It's a ping! Or is it a knock?

[Burns]

I mean no offense Leopard and I think it is great that you want to learn to service your own motorcycle, but frankly from your (often contradictory) comments I conclude that the level of your basic technical knowledge suggests that you will be better off taking your bike to a professional mechanic.  Motorcycles are a bit like airplanes in their unforgiving response to inattention to details.  You simply lack the knowledge of what those details are and the potential costs of inattention to them.

Things like driving with a loose drain plug can cost you your life.

On the bright side, this is a very robustly constructed motor and it is unlikely that you have seriously injured it.  Also, it has a lot of naturally occurring mechanical noises and the pistons are perhaps the least likely source of what you are hearing.

Perhaps someone here will know a shop in your area that they can recommend.

[Mark Olson]

put a new battery in it and see if it starts normally.

fj's make noise when hot or cold , that is just a fact.

take it out and run the rpm's up in the 6-8k range . watch for smoke out the pipes.

report back.

[Burns]

put a new battery in it and see if it starts normally.

fj's make noise when hot or cold , that is just a fact.

take it out and run the rpm's up in the 6-8k range . watch for smoke out the pipes.

report back.

This is the "throw money at it" approach with which I respectfully, but totally, disagree.

If you are determined to tackle this challenge Leopard, it is your money and your life. Everybody starts from zero one way or another. But I strongly suggest that you approach the problem systematically.

The first thing you should buy is a shop manual.  Then scan it for basic concepts, paying attention to "trouble shooting"

Your battery MAY be bad (or you could have left a switch on, or you may have a charging problem or . . .) but make that determination BEFORE you buy a new one. Continue that approach, isolate and eliminate possible problems one at a time.

I still think you will be time and money ahead getting your bike squared away by somebody who is not doing everything for the first time, and then learning how to maintain it, but see paragraph 2.

Either way you go, best of luck, sincerely, and may you have many years of motorcycle enjoyment - both on the road and in the garage.

[theLeopard]

i'll cool this one down quick.
battery is 2months new.

ran a compression check and I need to rering all 4 cylinders, none of them even meet minimum.
waiting for a list of parts I need to purchase, Randy's fairly well slammed this week so if you guys know what to buy help a brother out.

Just the essentials: rings, gaskets, and other rubbers.

[simi_ed]

You need rings?  Maybe it's valves?  Did you ever check valve clearances?  You know this is not a job for a rookie, right? Did you read my last post on your issue? (http://www.fjowners.com/index.php?topic=11930.msg118506#msg118506)

Out of hand, I'd say that anyone that loses a drain plug and dumps their oilpan contents is not qualified to do an engine rebuild.  Please let us know how you fair.  

[Mark Olson]

put a new battery in it and see if it starts normally.

fj's make noise when hot or cold , that is just a fact.

take it out and run the rpm's up in the 6-8k range . watch for smoke out the pipes.

report back.

This is the "throw money at it" approach with which I respectfully, but totally, disagree.

If you are determined to tackle this challenge Leopard, it is your money and your life. Everybody starts from zero one way or another. But I strongly suggest that you approach the problem systematically.

The first thing you should buy is a shop manual.  Then scan it for basic concepts, paying attention to "trouble shooting"

Your battery MAY be bad (or you could have left a switch on, or you may have a charging problem or . . .) but make that determination BEFORE you buy a new one. Continue that approach, isolate and eliminate possible problems one at a time.

upon rereading the post I see the battery is only 2 months old. 
the starting problem is not that the engine will not spin from the starter , but it does not fire up.
It appears the choke was not in play and caused this problem.

FYI... to properly start the fj when cold , you must pull choke to full on position then push the starter button without any throttle applied.
the fj is quite cold blooded and will take several minutes to warm up . As the rpms rise up as it gets warmer , slowly push choke in to maintain a reasonable rpm of 2500 then all the way in and it should idle around 1000 rpm. once again this takes some time.

If your fj will start on this procedure then it is normal.

the only part I will throw at an fj is a new battery when starting problems exist.  They will do some weird stuff .

still waiting to hear how it ran and if any smoke on acceleration or deceleration , please wind it up into the 6k-8k range.
is it using oil ?

Your low compression may be the result of stuck rings , and some spirited riding may remedy the problem.

report in this post so I don't have to search everytime and others can follow the thread as to what has been done already.

[Burns]

"ran a compression check and I need to rering all 4 cylinders"

were you WOT during the test?
Did you run it both dry and wet?
Do you understand what I am asking?

[theLeopard]

don't understand WOT, mate; but I ran the test dry.
have to pull the thing apart anyway if results change wet so i'm just gonna replace the rubbers then run another compression check.
crossing my fingers hoping for the best. I rode it to school today and it idled steady and didn't leak any fuel out the overflow so i'm hopeful it's fairly healthy and just needs new rubbers.

[Burns]

"WOT" is wide open throttle.

