEM Spares' is not where you get fuel line from.

It needs to be fresh, buy it from a store with turnover, not something that could have been sitting in a bag for 20 years and pay 4 times the price for it as well. There's also a chance the new hose may be better. I buy fuel line 10m at a time, it lasts me a couple of years these days and I reckon that's long enough.
I've had "new/stale" fuel line split as I've pushed it on, cut a new end, split again and so on. It is why I don't like having too much hanging around.

Use proper fuel hose clamps, not worm drives.


Fuel line, like most other peripheral components, is not made by Yamaha anyway.

Noel


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 25, 2019, 11:22:40 PM
Update. Carbs still apart. Emulsion tubes dirty. Cleaning up. Here's a pic, tubes on carbs 1, 2 look newer than 3,4! Odd! They dont look ovaled out... everyone learns someday! Lol


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 25, 2019, 11:23:35 PM
Gonna clean them with some thin wire


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 26, 2019, 03:11:05 AM
Can I measure float levels like this? I am measuring to the tallest curved part of float, with no gasket. The needles are shut, with the needles just barley resting on the float. There was around 2mm between them beforehand, roughly measured 25.6mm on each level give or take. Reset to 21.78 +- .3


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 26, 2019, 04:04:31 AM
Think i got it.


Title: Re: Tune up - read the plugs
Post by: FJ_Hooligan on July 26, 2019, 08:01:48 AM
Update. Carbs still apart. Emulsion tubes dirty. Cleaning up. Here's a pic, tubes on carbs 1, 2 look newer than 3,4! Odd! They dont look ovaled out... everyone learns someday! Lol

If the emulsion tubes are oval shaped then they are worn out and need to be replaced.  

When they get oval, the needle is not as effective at controlling fuel flow and the mixture will tend to get richer.  That's why plugs 3 and 4 look richer.  You could try dropping the needle slightly to compensate but it would just be a guess.  

New tubes is the correct answer.

Also, on the float level I'd shoot more for 23 to 24mm.


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 26, 2019, 08:24:21 AM
If the emulsion tubes are oval shaped then they are worn out and need to be replaced.  

When they get oval, the needle is not as effective at controlling fuel flow and the mixture will tend to get richer.  That's why plugs 3 and 4 look richer.  You could try dropping the needle slightly to compensate but it would just be a guess.  

New tubes is the correct answer.

Also, on the float level I'd shoot more for 23 to 24mm.
[/quote]

They did clean up well. I don't believe that they are worn out quite yet. Will pull them back out today and get a good inspection in the sunlight. It maybe a little difficult to spot the ovaling at first, but I spent around 10 minutes with a high powered light, shining through different angles to be sure they arent worn. Will set them to 23mm as well


Title: Re: Tune up - read the plugs
Post by: FJ_Hooligan on July 26, 2019, 10:42:27 AM
They did clean up well. I don't believe that they are worn out quite yet. Will pull them back out today and get a good inspection in the sunlight. It maybe a little difficult to spot the ovaling at first, but I spent around 10 minutes with a high powered light, shining through different angles to be sure they arent worn. Will set them to 23mm as well

Better yet, swap the 3 and 4 tubes into the 1 and 2 carbs and see of the dark plugs follow them.


Title: Re: Tune up - read the plugs
Post by: ZOA NOM on July 26, 2019, 12:09:11 PM
Rick, I understand the sentiment here but "OEM Spares' is not where you get fuel line from.

It needs to be fresh, buy it from a store with turnover, not something that could have been sitting in a bag for 20 years and pay 4 times the price for it as well. There's also a chance the new hose may be better. I buy fuel line 10m at a time, it lasts me a couple of years these days and I reckon that's long enough.
I've had "new/stale" fuel line split as I've pushed it on, cut a new end, split again and so on. It is why I don't like having too much hanging around.

Use proper fuel hose clamps, not worm drives.


Fuel line, like most other peripheral components, is not made by Yamaha anyway.

Noel


Very good advice, Noel. My issue was not the fuel line, I used the term generically. It was a non-Yamaha fuel filter. The nipple was a little too large for the hose, and a split was the result.


Title: Re: Tune up - read the plugs
Post by: iridewheelies on July 26, 2019, 12:51:34 PM
No fuel filter on my bike. I very thoroughly cleaned the tank, I filled it with nuts bolts chain saw blade pieces. Got more 3/8 hose from my shop and some safety wire, I replaced the o ring cuz mine popped out without much resistance