Post Valve Check/Shim, Running Lean

[Overlord Neil]

Hi Dandy,

Checked pressures again with the throttle wide open, now not getting any readings at all. If I put my finger over the extension tube screwed into the spark plug hole, there is positive pressure but I suspect its too low to register on the pressure gauge. The pressure gauge has a check valve to 'log' the pressure on the gauge, I even used a second gauge in case there was a problem with the kit.

I'm guessing to confirm the valves are closing I'd need to take the head off? Reasons the valves wouldn't close would be dirt/debris on valve and/or valve seat, incorrect clearances and valve damage? The clearances are all set within tolerance so the valve shouldn't be able to hold its self open without pushing off the cam lobe?

[BigAl-TC]

Hi,
Just a thought, but is it possible to have the crank 360 degrees out? Just sounds like valves open at wrong timing.

[dandywarhol]

Or the valves aren't seated if bent. You could still get a clearance that way.
If you could fit the compression tester extension to a low pressure air supply and set the engine at TDC firing stroke, you should be able to hear compressed air leaking out the carbs or exhaust if the valves aren't seating fully.

[Overlord Neil]

Hi,
Just a thought, but is it possible to have the crank 360 degrees out? Just sounds like valves open at wrong timing.

I'm starting to wonder myself... I've got bit of garage time this afternoon so i'll start with the basics. The bike was running albeit badly before it was stripped so hopefully its a re-assembly issue.

Has anyone bent valves before can your hear them go, I'be not heard any knocking noise at all.

[cobbadiggabuddyblooo]

First look at the action of the valves at TDC on overlap. Then look at which way the inlet cam had unloaded.
If my memory is correct this will make the inlet valves close a little later. I think you'll find there is quite a lot of clearance and even with the later closing inlet valves, my hunch would be the valves are not bent but possibly the damage was done previously. When the valve or valves are bent, it's usually instantaneous from running ok to up the shit bonza.

[Overlord Neil]

Turns out the knobber (that would be me then) that put the top end back together... got the inlet cam shaft 180 degrees out. The timing lines were correct on the cam sprockets so it 'looked' right but very much not.

Cylinder pressures have gone up but still not enough, though I wonder if that is more general wear and tear on the pistons and rings, the bike has 44,000 miles on the clock and does use oil. Cylinder 1 showed 125 psi, cylinder 2 90 psi with the throttle wide open. I hadn't pressure tested the bike before stripping it down so I can't say if its down on what it was.

Got enough back together and even trialled a test fire and low and behold, she coughed and wheezed and nearly ran under here own steam, though i suspect me feeding fuel into the carbs under atmospheric pressure rather than via the pump might have stopped her from roaring.

[cobbadiggabuddyblooo]

All a part of the learning curve Neil, I got sidetracked and made a couple of foolish mistakes when putting my motor together and sat back and wondered why things didn't seem right... Lol
You'll be a pro at this when it all comes together again mate...

[Overlord Neil]

Update time, I've managed to score two whole days garage time

I eventually got the original cylinder head off the bike, which have been a whole lot easier if i'd a; read the manual (I didn't see the two long M6's hidden in the cam chain void) and b; not had to cut the exhaust studs to get the bloody exhaust off, more on this later. Established that I had indeed bent the valves on the original head, there were witness marks on the cylinder and the outer two inlet valves of cylinder #2. As a sanity check I flipped the new head upside down and filled the combustion chambers with petrol (all i had available) to check for leaks; all good. Then I reassembled the engine with the new cylinder head on the old head gasket to check it was actually the head that was the root cause of the low compression reading, loosely screwed on with an old gasket getting 75psi on both chambers which for now I'm happy with.

Gave the new head a bloody good clean and left oven cleaner in the exhaust ports over night, that stuff really works! Stripped the head down, took all the valves out to clean the stems, despite the ports coming up clean the exhaust valves were still thick with carbon crust. Quick spin in the pillar drill with a sharp edge then a bit of synthetic wire wool (note don't try this with actually wire wool, it just wraps itself around them stem and yanks out of your hands. Synthetic wire wool is like an industrial scothbrite cloth with teeth.) All the valves looking shiney and new I decided to lap them into the valves just to be triple sure they were sealing properly. Nice shiney band around each valve and seat now, all good.

With the head stripped I had an over whelming urge to do a little porting work. Rather than go nuts I decided to keep it simple, theres lots of information out there on porting and how 'easy' it is, it also incredibly easy to royal roger your bikes characteristics so I just went for a very mild option to blend the step under the valve seat, some where worse than others and none of them were horrendous. I haven't changed the port size or cross sectional area, just improved the flow at the valve. Next I had a go at the inlet manifold stubs, and roughed these up instead of the smooth bore as standard. For all of this I used a dremel-esque tool I bough from Aldi a while back, absolutely no grunt at all, but that was a good thing, I've got a compressed air die grinder and carbide bit set but that could have led to tears.

