Valve Stem Seal Replacement Without Removing Head

[fastbob]

Read through most of the updates but confused as to what your doing with regards pistons/rings/bores, sorry if i missed something but if your just putting back together what you took apart there is likely to be little to no improvement in compression ??

 

I was thinking the very same thing , I would have thought that a light honeing of the bores was worth considering having come this far . Again , sorry if I missed something as well .

[leener]

Cheers for all the input, guys.

I'm a bit strapped for cash, even though I'm on what most people would call a nice comfy salary - thanks to CMS and my ex, who is hell bent on financially destroying me. So, forking out for anything is a major task. I will take it all apart again, because I am not finished. I probably am screwing up the new head gasket by taking the head off again.

I wanted to 'quickly' put the engine back together so see if I had better compression, which I did, and instead of 50psi, I get 100. Which is still too low. YouTube videos show the same engine getting 180+ on a cold engine.

I rigged up the starter to a battery, and just cranked it up with the compression tester tightly inserted into each cylinder.

Cam chain is back on, cams lined up exactly as they came off, timing is spot on, and engine is literally just sat on a pallet.

100 psi on each cylinder, with very little change if I add a little bit of oil down the park plug well.

I had done all of the end gap measurements and checked the piston, and bore diameters. According to the Haynes manual, everything was spot on.

I have the head tightened on to spec, and the timing is set the same as it was (used photos to make sure).

And the valves aren't leaking, after the top end rebuild.

I'm at a loss. I could strip it down again and get the thing re-surfaced, honed, and anything else I need to do to it (when I have the cash).

Or, I could sell the engine components off to fund a replacement engine.

All in all, doing this has taught me a lot about mechanics, and combustion engines, techniques, and what mistakes can happen. But, I still have a lot to learn.

[megawatt]

Can you get the engine to someone with a leakdown tester and a compressor.

If only a compressor, you can borrow my tester.

Gimme a bell for a chat?

[Bender]

Have you got anything else to put the compression tester into to make sure it's OK, you seem to have consistent pressure, the chances of every cylinder being down the same amount is very slim, unless you put a thicker headgasket on to lower compression to put a turbo on it.

[Mr Fro]

Before you totally chateau your pants and rip it all apart again, are you sure the gauge is reading correctly?

[SlowBusa]

When you say its on a pallet does the starter crank the same speed as when its in the bike?

I used this method before and the starter cranked really slow....Also when I used this method years ago the engine didnt have oil in it so that affected compression too...........presumably because the rings were not sealing properly because the oil wasnt coming from below.

I dont care what anyone says but head gaskets have been a bain in my life and re-using one Never works the same as the first time

[leener]

Can you get the engine to someone with a leakdown tester and a compressor.

If only a compressor, you can borrow my tester.

Gimme a bell for a chat?

 

Thanks, guys.

I'll try to give you a call soon as I can (no credit on the phone).

I'd really appreciate you letting me borrow your tester.

 

Before you totally chateau your pants and rip it all apart again, are you sure the gauge is reading correctly?

 

The answer to that question is no. The thought crossed my mind that the gauge may be faulty. I haven't got another to test with, at the moment.

 

When you say its on a pallet does the starter crank the same speed as when its in the bike?

 

Yup, it cranks at high speed. Although, was a very frightening moment when I'm already desperate for the toilet, and huge sparks jump out at me.

I had a fully charged battery on the go to do it. The first battery was low on charge, so didn't quite have the power to turn the motor after a few goes.

My poor hands are cut to ribbons from that gasket. I was cleaning it with a cloth rather thoroughly!

There is very little oil in the engine, so should I try adding some to see if that helps?

I need to find out if the compression tester is duff.

I'm really hoping to get this engine running soon.

[SlowBusa]

There is very little oil in the engine, so should I try adding some to see if that helps?

I need to find out if the compression tester is duff.

 

Of course you wont have much oil in there because you pulled it apart?

It cant hurt

Years ago I was cranking a motor a lot and had similar PSI results till I put the oil cooler on and added Oil , if memory serves me right the PSI jumped up to decent pressure

Its worth a go

My real thoughts are about your (now used) head gasket

Are you dipping the compression tester thread in oil before installing it?

