What's going on here? This doesn't look right.http://www.flickr.com/photos/95019607@N00/7860607972/#in/photostream/ (http://www.flickr.com/photos/95019607@N00/7860607972/#in/photostream/)
Your Goth nail polish needs touch up. Plug looks rich. Just one cylinder or all of them?
Comedy! my kids got a hold of me! FJMonkey all 4 plugs look like this
I am not a carb guy so you will need their help. But they will need more information about your current bike set up. For example, what were the riding conditions just before you pulled the plugs? Stock carbs? Jet kit? Stock seat or Corbin? Lefty or Righty? Toilet paper over or under? the entire works.... Spill it...
All stock set up. Carb kit from Randy. Regular riding. Don't really know what else there is to say. After blipping the throttle idle hang just for a second or two then settles into normal idle at about 1000 rpm
Quote from: Tapartacus on August 25, 2012, 08:28:02 PM
All stock set up. Carb kit from Randy. Regular riding. Don't really know what else there is to say. After blipping the throttle idle hang just for a second or two then settles into normal idle at about 1000 rpm
Not really knowing the carb stuff I am gonna guess the needles are a touch to high letting too much fuel in.
Come on carb guys help out!!!
(http://farm9.staticflickr.com/8289/7860607972_af03ac1bb1_b.jpg)
Is this after a good run, or just idling in the garage? Choke moving freely and turning all the way off?
Please, details about the Randy carb kit
By a general rule, you must set first the main jet before touching anything more
Probably sort the idle out, by turning the " mixture " screws in on top of the carbs, all the way in till they just seat, the wind them out 2.5 turns each,
So I turned the mixture screw IN a half turn. Blip test is solid, as idle returns normally with no hang or drop. Stock kit for 92 -
#110 Main Jet
#155 Air Pilot Jet
#42.5 Fuel Pilot Jet
from RPM. Left stock needle in, not adjustable.
Still rumbles on the deceleration at 1500 rpm,(and by stumble I mean I can feel a distinct vibration on deceleration under my ass while coming to a stop, my 89 does not do this) maybe I need to lube engine mounts, a little leery to do that though not too sure of my skill set. Anyway thats all I have. Thanks for the replies.
It is rich as noted by the sooty black plug.
It could be:
Idle mixture adjustment
Too large pilot jets
Float level too high
Fuel leaking into float bowl bypassing N&S (float level)
Choke circuit not closing fully
Dirty air filter
Carb Sync
Randy - RPM
When I noticed roughness during decelleration on my '93, it was frozen motor mounts.
That 42.5 idle jet is not helping the plugs.
DavidR.
Hi David, did you fix the mounts? Did it help?
Andrew
Quote from: Alf on August 26, 2012, 03:59:29 AM
Please, details about the Randy carb kit
By a general rule, you must set first the main jet before touching anything more
Please help my understanding. When working on jetting in the past (mostly dirt bikes) we started with pilot jets and worked up from there? Because of the overlap. Is this different on four cylinder street bikes? Thank's for your input.
Kurt
Quote from: yamaha fj rider on August 26, 2012, 11:29:28 PM
Quote from: Alf on August 26, 2012, 03:59:29 AM
Please, details about the Randy carb kit
By a general rule, you must set first the main jet before touching anything more
Please help my understanding. When working on jetting in the past (mostly dirt bikes) we started with pilot jets and worked up from there? Because of the overlap. Is this different on four cylinder street bikes? Thank's for your input.
Kurt
All that I´ve read and learn since I was a kid was starting with main jets. Even with my RD 350 that I raced a couple of years the first thing was getting the correct main jet, and after trying to get the most engine power performance in all the engine power delivery. And I try to get the fatter horsepower, with plenty of low and midrange, not the maximum power form the bikes
The pilot circuit control the idle and its working range is from idle to 1/4 throttle opening, so I don´t understand that method.