Another good scrub, degrease and clean out to get rid of the cutting debris and grinding paste. Head now re-assembled and valve clearance checked and set (soo much easier on a bench!) one thing that did strike me as odd, putting the cam shaft retainers back in and torquing up, exhaust all good, inlet was pinching to the point were it was much harder to turn than the exhaust cam. Spent a good while fault finding and tracked it down to one of the four bolts that holds the cylinder 1 inlet cam shaft retainer in place; if i torqued that one bolt to 6nm the cam shaft span freely, take it to 10 and it was really hard to turn the cam shaft. Couldn't figure out why but happy to leave that one bolt at 6nm unless anyone has a stroke of genius or a really good reason not to.

As i mentioned earlier, getting the exhaust off was a pain in the ass, the studs had seized solid in those lovely thick aluminium retaining clamps, I don't know when the exhaust was last off but I've had the bike 2 years and ridden it in all weathers and never looked at the exhaust, so its had plenty of time to fizz. I got one of the four bolts loose but the other three weren't moving, even after I had cut them off I figured a good twating with a club hammer would shift them but no, then tried to drill out the stud, broke the drill about 25mm deep... gave up. Had a look on fleabay, theres a guy selling a trx standard exhaust but they obviously had the same problem and have cut the retaining clamps off... so you can't actually mount the exhaust, unless you make your own set of clamps. Anyway, I had a quick check here first before hitting the buy it now button, and bought an old Micron tdm850 2 into 1 stainless pipe, interestingly its a 2.5in pipe so might make a bit more go too.

Thats a far as I've got for now, waiting for bits then hopefully the final assembly.

[Mincehead]

Neil, use SPLIT 2 piece clamps like these:

http://www.ebay.co.uk/itm/Kawasaki-ZX10 ... Sw9r1WCRC3

Those FIT by the way, it`s ALL been discussed in detail over the years.

[Overlord Neil]

Good tip Mince cheers, good to have a back up as I've got Remus Carbon end cans which suit the bike nicely.

I was going to put it to the collective wisdom (when the new pipes arrive) to see if anyone new of a 2.5in/63mm slip on to 3 bolt adaptor? I've got a Fuel twin port end can for a fireblade with a 3in ID 3 bolt flange which would go nicely I think.

[dandywarhol]

I would be reluctant to leave one cam cap at 6nm - there must be dirt/slight metal damage/cap damage to cause that. With the cam out, check there's no lip or edge where the cam runs, a scraper tool would clean up any imperfection. You really don't want that bold loosening and causing mayhem!

Re. the Micron - through experience, I've had a helluva time setting up a Micron 2:1 with CV carbs - couldn't sort out a big hole in the midrange and reverted back to 2:1:2

[Overlord Neil]

Was the problem resolved with flatsides? If I get the bike back up and running I'm thinking of treating her to a set of Mikuni flatsides... controversial but pennies rule out, Kedo are selling the TDMR40's for the TRX at about 1000 Euros, trying to find somewhere the sells the FCR's is one thing, the cost is pretty eye watering.

I'm going to threadlock that one bolt, I spent a good hour or so studying what the problem was the other three bolts on that retainer are good at 10nm its just that one. Does anyone know if those location spigots also act on their length went bolted down or do they only provide a concentric location? The only thing I did find was the bottom of the dowel hole wasn't pretty, like the dowel had been located with a hammer at some point, which could explain why the bracket pinches them cam when tightened. Straws and wild clutching come to mind.

[dandywarhol]

Never had the operchancity to get flatslides - problem was sorted by reverting back to 2:2 and Factory Pro carb bitties.

Others will know better but I'm of the opinion that flatslides and small bore 2:1 aren't ideal. any worthwhile 2:1 has large bore and large volume silencer

[Tarwetijger]

Was the problem resolved with flatsides? If I get the bike back up and running I'm thinking of treating her to a set of Mikuni flatsides... controversial but pennies rule out, Kedo are selling the TDMR40's for the TRX at about 1000 Euros, trying to find somewhere the sells the FCR's is one thing, the cost is pretty eye watering.

I have TDMR's for a couple of years, they are great! The 'new' bike came with FCR's, so I am in the position to make a comparison. I fitted the TDMR's on the trackbike, as the FCR's are said to be 'slightly rich', for 'better ride ability' I think it is an awkward thing to do but well, I will check the main jets first. The sparkplugs from the particular engine looked fine though; brown - just a tad darker then what you would want.

For unknown reasons (to me) most people on this forum are very FCR-minded.

[Overlord Neil]

Thanks for the feedback! Good to know, there are a few members with a positive experience of the TDMR.