[SlowBusa]

With thought a "dry" engine is not going to seal properly and may cause damage

metal on metal without lube as you can appreciate isnt good

[leener]

Are you dipping the compression tester thread in oil before installing it?

With thought a "dry" engine is not going to seal properly and may cause damage

metal on metal without lube as you can appreciate isnt good

 

There is a small amount of oil in the engine, but not a great deal, at all. I will give it some more oil and try again. My worry is that it is just cranking, so no oil pump is running, nothing else connected. I just have the head on, so oil can't get pumped around.

And, I didn't have any oil on the compression tester. This might help! Cheers.

I want to get round to it asap, and now the clocks have gone forward, I may just have a chance to get on with it after work.

[SlowBusa]

What you want is enough oil so the piston skirts dip into it and oil gets on the barrels below the rings

It may make no difference but its worth doing

[leener]

What you want is enough oil so the piston skirts dip into it and oil gets on the barrels below the rings

It may make no difference but its worth doing

 

I'll have a go hopefully later tonight. I need to pop the engine upside down, anyway... I forgot to put the black, plastic, tube thingy back in the sump, before I bolted it up. That may be a problem.

Then add more oil, whip it back over, and try again. It's likely that the tester is not 100%, since it has been mashed around in the back of my car quite a lot.

[megawatt]

Gimme a bell after 1930 mate. Message your address.

[megawatt]

Black plastic tube thingy??? Is that the oil pick up from the sump to the pump? May be rather essential.

[leener]

Black plastic tube thingy??? Is that the oil pick up from the sump to the pump? May be rather essential.

 

Is definitely the oil pickup feed.

Many thanks for the chat, last night. I now have a few things to try, including a leak-down test, which I can easily do, after I make a suitable feed into the cylinder from a compressor.

I am suspicious of the compression tester being faulty, so will look to get another. It is unusual that I have exactly, or close to 100psi on each cylinder.

First up, I need a basic test to listen for leaks in each cylinder. I will attack the compression tester to get the adapter and get the tube separated from the gauge to attach my air compressor, which should bring in enough air to the cylinders to hear any escaping, and not too much as to crank the engine.

Then, set cylinder one to TDC, tightly screw in the adapter into cylinder one, and start the compressor.

The cylinder, now set at TDC, should have a perfect seal, because both the intake and exhaust valves should be completely closed.

Any leaks should be noticeable, as the sound of air will be louder from either exhaust ports or intake ports, assuming both sides aren't leaking.

I'll also be able to hear in the crank case if the piston rings are leaking significantly.

Then repeat for the other two cylinders.

But, the most important thing to do first is to get that oil feed tube back in the sump before I kill my engine.

I'm hoping to get onto this asap this week and will post some updates. I have a few other things to check and make sure I have set right, including adding oil to the engine.

Again, big thanks to megawatt for taking time out of his day to pass on priceless knowledge and tips that I will benefit for a lifetime, and for the offer to help me with the engine in person (if I my car is capable of making the trip).

Your advice has taught me more than I ever learnt at school - and that is no exaggeration.

More posts to follow...

[SlowBusa]

Im wondering if you have same tester to me?

Ive a Draper Compression tester that Im suspicious of

I wouldnt care but my old £12 one was more accurate

 

[leener]

Im wondering if you have same tester to me?

 

The very same one as in that pic, except that my needle isn't even on zero, when released. I'm hoping to have this sussed out with a leak-down test and buy or borrow a compression tester from somewhere.

I brought mine from a local Motaparts shop. Same place where I purchased my torx set, which snapped during trying to remove the cylinder head bolts, the first time.

There's so many on eBay, but I think I need to invest in the proper kit.

[Bianco2564]

You shouldnt be cranking it without any oil in,you will damge the crank and cam bearings,these will be the first to suffer.

If you lubed the pistons and bores properly during assembly,these should be ok for a short burst of cranking.

If that is the oil pick up pipe,dont try cranking any more until that is back in place,you will fk your engine.

Its worth priming the oil pump while its upside down aswell so it draws the oil up right away.

When you are carrying out the comp test,do you continue cranking until the pressure stops rising,it will take a few revolutions of the engine to achieve full pressure.

