I have searched for this and dont see anything that covers my problem exactly.
89 fj12 with 32000, not very well looked after. I've had it a few weeks, trying to treat it right. I had the carbs cleaned and rejeted, swappped the crap K&N's for unipods.
The main issue now is that it's running very hot. Without leathers on, my legs get really hot and there is smoke from the crankcase breather filter (i'm trying to avoid an engine strip for that if poss).
I did a plug chop and the insulator part of the plug is bright white, that means hot right? (should be a nice tan color). So my two main potential culprits are advanced ignition timing and lean fuel mixture.
I know randy at RPM sells a beefed up oil cooler, which is now on my shopping list, but I would like to address the causes too. So I have a few q's
1) I dont see in the Haynes Manual anywhere that mentions how to check the ignition timing, am I missing something? Surely it's adjustable.
2) I'll look at the mixture settings, not too comfortable with that myself though, may take it back to the shop.
3) will the oil cooler upgrade really make much of a difference or am i just papering over the cracks with that?
Thanks again, love this board. Hopefully I'll add value at some stage.
Cheers,
Pat.
Sounds like a lean condition. How trustworthy is the person who did the jetting?
Ignition timing isn't adjustable without some minor filing or grinding or such. Metal has to move, anyhow. Possibly the black box is bringing it in too early or something, but that'd be a new one to hear about.
More cooling is rarely a bad thing, but wouldn't fix the fundamental problem.
You will get a whiter plug than you'd expect with the proper jetting, but scary white isn't good.
Sounds lean, did they give you a list of what jets they put in her?
Eliminate the obvious intake leak symptom by spraying WD40 or starting fluid in and around the intake sleeve area while the bike is running. If the RPM's increase, you have an intake leak. It *could* be as simple as the boots not being seated properly.
Dan
Thanks gents, i was hoping it was lean as opposed to worn rings (causing the smoke from the crank breather) which i think is a possibility too (but wouldn't that cause smoke from the exhaust too??). And ok, timing eliminated as a cause for now, cool.
I used to have an FJ when i lived in europe and i dont remember it feeling this hot, even riding in spain.
I think the guys that did the carbs were good (do we mention specific shops here?), but i will def get them to give me a list of what they fitted and check charts etc, and maybe ask them to re adjust.
Dan, that's a good point, while i had the tank off today i pulled the K&N's off to put the unipods on, the outside k&N's came off with zero pressure (no need for unscrewing the clamps), but i wouldn't have thought a poorley fitted k&n would pass much more air than a well fitted one? Now that I have the unipods on i'll do a plug chop again, i wasnt expecting them to make much difference, maybe well fitted uni's will richen it back up?
Thanks guys, beers on me seriously.
Quote from: pjv on July 01, 2012, 08:51:38 PM
i'll do a plug chop again, i wasn't expecting them to make much difference, maybe well fitted uni's will richen it back up?
There are others that know this stuff better than I, but it certainly seems to me that an intake leak from a poorly fitted air filter could indeed cause the bike to run lean.
If this turns out to be the case, do post it up. We have been amassing a list of why the K/N's are crap. I know some folks like them but many seem to think they are worse than stock even.
Also, the boots between the carbs and the motor should be checked. If these are leaking/ cracked, not fitted properly, then certainly the bike would run rich, at least for those cylinders where there was a leak. Did you check all 4 plugs? Are they all the same? Maybe a picture of the plug(s)?
Dan
Have the same problem with my KNs as the right out side filter is a pain to keep on . It seems to me that mine hits the top sub-frame bar right along the front bottom of the filter . Like to see how the UNI work out for you ! (popcorn)
All four plugs were the same yes, very white insulator. I will take and post pics and feedback, will be away for a few days over the 4th so maybe alittle delay.
I had the same issue with the K&N's, they just dont fit, uni's are much nicer, cheaper, and someone mentioned that the inner two k&N's may not get so much air flow as the outside two? not sure if thats bs or not, but the uni's are pairs so i would assume much more even air distribution.
I presume you have changed the oil. If it is old, dirty or is contaminated with fuel, that will cause heating issues.
The K&N filter is a poor choice for the FJ, and the notion they breathe the inner carbs more than the outer ie something I have never heard, but that does not seem plausible.
Also, a loose air filter will not cause a lean condition. You need to find out what jets (all of them) and se if they set the needle height.
Once you have the jet info, I can point you in the right direction.
Randy - RPM
Do you have adjustable needles? If you changed to a low restriction air filter, then the stock needle position will be lean. Shim the needles about 0.02 inches with small washers.
Smoke will escape from the crankcase breather. It's HOT in there and there is as much air moving below the pistons as there is above them. That's why the breather is plumbed into the airbox, to burn the oil smoke rather than allow it to vent directly to atmosphere.
DavidR.
ok, some updates. Really appreciate your help folks. Quick Recap - Engine running hot, white plugs, smoke from crank breather.