If the carbs are mounted, the slides have to be fully open while you spin the motor or you will get inaccurate (low) numbers.

[theLeopard]

upon rereading the post I see the battery is only 2 months old. 
the starting problem is not that the engine will not spin from the starter , but it does not fire up.
It appears the choke was not in play and caused this problem.

correct. I jumped the gun a bit when I posted here, I hadn't properly diagnosed much of anything when I reported starting problems.
the screw fell off the choke cable-bracket on the post so I couldn't use my choke. works and starts well enough now, a slight flick of the throttle is usually all it needs.

still waiting to hear how it ran and if any smoke on acceleration or deceleration , please wind it up into the 6k-8k range.
is it using oil ?

Your low compression may be the result of stuck rings , and some spirited riding may remedy the problem.

report in this post so I don't have to search everytime and others can follow the thread as to what has been done already.

I'm a bit cautious about pushing the bike that hard right now, it's been through quite a lot recently and I already know the rings are originals (from 1992).
Just seems like everything points to bad rings and/or rusted cylinders. The cams are spotless so i'm thinking it's just the rubbers.

Rode it to class today and it was healthy, didn't push past 4000 and didn't notice any overflow, idle was normal, started normal, noticed some fluid on my right front-fork joint so I cleaned it and will check it tomorrow.
It's just aged; needs some TLC. Trying to avoid breaking it while I service it back to health.
Gonna piss up a rope if it dies on me I swear to god but my stress level is returning to normal. Long week, not just the bike either  

[theLeopard]

yeah, I gunned it.
I'll run them again before I purchase parts but i'm confident the numbers are as accurate as the gauge I purchased.

slides have to be open

please clarify, I simply pulled off the tank and opened the throttle.

[Firehawk068]

slides have to be open

please clarify, I simply pulled off the tank and opened the throttle.

The CV carbs on our Fjs have a slide that operates via engine speed/load, that opens and closes to increase or decrease the volume of air flowing through the carburetor, trying to maintain a "Constant Velocity" of air speed throughout the engine operating range.

If you take the air-box off, and look down inside the carb, you will see the slide blocking the air path through the carburetor.
Air entering the engine has to go past this slide valve, and also past the butterfly valve that you control with your twist-throttle.

The slide valve is operated by vacuum, and has a large rubber diaphragm attached to the top of it. Underneath the big square-ish cap with 4 screws, on top of each carburetor is the vacuum chamber. There is also a spring under the cap that holds the slide closed until there is enough vacuum to open the slide.
The slide also has a tapered needle attached to the bottom of it, that plugs a hole where fuel comes out.....................The more the slide opens, the more it unplugs this hole, and the more fuel is let out....................It directly corresponds to the volume of air flowing through the carburetor.

At cranking speed, when you are trying to do your compression readings, the vacuum slides are mostly closed and not allowing much volume of air to enter the engine.
This will greatly affect the readings............................
Less volume of air = less air getting compressed = less readings

Engine temperature will also affect the readings.............Warm-vs-Cold readings will be different............A cold engine will most often have lower readings than a warmed up engine.

In order to get an accurate compression reading, the vacuum slide must be propped open(You won't be able to do this without removing the air-box), and the butterfly valve held open with your throttle hand..................
You can also remove the 4 screws that hold the cap on top of the carburetor, and simply remove the spring, the diaphragm, and slide completely..........(this eliminates the need to remove the air-box, but be careful the screws are JIS, and will strip easily with a regular phillips screwdriver) Doing this will also allow you to inspect the rubber diaphragm for pinholes(very common on older, high mileage machines) that could affect proper carb operation.
Or you could even loosen the 4 clamps on the engine intake rubber boots, and pop the whole rack of 4 carbs off the engine altogether..................then you wouldn't have to worry about propping open the slides, or even twisting the butterfly valves open either.....................And inspect the rubber intake boots for cracks(also common on older,high mileage engines)
Doing your compression readings with the carbs off is as wide-open throttle as you could possibly get!

Hope this helps you a little 

[FJ_Hooligan]

At cranking speed, the slide cutout allows plenty of air through as long as you hold the throttle wide open.  Best readings would be taken with carbs removed, but it's not really necessary.

[Bones]

I'm  a bit cautious about pushing the bike that hard right now, it's been through quite a lot recently and I already know the rings are originals (from 1992).
Just seems like everything points to bad rings and/or rusted cylinders. The cams are spotless so i'm thinking it's just the rubbers.





What's the mileage reading, these bikes can do some high mileages before they need rebuilding. No offence mate, but you obviously don't have a clue at all with some of your diagnosis of symptoms.

Save your money buying parts that YOU think it needs and let someone who knows what their doing check it out for you.

[racerrad8]

At cranking speed, the slide cutout allows plenty of air through as long as you hold the throttle wide open.  Best readings would be taken with carbs removed, but it's not really necessary.

+1

If you have flat bottom slide 1100 carbs, then you might see some restriction and need to raise the slide(s)

Randy - RPM