You have got a one way valve (usually a schrader),ie when you stop cranking the pressure remains at 100 psi or whatever it achieves and you have to press a button to release it?

[SlowBusa]

Well...think of that as a good thing and hopefully your getting more PSI's than the tester shows

I can do multiple tests ....unscrewing it every time and get different results each time (waste of £25!)

Im NOT impressed with this tester and wish I'd saved my old one now

The thing that bothers me is the way the tester thread goes into the plug holes........unevenly

[leener]

You shouldnt be cranking it without any oil in,you will damge the crank and cam bearings,these will be the first to suffer.

 

That is my biggest worry, which is why I did not spend very long at all cranking it. I will get more oil on everything before I do any more revolutions. (I did oil all of the journals and everything in between)

It is a basic tester, one way valve, and a little button on the side releases the pressure. It gets to 100psi and no more, but the needle doesn't even go back to the zero (or the pin) after releasing the air, which means it might not give any accurate readings at all. In fact, it might be broken.

But, I have to keep an open mind and explore further into making sure that everything is doing what it should.

That oil feed is going straight back, before anything else, and oil will be applied to everything I can get it to.

Then, I will do a leak-down test.

 

Well...think of that as a good thing and hopefully your getting more PSI's than the tester shows

I can do multiple tests ....unscrewing it every time and get different results each time (waste of £25!)

Im NOT impressed with this tester and wish I'd saved my old one now

The thing that bothers me is the way the tester thread goes into the plug holes........unevenly

 

We shall see. The compression tester is only a suspect and unfortunately, I haven't got another engine to test it on.

Mine is also uneven when going in... Cheap crap that cost me a lot more than it should.

I really want to get this bike back on the road ASAP. I keep seeing bikes go past me in my clapped out banger of a car, and it makes me shed a tear...

[SlowBusa]

the compression tester is only a suspect and unfortunately, I haven't got another engine to test it on.

Mine is also uneven when going in... Cheap crap that cost me a lot more than it should.

 

 

It cant be a coincidence that two random DIY mechanics have the same problem with the same piece of equipment

My last test resulted in 172 PSI

removed it and reinstalled then got 201 PSI on the same cylinder

[leener]

It cant be a coincidence that two random DIY mechanics have the same problem with the same piece of equipment

 

Absolutely. That's the straw that I'm clutching, right now.

If the engine is compressing at a normal rate, for my engine, then you'll hear me scream for joy, all the way from Bristol.

Fingers crossed for a good leak-down test.

If all is well, then I have a whole lot of cleaning to do on that frame. The engine was caked (and I mean CAKED) in dirt. The frame, suspension, swing arm, all of it is filthy.

[megawatt]

Reinforces my view that you're better off with a leakdown tester. You can hear where the leakage is coming from and get a good idea how bad the leakage is. Unfortunately you have to have a supply of compressed air. That said, my tester gave repetitive readings at 28psi.

[megawatt]

Reinforces my view that you're better off with a leakdown tester. You can hear where the leakage is coming from and get a good idea how bad the leakage is. Unfortunately you have to have a supply of compressed air. That said, my tester gave repetitive readings at 28psi.

[leener]

Reinforces my view that you're better off with a leakdown tester. You can hear where the leakage is coming from and get a good idea how bad the leakage is. Unfortunately you have to have a supply of compressed air. That said, my tester gave repetitive readings at 28psi.

 

It's been a while since I posted anything new in here, thanks to a cam belt snapping, and having to do a big job on a 96 Renault Laguna, just to get transport.

Today, I have a leak down tester and a good air compressor.

I have checked all three of the cylinders and the leak is low to none.

This confirms that my compression tester was absolute junk and that I need to gently put the engine back in the frame... After I put the sump oil feed back in. I must NOT forget that.

Meanwhile, I'm off to go view a replacement bike on Sunday, that I might buy, depending how well this goes.

It's a ZZR600E, looks identical to my old bike from ten years ago, same age, and the number plate is very similar.

My last one was sold on, but I found out that it was stolen from whoever had it, years later :

 

 

I'll be checking it over thoroughly, but may end up with two bikes if I finish this triumph.