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Running Very Hot

Started by pjv, July 01, 2012, 06:17:36 PM

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racerrad8

Yep, my brain put it out right, but my fingers got it crossed up...

Lower the clip, raise the needle to enrich.

Randy - RPM
Randy - RPM

pjv

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.


andyb

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.


pjv

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.


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.

racerrad8

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
Randy - RPM

pjv

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,
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.

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?

Arnie

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

Pat Conlon

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.
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

pjv

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.

racerman_27410

i would saying doing any adjustments to the carbs requires re balancing the carbs... incl. messing with the mixture screws.



KOokaloo!


Frank

Arnie

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.