New member, New bike and i mighta broken it already

[Thunderdome74]

Hi everyone

I am new to the site an Cbx's, so please let me know if thisis in the wrong place.

So after years of dithering a cbx came into my possesion for a goodish price , although she had been standing for many years.
The guy i bought it from said he had it running and had gone thorugh the carbs... and all she needs is a battery

Well in the interests of brevity:
She was running on 4 cylinders, Clutch rumble, but sounding good
I bought yamalube and let it sit in the bowls for about 8 hours then drained the bowels.
Ran it again and no 5 wasn't firing and there was some fuel coming out the RHS (6 into 2 pipes)
Left it for the evening (tap off)

Came this morning (and in a moment of idiocy) hit the starter, It just clicked
(there might have been a mili second of swing but not much at all)
Did it again and it clicked but A bit of fuelcame out the right exhaust side.
Then she fired into life (still on 5 tho)
I rekon about 200 odd cc of fuel might come out

So i realise this question is like "how long is a piece of string" but having read what i could about Hydrolock, i was hoping for some opinions
There is no knocking or smoke or undue noises(other than what was before due to unsynching and 5 cylinders) and after i fitted new plugs today she sounds pretty great (still on 5 tho)

Is there any way to check for damage to the rods>?
Compression test?

With the above scenario, are the rods usually bent... ?

Sorry as i know this might have been covered alot , but i havn't been able to find a similar scenario

Any help will be greatly appreciate
Thanks(a very worrried new member)
Thor

[cross]

Welcome and congratulations on your X!
Hydro locking was issues on earlier models and usually the rod would go out through the case. In your case, it is possible that carbs need to be cleaned completely so they need to be removed, disassembled and all passages carefully cleaned. We all went through this with our bikes that were sitting for extended amount of time. There should also not be fuel coming out of the exhaust and certainly not that much.
Additionally, spark plug cables and coils should be checked as well but first do the carbs properly. There is plenty information on here about it, just search for it.
What year is your bike and how long has it been sitting? Post some pics

Sasha

[Thunderdome74]

Cheers for that

Its a 79. But i wasnt using the tank , but a small fuel bottle (if you are refering to the tap issue)
I would guess it's been standing for about 5 years judging by the condition of the tank (very rusted)
I tired the Yamalube in the hopes all 6 would be running, but there is always one isn't there

I will be dropping the carbs at some stage but if you go that far, 1 bolt and the engine is out for spraying... then might as well do the frame...

I was hoping to get her running for roadworthy without removing carbs, but it needs to be done.
(also there are a couple of other projetcs that need finishing first...69 cb750 and a 77gl2000)

The bike looks to be very original, even down to the spark plug lead holders.. but the usual rust etc

Oh yeah, i put some new plugs in and was getting a Very weak spark (new batt) on all coils?
I plan on cleaning all the connections... is there anything specifically i need to check?

I have been browsing this site for a few days now, it's fantastic



Tx

Thor

[Thunderdome74]

I will also need to ditch the carb drain setup and put some individule drain hoses on.

Much to learn still

[Larry Zimmer]

Hi, Thor,

Congrats on your 'find'. I am FAR from being an expert. However, I will suggest that you remove the cylinder head for inspection, possibly valve 'job' and new viton valve seals, if you are removing carbs and removing engine from frame. You will have done 90% of the work once you remove the engine. (You will, also, be able to confirm any hydrolock at that point.) Might, then,remove the cylinder block for cylinder bore inspection/honing; and, perhaps, new piston rings. Sounds like more work and expense. However, not that much more if you are as far along as you mention. And, then, you KNOW! Hopefully, some of our CBX 'masters' will have some worthy advice to contribute.

Again, welcome to the fraternity. Looking forward to your adventures.

[Mouse]

To the group Thor.

[letxbruce]

It's possible to bend a rod due to hydrolock without drastic results or loud noises. It happened to mine. A possible clue is fuel spitting out the exhaust. The float valve might not be seating. Before tearing the engine apart I would remove the fuel supply and take the plug out of the dead cylinder and spin the engine. Watch for fuel spitting out of the plug hole. Then do a compression test on the dead cylinder. If good, then look at spark, then carb.

[Thunderdome74]

Hi Everyone

Thanks for the replies.