1) have road tested with the uni pod filters, they fit much better than the K&N's and actually stay on. Thanks RPM.
(http://fjowners.com/gallery/3/2557_17_07_12_9_21_21_0.jpeg)
2) engine still runs hot (white plug pic)
(http://fjowners.com/gallery/3/2557_17_07_12_9_19_19_0.jpeg)
3) the carbs were in bad shape, very dirty clogged jets etc, the dealer fitted a new dynojet stage 3 kit, with 118 main jets, the others are as per the kit chart (I wish I'd read Randy's "Kit" Rant before that). I called the tech and he suggested raising the jets one more slot (to the 3rd from the top), to richen the mixture (he also strongly suggested converting everything back to the standard air box and jetting for general street use, i agree, that will be longer term goal, just want to not have it melt down for now).
(http://fjowners.com/gallery/3/2557_17_07_12_1_41_37.jpeg)
4) The type of riding i was doing to get this hot was nowhere near 3/4 or WOT, can't really do that in my suburb, so it was mostly slower speed 1/4 throttle type riding, so i dont think the white plugs are an accurate indication of the main jet settings but more the pilot air screw/jets? I think they need to be richened up. Probably that and one click on the needle. Or is that nonsense?
(http://fjowners.com/gallery/3/2557_17_07_12_9_21_23_2.jpeg)
5) the smoke from the breather still bothers me, but i did a cheapo compression test and i got 170,160,160,160 psi on a cold engine (#1 had a little oil in it from a hot wet test the night before, (after i gave myself a heart attack and did the test without a WOT, i only got 100,100,100,100 psi at zero throttle on a hot engine and went to bed very depressed). So i think the rings / top end is good. The gauge climbed 30, 60, 90 150 psi kind of thing as i cranked the engine, hopefully that's ok. DavidR – thanks for the note re feeding the smoke back into the airbox, but some folks see this smoke as a need for a leakdown test, which would be tricky for me to get done.
6) engine oil was recently changed.
I think that's it. Thanks everyone.
Please take another picture of the plug and get the light source at the tip, the outer ring needs to be looked at as well.
If he put the clips at the top slot, that is the leanest setting. I am not sure about the DJ kit, but the stock needles that I supply with the adjustable slots start at the center slot. Meaning the center slot is stock and lowering the needle will enrich the circuit. If the DJ needles are the same you started off lean and still have not even gotten to the stock location.
Randy - RPM
Thanks Randy. will retake the plug pic.
Here are the needle options.
(http://fjowners.com/gallery/3/2557_17_07_12_2_47_10.jpeg)
Quote from: racerrad8 on July 17, 2012, 03:04:40 PM
lowering the needle will enrich the circuit.
I think that is a typo, or I haven't had enough beer yet :drinks:
Check to make sure whoever installed the carb kit put the stock plastic spacer under the clip of the DJ needle.
If he didn't re-use the stock spacer, it will be extremely lean!
Pretty sure Randy meant to type "lowering the CLIP will enrich the circuit"
DavidR.
Yep, my brain put it out right, but my fingers got it crossed up...
Lower the clip, raise the needle to enrich.
Randy - RPM
thanks folks.
I'll check re the spacers, but if they were not re used, (and i would assume are now lost), can i compensate with raising the needle a click or two? Or do they have to be replaced. Hopefully they are there.
Replying to the recap'ing post:
1- Yup. Beat the hell out of the K&N's, don't they?
2- Interestingly, in that picture it looks like your timing is just about spot on to me. To properly read the insulator, it needs to be removed from the housing, or you'll need a good magnifying glass and lighting. WOT use is really only visible waaay up where the insulator joins with the casing. Something about cylinder pressure pushing the witness marks farther up the plug with heavier throttle use. The area around the electrode is useful for idle quality and obvious issues (broken bits, melted piston spatters, etc).
3- Having an airbox or not isn't going to change operating temperature significantly at all. You'll gain a bit of quietness and trade some of your current top-end for some power low in the rev band if you refit the airbox. The noise is addictive to my ears, but some people are too stupid to simply go up a tooth on the rear sprocket don't like the loss at the lower end of the tach. Further, I would argue that you never, ever, ever ever tune an engine by reducing air going in. You tune by adding fuel, and get as much air in as possible. Airboxes are for the weak!
4- Bull! You can go WOT right off idle in 5th without going much over 25mph! But with that said, you're not going to be able to test the main jet circuits until you're seeing more than 6krpm on the tach and at WOT. That needs checked FIRST when you're jetting stuff, but imo the DJ118 should be close enough for the time being. If the heat of summer is as oppressive for you as it's been here, it'd not surprise me at all if it was a bit on the rich side, even.
