3YF-'91 General Overhaul

Cylinder head, Barrel, Gearbox, Crank
xtzrick
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Re: 3YF-'91 General Overhaul

Post by xtzrick »

Worthlessbilly wrote: When replacing the clutch pressure plate I broke not one, but TWO of the "splines?" (the hollow tubes that seat the pressure plate nuts) on the clutch hub by over tightening.

I bought a toque wrench that had "TORQUES" in massive letters and "in/lb" much smaller underneath, so thinking I was working in ft/lbs......

I've left the broken one in for now so no picture at the moment but does anyone happen to know where could get one cheap (I'm in the UK) I struck gold before, getting one for 25 quid delivered, but now...

Would this be better off in a different type of thread, thinking about it?
DON'T use a torque wrench to tighten the clutch springs :nono:

Use a cross head screwdriver & just nip them up :thumb:

Rick
Worthlessbilly
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Re: 3YF-'91 General Overhaul

Post by Worthlessbilly »

Hmm I see. I'm starting to loose faith in my local bike shop. I went in to buy a new Phillips headed bolt and they said that they all need to be changed together and sold me 5 hex nuts that I used the wrench with. I also mentioned that pretty much my soul source of advice was here and intuition and they were quite dismissive of forums in general. Oh well lesson learned on what tool to use and, more importantly, what advice to listen to.

In the intrim, whilst I try to source a new hub, I'm very keen to try and get the engine running so will jump it of my (Engine off - Thanks in advance for your concern :shades: ) car. Now just time to hotwire and hope.....
ActionManMelb
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Re: 3YF-'91 General Overhaul

Post by ActionManMelb »

Billy, it's not rocket science!! :book:

Go back to page two of this thread...where there is a pic of the service manual. Clearly shown is the torque for the clutch hub bolts....5 ft lbs or 60 inch lbs.
That is firm hand tight with a six inch wrench.

Regarding tech info you get here... between Geoff and myself and others, you have access to 150+ years of hardcore motor engineering skills, how you use it is your choice.
"Don't worry," he said, "things could be worse ........."
So I stopped worrying and lo and behold, things did get worse!
Worthlessbilly
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Re: 3YF-'91 General Overhaul

Post by Worthlessbilly »

You're right it's not rocket science, it's Aerospace Engineering, however I'm a mere Electronic and Electrical Engineering student so what do I know. This is my first attempt at working on my first bike, and if you'd care to read my penultimate post fully, you'd see that I made a mistake after misreading in/lb for ft/lb. If you're reiterating that it was foolish, then thank you. I thought "Lesson learned re. what tool to use" and the fact that I'LL be shelling out for a replacement should have covered it.

However just for you "I AM A CUNT FOR NOT IMMEDIATELY RECOGNISING THAT I WAS APPLYING TOO MUCH TORQUE ON A PART OF MY OWN BIKE, I SHOULD HAVE STOPPED AT FIRM HAND TIGHT WITH A SIX INCH WRENCH. I WHOLEHEARTEDLY APOLOGISE FOR ANY DISTRESS CAUSED"


Regarding the tech info I recognise that there is a lot experience here, hence my online presence. I also feel that have demonstrated suitable degree of deference by; Apologising for asking too many questions, thanking the answerer of any questions I've had, and stating off the bat that I'm working outside of my experience level. It seems apparent, to me, that I have elected quite clearly how I'm going to use the information found here by; again just BEING here, following the advice I've been given TO THE LETTER, and the fact that I said I'm losing faith in my local bike shop who were reticent to listen to advice from a forum.

I hope this goes some way to ameliorate you so that I can get back to trying to find out why my bike's overheating, and you can get back to your work at CERN.
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Re: 3YF-'91 General Overhaul

Post by Worthlessbilly »

Right so, I've jumped the bike off the car and it seemed to be ticking over nicely. I've checked the oil pressure, which appears good.

MY VHT paint blistered, straight the fuck off so top job there, maybe my old oven didn't get hot enough to cure the paint properly but cosmetics can go on hold for now.

I've cleaned the housing of, and replaced, the spark plug. Now the problems: The temperature goes through the roof within a few mins, the fan kicks in at about 60% temp but to no avail. When I stop the engine the fan disengages at 50% temp, do these values sound about right?