Bit of a crossroads about what to do.
I fired it up again (making sure there was no Fuel in her)
She is running well on 5 and the side the fuel came out of (right hand side) is firing and i am not hearing any noises.
She is idling nicely , but i am unable to distinguish if there is any noises coming from the RHS as i have the clutch rumble due to out of synch

No 3 is dead. Swopped plugs and checked , I am getting spark.
I think it might be the idle jets , so the carb will need to come out regardless

I will try today to run her with the Choke on and see if No 3 comes to life.


About the HYDRO locking.My planned steps
Please let me know if i am missing something/being stupid etc

So the engine will come out, but before that
001 i want to do a Comp test.
Will this tell me if there is a bent rod?

002 Then i want to do the TDC measurement
(this confuses the hell outta me as it seems very inaccurate ) as there are variables are there not?
IE any piece of Carbon on top of the piston will effect reading, no?
Incorrect exact placement of measuring tool will also give differing measurements?
As we might be talking thousands of an inch i would like to know how anyone gets an accurate measurement?

I was thinking about making a tool with the same thread as the plugs with a thin movable UP/DOWN Slide in the middle which would them screw into the plug hole and the
movable piece could then be measured by the piston pushing it out at TDC, but to my mind any differences in the tightening of the tool in the thread would cause
variances on the measurement?

003 Head offPossibly if i get any reading other than normal/same across the board?
Other than visually inspecting is there any accurate way to measure the rods with the head off?
(i would then do the valve stem seals/possibly lapping)


Steps 001-003 , am i missing anything?
Its a fairly high mileage bike (40k miles) but i have spoken to the PO and he said the oil was changed very regularly and he has never had a days problem, no smoke ever etc

Thanks again

Thor

[steve murdoch icoa #5322]

I think most of what Bruce mentioned is good advice.
All the variables you mentioned on the TDC length could be true and a compression test might not reveal bad numbers if the rod is only bent slightly.
Of course it would show up at higher rpms.
Before taking the engine apart i would do a complete clean of the carbs. The Mike Nixon book is a great guide.
Have a read through this thread.... a lot of similarities.
viewtopic.php?f=25&t=6893

Welcome to the site, Thor.

[daves79x]

Welcome! Seems you are diving right in and doing your homework. A rod only has to bend very slightly for it to contact the crank, and you'd hear it. However, even a very slightly bent rod would yield noticeably lower compression on that cylinder. Problem is, you have no baseline compression numbers to compare to. Measuring each piston pair through the spark plug hole is OK - it will show you any significant height difference. If the engine is not tapping, I would get the carbs completely rebuilt (lots of info here on that), reinstall them and get the bike running properly as is. Then you can evaluate the whole bike. You may indeed end up wanting to do the head at least, and if you do, visually looking at the piston pairs as they come to TDC will tell you if you bent a rod. Get the bike running properly, get a compression baseline, and if you have one cylinder consistently low, pull the head and investigate. If all is well, run it.

Dave

[Thunderdome74]

Thank you all for the replies.
Fully agree in getting the engine running and asess.
Thanks. I have bought the cbx carb book (I think it will be quite helpful on the gl1000 carbs as well as they look similar)

[Thunderdome74]

Ok, hopefully this is something

125 125 130 130 130 130 Comp readings across the board
Cold engine/throttle wide open
Bike has been sat for i dont know how long, so i am hoping this will improve when she is running a bit

67000km on the clock/no idea if she was ever opened but it doesn't look like it as the bolts are pristine

Also when the plugs are out and the engine is swung, all i hear is the starter motor, no noise at all

So unless anyone disagrees i think i'm going to clean the carbs and run it?

[daves79x]

Absolutely, have at it. Just make sure you're ready for a challenging job with the carbs.

Dave

[Thunderdome74]

Thanks Dave

Yeah, it took me about 8 tries to finally get the Goldwing carbs dialled in, but i learnt alot so hopefully this wont be too bad.
(the goldwing i had carb removal down to 4 minutes), i suspect the CBX will be at minimum 4 hours, lol
so i want to get it righ first timas much as possible.

I have Mike Nixons book coming , so much studying to be done.

I will let you guysknow how it come out

Thanks agin
Thor

[steve murdoch icoa #5322]

Could be they just need cleaning but if you need parts you can get quality carb kits from Randakk.
https://www.randakks.com/randakks-maste ... -kits.html