Quote from: Tapartacus on August 26, 2012, 04:07:52 PM
So I turned the mixture screw IN a half turn. Blip test is solid, as idle returns normally with no hang or drop. Stock kit for 92 -
#110 Main Jet
#155 Air Pilot Jet
#42.5 Fuel Pilot Jet
from RPM. Left stock needle in, not adjustable.
Still rumbles on the deceleration at 1500 rpm,(and by stumble I mean I can feel a distinct vibration on deceleration under my ass while coming to a stop, my 89 does not do this) maybe I need to lube engine mounts, a little leery to do that though not too sure of my skill set. Anyway thats all I have. Thanks for the replies.
The specs are the same that the European OE settings, so the bike must run correctly
You have not specified 2 things:
- the mixture screw settings (leave it around 2 1/2 and 3 turns out)
- Are you diaphragms in good nick?. The symptoms (too rich, engine stumbles and vibes) are from damaged diaphragms. The good news is that the problem is cheap to repair. Watch my web, tips & fixes section
Or it is simply a dirty air filter
Hi Alf thanks for the reply. Have been to your FJ site, lots of great info there, great site. I've had the carbs apart and the diaphragms are in good "nick" Like I said, was thinking some vibration somewhere on the bike at 1500 is giving me the sensation that the engine is stumbling. When I ride down my street without a helmet on tuck my head under the fairing and listen to the engine(@ 1500 rpm) all I hear is the purr of 1188 cc's winding up. I think I must actually going crazy.
Andrew
Its very important the chain state and alignment too
Quote from: SlowOldGuy on August 26, 2012, 05:53:12 PM
When I noticed roughness during decelleration on my '93, it was frozen motor mounts.
(http://farm8.staticflickr.com/7145/6499241225_2f13949e00_z.jpg)
I just used these for the first time since doing my engine mounts some time back, very satisfying seeing the old grease pushed out followed by the fresh stuff.
Noel
Noel did you put that grease nipple there? And can you explain how greasing the collar stops the engine vibration. I just don't get it, I would understand if the mount was rubber.
Andrew
That collar needs to move freely to let the rubber at the other end of the mount (on the frame side of the mount) aqbsorb the vibration.
Do a search for greasing the motor mounts. When I first got my '93, it was silky smooth. But it gradually degraded, picking up a bad decelleration vibration. The engine felt rougher than my solid mounted '85.
I rode Chris Murphy's very low mileage '92 at a spring rally and instantly knew something was wrong with my bike. I re-synched the carbs multiple times to no avail. When I got back home, I started experimenting with the motor mounts. When I loosened them, the vibration seemed to be less. I finally tried to remove the front mounts to inspect them and possible replace them. They were frozen in place with corrosion. I came up with a tool to drive them out, cleaned and greased them up and it been back to sliky smooth since. Bob N. did a great job of documenting a similar tool and the procedure somewhere in the FILES section.
DavidR.
Quote from: SlowOldGuy on August 27, 2012, 08:40:00 PM
... Bob N. did a great job of documenting a similar tool and the procedure somewhere in the FILES section.
DavidR.
Late model motor mount service file (http://www.fjowners.com/index.php?topic=3613.0)
OR
Late model motor mount service file II (http://www.fjowners.com/index.php?topic=594.0)
Randy - RPM
Can anyone enlighten me on how to take the bolts off? I've tried with a 17mm 1/2 in socket wrench and just about pulled my bike over, those things are on tight!
Quote from: Alf on August 27, 2012, 02:02:13 AM
Quote from: yamaha fj rider on August 26, 2012, 11:29:28 PM
Quote from: Alf on August 26, 2012, 03:59:29 AM
Please, details about the Randy carb kit
By a general rule, you must set first the main jet before touching anything more
Please help my understanding. When working on jetting in the past (mostly dirt bikes) we started with pilot jets and worked up from there? Because of the overlap. Is this different on four cylinder street bikes? Thank's for your input.
