Z900 engine problems

[debben1]

Leak down test takes about 30 minutes £20 should cover it , Dyno run would be another £40.00,

[Phil50]

hi Steve

I have found a local place in NW London who will do the Dyno for £20 and the leak test fo about the same.

So he says. However this place is a god shop as I took the bike there when a bought it a few years ago and the owner tried to fix it, never charged me for about 4-6 hours work ( I took him some booze)

He did write put a full report that I presented to the seller vie my solicitor prior to a Count court case. He folded like a cheap suit and paid all the money it cost me to fix the bike and make it roadworthy.

Very amusing time. A dealer ( West London con man) actually though he could sell a bike that was not roadworthy simply because he had a MOT he got "done" for the bike.

I fixed a minot fault on Friday in that the handlebar switches that are sold now are incorrect in that the headlight small bulb is on all the time.


It should only come on when you flick the switch to first postion. Actually you simply remove the brown wire and cut in to the Red from the 4 way and presto its the switched 12v feed and all is well.

I removed the carbs,, put a new pipe in from the oil breather and fed it to a small bottle hiding now in th etool box compartment.

Why did I not think of this trcik!!!!!!!!

Much neater.

Anyway after full cleaning and re assembly a 2 second squirt with easy start and it fired up perfectly after 9 months off. Not bad!!!!

Hope is here again. The rebuilder has not won yet.

I shall be taking it next week to get the MOT done and then to a professional garage for this leak down and dyno test.

If they can prove the re build is the problem, I shall be taking the steps again to get matters put right. I have after all paid a lot of money for a job that may not have been done correctly.

I shall report after the test is done.

thanks all

Phil

[Phil50]

Thanks Steve

I took the bike to your recommended chap. He found the fault, head gasket leakage between cylinders 3 and 4.

So this has been the problem from day 1 ever since the "expert" re-built the engine.

All that crap he gave about crankcase top and bottom not original or mating up correctly.

All the time it was his lack of knowledge and incompetance when a problem arrived that he did not wish to deal with.

The memebrs must be careful who thyel et near their bikes thats for sure.

thanks again Steve

regards
Phil

[Phil50]

The bike failed the leak down tests and it was found the member who re bulit it had not installed the head gasket correctly.

IT was leaking from pot 3 to 4!!!!!

So I also had to have the head and barrels milledas they also were out of spec.

Anyway a new gasket set was installed it ws all put together with the correct Torque settings and with a new Vance and hines exhaust system.

Blow me if it still leaks oil all into the air box. The bike has been totally bollockesed up by the re-builder.

I have to look at the options now its gone too far to let it go.

My bike has been ruined forever and it seems it is no longer an economic option to keep throwing money at a problem I did not cause.

regards

Phil

[garyd]

Bout time to name an shame to make sure no one here falls prey to the so called expert.

"However I will not name him for now until I have checked all the ramifications of doing so. "

[Garn 1]

I read with interest this posting.... "Oil in air-box".
So we know that a problem has been solve regarding head gasket and mating surfaces.

I guess we have to now to turn to the failing of leak-down test...
Which must mean clearance between bore and piston, according to a previous posting. Are we sure of this statement? That too much bore clearance will cause crank-case compression. The rings must be working hard to allow that compression to be 145PSI.

When you say it failed leak-down.... what are the relevant readings re-failure?

Good luck with the job, just take it slowly... Do what a mate did, when his bike fell off the lift, after he had just completed everything regarding his overhaul. He just checked for spillage and then left it for another day!

RegardZ

[zed1015]

Leakdown test will also show up valves not seating etc and should pinpoint the problem area if the person performing it knows what they are doing.

[z1bman]

i cannot imagine the problem with the head gasket not being fitted correctly or the cylinder head surface not being flat would cause oil to get into the air box? did you get the bore + piston rings measured when you found out that the gasket was fitted incorrectly? if you explained your problems to who ever has done the investigating work + they didn't check this they are not any more qualified than the guy who fucked it up originally . you would have probably been better of going with debben engineering + saved yourself some money. we all have mates who say they are mechanics / fitters but have probably only done an apprenticeship if even that. your original engine builder was probably a fitter? there is a big difference between mechanic/fitter + a mechanic/ engineer

[Phil50]

The head gasket was leaking from pot 3 to pot 4 hence the excessive pressure building up in the crankcase.

The purpose of the crankcase breather is to allow gasses that build up to go somewhere

The head and block were also out of sync and had to be ground. The chap who did this assured me he had checked the pistons and ring end gap.

The person who put the engine back together is supposed to be one of the most knowledgable people around. He handed the bike back to me with two faults, neither of which he took full responsibility for.

I decided it was pointless to keep paying for tests so have purchased a leakdown test kit and a friend has a compressor who actually does know a lot about the Z900/1000 bikes he had both and did all his own work.

The latest episode from today is I have fixed the fuel tap which was not delivering sufficient fuel flow to carb 3 and 4. The timing has been done and strobed up to perfection. I have also cleaned out the drain hole into the crankcase inside the bell housing which was clogged a bit.

The carbs I have balanced to 9.00 inc/hg per the manual. The bike fired up perfectly and settled down to a steady tone and apart from a slight spit back when revved up ( this may mean 120 jets to go with the new Vance Hines pipe) sounded great.

Tomorrow I shall ride it and test to see if there is any oil blow back as before. If so I shall of course have to leak down test again myself if it passes ok if not it will be a fulll rebuild by the first garage who did the job 4 years ago perfectly. I hope though it may now be fixed.

Steve at Debbins has been most helpful but the distance from him to me precludes the bike going to him

regards all
Phil

[steve bowdler]

Steve at Debbins has been most helpful but the distance from him to me precludes the bike going to him

Is it too far ? surly only about hour and a half away ?? .

Then it will be sorted