5- Your compression numbers are excellent. Smoke from the breather is going to happen, that's why it's routed into the intake by the factory, as it'd look bad if their new bikes were having oil vapor pouring out! The proper answer for you is coming up with a way to trap that oil and return it to the crankcase. I'm just going quickly over things, but if you've got the breather just vented to atmosphere or at most with a little K&N type filter on the end of it, it's gonna smoke like hell, and it's normal. Fill the thing with steel wool and/or add about 4' of hose and run it well up into the tailsection of the bike, and the smoking will drop hugely. It's just oil that's been turned to mist, no worries. The big danger is that you'll eventually run out of oil, but it shouldn't be anything like bad enough to be a problem.
Also on K&N's and air leaks: An air leak on the filter side of the carbs is not going to cause any leanness, as there's only a tiny amount of resistance from the filter to flow and thus little to no vacuum out there. Between the carb and the intake valve is a different story entirely. Compared on a dragstrip on back-to-back laps the difference between K&N's and no filter at all, and it wasn't significant at all. The bigger problem of an air leak from a poorly-fit filter would be unfiltered (read: gritty) air going through the engine, and doing ugly things to the valve seal/seat on that cylinder.
you guys freaking rock.
1) - The unipods do look like something out of the bath tub (who cares), but i'm lovin them.
2) - plug color - interesting, i've always gone by this picture, it's been along time but i cant remember ever seeing plugs as white as mine are now.
(http://fjowners.com/gallery/3/2557_17_07_12_9_21_22_1.jpeg)
3) I took the plunge the other night, after a beer, and tweaked the pilot mixture screws (out half a turn) and the needles, (raised the needles by one slot). The oem spacers are still in place. I rode to work this morning and it seemed less hesitant and more responsive. I was whooping it up inside my helmet. Though it might just have been the joy of not effing it up. I'll do another, better plug chop and share the pic. hopefully i've not over richened.
4) undrstood, it's the over 6k with the silly loud pipes i have on it, again i'll try and do a better chop.
5) very reassuring, thanks, great info.
Quote from: pjv on July 20, 2012, 10:34:08 AM
2) - plug color - interesting, i've always gone by this picture, it's been along time but i cant remember ever seeing plugs as white as mine are now.
You, have to remember the coils spark two plugs on each cycle. One is on compression and the other is on the exhaust stroke. The secondary fire of the plug on the exhaust stroke does two things.
1) Burns any unburned fuel from the exhaust.
2) Cleans the plug.
The cleaning of the plug is what is making your plugs whiter than you are used to seeing.
Randy - RPM
ok, an update. recap 2 - all pilot screws turned out to 3.5 turns each, and needles raised one click (third from top. My reasoning was to richen two circuits at a time, as most of my riding was low throttle opening.
I rode from boston to the cape and back,
(http://fjowners.com/gallery/3/2557_23_07_12_12_35_16.jpeg) i thought she was awesome, very responsive, pulled from 80mph to 115 in what seemed like a second (only for second), felt great. I dont "feel" the heat anymore, but i haven't had a chance to do a proper plug chop. There were several miles from the highway to the house, and this is what the plugs looked like. Plug 2 is the scariest, i had noticed this soot once before, BEFORE i messed with anything.
(http://fjowners.com/gallery/3/2557_23_07_12_12_18_02.jpeg)
left to right
1 looks hot
2 is sooty
3 looks rich?
4 looks good?
Is this even a valid test if i didnt do a "proper" plug chop?
How badly have I effed this up?
pjv,
Well, without a "proper" plug chop, (new plugs, steady running for minimum 3 minutes, pull clutch - hit kill switch - read plugs) its difficult to read too much from your pic.
However, my impression is that the only concern you may have is #2. You may want to still richen the others slightly, but at this point I'd check the float height carefully and make sure the valves are all within spec.
So, now that you're this close its time to re-check valves, float heights, sync carbs, and then put in new plugs and go for a ride and do a plug chop as you arrive back home.
Arnie
You have sync'ed the carbs, right?
At this point I would go ahead and check the valve clearances.
With your excellent compression numbers I would rule out #2 being oil fouled.
thanks guys. BTW, i have donated to the site, so i'm not freeloading anymore.
1) The carbs were balanced when they were cleaned/rejetted by the dealer. I'm not sure what changes cause the need for a rebalance, but if what i've done could have done that, then i guess i'm off to buy a set of gauges!
2) re the valve clearances causing the soot, i'm assuming they've not been done for a long time, so the valves would not be opening far enough right? I have not checked the possible electrical causes for the soot (leads / coils etc), will do that too, but is that ever really the cause of this?
thanks again.
i would saying doing any adjustments to the carbs requires re balancing the carbs... incl. messing with the mixture screws.
KOokaloo!
Frank
Quote from: racerman_27410 on July 24, 2012, 04:27:01 PM
i would saying doing any adjustments to the carbs requires re balancing the carbs... incl. messing with the mixture screws.
Frank
+1
In fact, I think the rule should be, "If you take off the tank, balance the carbs".
It only takes a couple of minutes and can make a world of difference.