What's a boy to do? Advice needed!

[manbearpig]

What should I do?

I bought a very nice looking Z400 D3 off ebay not too long ago for £920 which I was chuffed with because it is a lovely looking example. It has even been used as library sample pictures as such a fine example - anyway - looks can be deceiving. It transpired that when hot, the engine would smoke and burn off a lot of oil. The tick over was also very high with no more adjustment, and the clocks weren't working and it had an oil leak from the crank casing.

A few phone calls, an empty wallet and a few hours tinkering later, I took the carbs apart and cleaned the jets, replaced the float chamber O-rings, the main jet O-rings, changed the crank case gasket and gave it a genuine new speedo drive, and new speedo and tacho cables.

Still smoking like hell. In fact, it burned off an entire engine worth of oil in the journey from home to work, then ran itself dry on the way back home and mildly pickled the engine. I then bought a replacement engine off ebay and had it delivered courtesy of bignut. With a bit of tinkering (had to re-tap the exhaust clamps) I got the engine in the bike and running sweet.

The problem is this one smokes as well and I just don't have the time or money to spend on the old lump and giving it a complete strip down and rebuild.

My question is this. Should I just sell it as is with current mot, a spare engine, tax and a smoky running problem, or should I strip it down and enter the world of pain. How much do you reckon it's worth as it is? and how much fixed? It's a rare and desirable bike nowadays and I am truly, truly gutted to see it go, but enough is enough. What would you do?

[retrowagen1234]

strip and fix.... you'd feel better about it in the long run and if you strip it first, find the fault and lay money into that rather than guess it mite be XXXXX part and lay money on it,

[93fxdl]

if the only problem with the lump is burning oil then it can only be coming up past the rings or down past the valves. so my route of attack would be track down any breathers and make sure they are clear so no chance of crankcase pressure forcing oil past the rings next would be a compression test to see if the rings are gone if the pressures are ok then pull the head and change the stem seals and check the guides and while the head is off it is probably as well to pull the barrels and check the rings incase any are broken or sticking but if pressures are down pull the head and barrels to check the pistons/rings but it would be as well to check the valves whilst it is apart
but this is all assuming you are using the correct grade of oil as a lot of modern oils are pretty thin and these older engines usually need 10/40 but wiyh a bit of wear it might be an idea to try 20/50
but before pulling down check price/availability of parts
ttfn glenn

[manbearpig]

Nice one man. Sound advice. The thing that scares me is it's an overhead cam. I'll strip the viva down any day of the week but cam chain allignment scares me - I don't think it would be a quick job!
the other thing is price of parts. So far just the rubber gaskets for the carbs were £40, speedo drive was £70, cables about £25 each..... Big end bearings, full gasket set, valve guides, rings and getting the bores honed (even if I brought a tool and did it myself) or possibly a re-bore and larger pistons and the cost is out of my range, so it would have to be a slow burner and get the parts when I can. I'll have to check when the mot runs out, but if it's got 7 months or so still on it, is it worth me cutting my losses and getting rid?

How can I check the compression in a cheap way? I checked the breather hose linking from the top of the head to the airbox and removed the breather casing from the top of the engine and both were clean. Is there another breather anywhere? Inside the barrels breathing between the head to the crank case?

[93fxdl]

probably the cheapest and quickest way of getting a compression check would be to ring the local garages to find one with a tester and scoot round and get them to test it or if you want to go down the diy route take an old plug, rip its guts out and fix a tyre valve down it then use a tyre pressure gauge to read the pressure as you spin it over
don't be scared just because its ohc J bike engines are (usually) almost self explanatory when pulling them down plus you have your stuffed engine to practice on
start by turning it to tdc then take out the cam chain tesioner then the cam then the head comes off
something to help is take pictures at every stage of pulling it apart so you have a record of where it all goes
ttfn glen
a possibility is the rings are gummed up so a bit of redex or similar may help
ttfn glenn

[retrowagen1234]

is it important that its done asap? i mean could it be a slow going project while you find cheap parts? they are out there, as long as you look about theres alot of small companys usually down lil back roads with shelfs full of obselete parts for motorbikes..... like my c200 i found a place a few miles away with a NOS seat and tank!! both for 50quid!!!

[Kyle67]

How much have you run this new engine? It could be just the oil left in the exhaust burning off which would take some considerable time. Take it for a good blast down a duel carriageway, using the redline often.
If that isn't the problem, it may be worth getting the barrels rebored and a new set of rings.
Don't be put off by the OHC, just tie something to the chain before removal off the sprocket to stop it dropping into the crankcase. Z engines are very simple to rebuild.

[manbearpig]

Wicked, thanks guys. I'm going to get a run down of the costs of parts tomorrow and see what I'm dealing with. Really sound advice guys. Thanks again.