There are a couple of very minor coolant leaks on the hoses (at the seal not cracks, all hoses have been removed and flushed out as with radiator) but I can't get new Jubilee clips until tomorrow. However these leaks would indicate , to me anyway, that the pump must be working as the hose at the top on the near side of the bike is one of the leaks.

Once the temp approached the red, I shut off the engine and had a listen. I could hear what I thought sounded like boiling liquid and found it was coming from the coolant pipes. All four of the hoses are hot. When I pinched any of the hoses (a tiny amount) the bubbling sound stopped and when I released started again. Although some coolant was lost,the indicated amount was still above minimum. I assume where I'm loosing coolant I'm also getting air ingress which is effecting the ability of the cooling system to dissipate heat. Does this sound right?

I tried to carry out a compression test, but once the bike is operating temperature I can't get the spark plug out and the pressure in without burning myself. I've got the tank off but can't really see a way of getting a better angle (I'm sat in an open air carpark when working on him). Am I missing a trick or, do I just need to buy some gloves and a couple of toughen the fuck up pills?

Finally there's brown/black smoke coming from the exhaust under quick blip of revs, but I think I'll have a think about that once I can get the bike to idle safely first.

Thanks in advance,
Billy
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Re: 3YF-'91 General Overhaul

Post by Worthlessbilly »

And last LAST LAST thing today, does anyone know if the clutch hub to an '04 TTR 600 will fit? I've found one for 20 quid.

Image

Or from a '98 YZF 400? This one's only £12.50 delivered

Image

I meant, they look the same, but t's difficult to tell just from pictures the depth and the BCD, is it standardised?

Cheers.
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Re: 3YF-'91 General Overhaul

Post by ActionManMelb »

that the pump must be working as the hose at the top on the near side of the bike is one of the leaks.
Not necessarily, the pump circulates water but does not create the overall pressure in the system.The vapour pressure of hot water does that.
The pump operates with a pressure differential of around 0.5 to 1.0 psi.

I suspect that the pump impeller has corroded to the extent that it is not capable of circulating the water adequately.
There are many other suspected causes of your problem, but the pump is number one. Pull it out and report.

P.S. Don't bite the hand that feeds you!
"Don't worry," he said, "things could be worse ........."
So I stopped worrying and lo and behold, things did get worse!
ActionManMelb
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Re: 3YF-'91 General Overhaul

Post by ActionManMelb »

Worthlessbilly wrote:And last LAST LAST thing today, does anyone know if the clutch hub to an '04 TTR 600 will fit? I've found one for 20 quid.
I meant, they look the same, but t's difficult to tell just from pictures the depth and the BCD, is it standardised?

Cheers.
Go to Partszilla.com and start researching the part number of that hub on the bikes you mention. I could do it, but they need me down at CERN.
There is a strong chance the ttr hub will fit.
I do know that there are about 50 Yamaha that use the same clutch plates (4,5 or 6 frictions), so hub interchange is a strong possiblity.
"Don't worry," he said, "things could be worse ........."
So I stopped worrying and lo and behold, things did get worse!
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Re: 3YF-'91 General Overhaul

Post by Mezo »

ActionManMelb wrote:I suspect that the pump impeller has corroded to the extent that it is not capable of circulating the water adequately.
Yes id have to agree with professor Action. :sherlock:

Nice of you to break away from your important work at CERN Dave, Doghouse had this problem also with his kettle.

Image

But hey what do we know? your not supposed to listen to blokes like us on forums. :lol:

Mezo.
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Worthlessbilly
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Re: 3YF-'91 General Overhaul

Post by Worthlessbilly »

Thank you, as you said Action man :smiley: (that's you at CERN :blum: ), it appears there are a number that will fit so I should be able to get a cheap one on order today.

The pump certainly looks nothing like Doghouses's one (thankfully) I inspected it quite closely when it was out (I'll try and dig out a photo).

If the coolant runs at such a relatively low pressure, I assume that the leaks could account for a significant pressure drop that would cause the system to function far from optimally?

In any case I'll address the leaks as they need to be done. Does anyone know if the sound I mentioned that stopped under the application of sleight hand pressure to the hoses is symptomatic of anything in particular or is it directly linked to the pressure issue that Action man mentioned.
Cheers.

To all: I thought I made it implicitly clear that I was sceptical of the advice I was being given at the bike shop NOT the information I have, thus far, been generously given here. If this was not apparent,as a result of unclear communicate on my part, then I apologise.
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