Kurt
All that I´ve read and learn since I was a kid was starting with main jets. Even with my RD 350 that I raced a couple of years the first thing was getting the correct main jet, and after trying to get the most engine power performance in all the engine power delivery. And I try to get the fatter horsepower, with plenty of low and midrange, not the maximum power form the bikes
The pilot circuit control the idle and its working range is from idle to 1/4 throttle opening, so I don´t understand that method.
It sounds like you are working from full throttle down. We worked from idle up to full throttle. For desert racing we wanted a crisp low and mid range then a just little rich on the main for those long wide open sections.
Kurt
Thanks for the explanation. Everyday I learn something new :good:
Quote from: Tapartacus on August 28, 2012, 01:31:22 AM
Can anyone enlighten me on how to take the bolts off? I've tried with a 17mm 1/2 in socket wrench and just about pulled my bike over, those things are on tight!
oh ya and why do I have to take all 3 bolts off if its just the one I want to pull out?
Quote from: Tapartacus on August 27, 2012, 08:00:09 PM
Noel did you put that grease nipple there? And can you explain how greasing the collar stops the engine vibration. I just don't get it, I would understand if the mount was rubber.
Andrew
Just to add to DavidR's answer to this question. The grease nipples ( yes, I did put them in ) are only for maintenance AFTER you've done the fix as described in the Files, fitting them will not cure the problem once they are seized.
I've made lots of improvements to my bike but the difference the engine mount fix made was the best by a country mile. We are talking zero vibration from 3500 rpm up and very mild low range vibration below.
I've never known who to thank before for discovering this gem. David, thankyou, thankyou, thankyou.
Noel
Hey Noel,
You're very welcome!
Believe me, I was also extremely happy to find and correct the source of the annoying vibration.
Feels almost as good to share the information with others and see the benefit they get from it
DavidR.
Quote from: Tapartacus on August 28, 2012, 02:49:19 AM
Quote from: Tapartacus on August 28, 2012, 01:31:22 AM
Can anyone enlighten me on how to take the bolts off? I've tried with a 17mm 1/2 in socket wrench and just about pulled my bike over, those things are on tight!
oh ya and why do I have to take all 3 bolts off if its just the one I want to pull out?
Should not be that tight, sounds seized. Try heating the nuts a little? Remove all three bolts and the brackets. You will understand. Do you have an air impact or a neighbor who can help. Be careful when removing these or you can damage engine your cases (big hammer is not the answer). Hope this helps.
Kurt
Thanks Kurt, used an impact drill/driver. Looks like the bolts had been fastened with heavy duty thread locker. They came out fine with driver. After removing two of the three bolts realized why all three have to come out. The lower bolt holds the tie that holds the engine mount collar bushing on the inside of the collar. Now its just a matter of removing the engine mount collar, cleaning and lubing and reinstalling. Will report back.
Andrew
Well just got back from a long ride after removing, cleaning and re-greasing the engine mounts on my 92 and all I can say is... HOLY F$#%&*ING SH&%#@T!!!!! What a difference!! I can't believe it. I couldn't stop giggling like a little school girl every time I twisted the throttle. NO vibration in my hands which used to tingle after a hour of riding. Smooth as silk. At 60 mph and 4000 rpm it doesn't even feel like the engine is on. My problem with rumble at 1500 is almost undetectable. I will say that the most noticeable difference is at the higher rpm range but what a difference. I used to want to shift up to get rid of the vibration but now the more throttle I give it in any particular gear the smother she rolls. Anyone with a 91-93 who hasn't done this yet needs to do this NOW! Big thank you to all who suggested this and a big thank you to Bob from Ontario(good Canadian kid) for his guide and of course Pat, Randy, Kurt, DavidR, Noel. I'm just so giddy.
Andrew
Quote from: Tapartacus on September 01, 2012, 03:44:18 AM
Well just got back from a long ride after removing, cleaning and re-greasing the engine mounts on my 92 and all I can say is... HOLY F$#%&*ING SH&%#@T!!!!! What a difference!! I can't believe it. I couldn't stop giggling like a little school girl every time I twisted the throttle. NO vibration in my hands which used to tingle after a hour of riding. Smooth as silk. At 60 mph and 4000 rpm it doesn't even feel like the engine is on. My problem with rumble at 1500 is almost undetectable. I will say that the most noticeable difference is at the higher rpm range but what a difference. I used to want to shift up to get rid of the vibration but now the more throttle I give it in any particular gear the smother she rolls. Anyone with a 91-93 who hasn't done this yet needs to do this NOW! Big thank you to all who suggested this and a big thank you to Bob from Ontario(good Canadian kid) for his guide and of course Pat, Randy, Kurt, DavidR, Noel. I'm just so giddy.
Andrew
Andrew, I love this post. I have tried a number of times to get this message across to anyone that owns one of these models but I've clearly been too conservative with my language. Your description is excellent and to anyone reading this who hasn't done the mod, he's not exaggerating.
The word you used, HOLY F$#%&*ING SH&%#@T!!!!! describes the feeling perfectly. I wish I'd thought of it at the time. Perhaps it could join "kookaloo" in a list of FJ specific words.
I've said it before, this mod didn't improve the bike, it transformed it.
All Hail DavidR
Noel
If you own a 91-93 FJ this should be done once a year or follow Noel's way with the grease fittings. Bottom line it's not that hard and makes such a big improvement, like night and day. Noel next time I take mine apart grease fittings are going in. Thank's for showing the way. :good2:
Kurt
Quote from: Tapartacus on September 01, 2012, 06:44:18 PM
"problem with rumble at 1500 is almost undetectable"
Both my bikes do the same thing. My view has always been that it's just a critical rpm range at which everything chatters. It would be interesting to see if other bikes do the same thing.
DISCLAIMER: I do not ride in this rev range but occasionally find the engine under load, briefly, at those rpm and have noticed this.
The cause is only of academic interest because nobody rides at 1500 rpm, do they?
Noel
Well I have mentioned it before in another thread... about the 1500 rpm vibration and I mentioned that it does not do it on my 89, the 89 purrs like a kitten. I will say that my 89 doesn't have near the power the 92 has(not to sure why that is) so I guess there is a give and take. Someone must have tinkered with the engine in the 92 before I got it, better rings, bigger pistons space shuttle cams, not really sure because the compression is quite remarkable. Let go of the throttle at 100 kms and hour and the bike almost wants to stop, strange indeed. Maybe someone wants to enlighten my dumb ass on these matters cuz I just don't get it.
Peace
Andrew
Quote from: Tapartacus on September 16, 2012, 12:37:22 AM
Well I have mentioned it before in another thread... about the 1500 rpm vibration and I mentioned that it does not do it on my 89, the 89 purrs like a kitten. I will say that my 89 doesn't have near the power the 92 has(not to sure why that is) so I guess there is a give and take. Someone must have tinkered with the engine in the 92 before I got it, better rings, bigger pistons space shuttle cams, not really sure because the compression is quite remarkable. Let go of the throttle at 100 kms and hour and the bike almost wants to stop, strange indeed. Maybe someone wants to enlighten my dumb ass on these matters cuz I just don't get it.
Peace
Andrew
While riding today I intentionally induced the 1500 rpm shudder several times and still think it's just a critical rev range. The difference between your two bikes may be the engine mounts, solid v rubber.
As I said, both mine do exactly the same thing.
At the extreme end big marine engines have a critical rev range that if not passed through quickly can destroy the engine with vibration (resonance)
At the other end, I have a 1920's Austin 7 in my garage for an engine build. It's quite common to see these cars with a red arc on the tacho at the LOW end, somewhere around 1500 to 2000 rpm. That's where they break crankshafts, frequently, and usually when not under load.
This IS only of academic interest because of the low speed and is only occasionally encounted when too lazy to change down a gear and wouldn't be surprised if most people reading this have fallen asleep by now as it's not a problem that needs solving nor impacts on normal riding.
Noel
Well said Noel, with the new greased motor mounts I prefer riding above 3 grand anyway.
Andrew