Hayabusa to mz....

[Deedum9]

Hi all
Ride a hayabusa but wanted a project to do up and ride around for a bit.
Just bought (yesterday) a 1996 mz301, took it for a quick spin today, was running for about 2 miles, but then just coughed, spluttered, smoked a bit and died and now won't start.
I'm sure I will be a regular here...... Hello anyway

Steve

[Nobog]

Welcome to the forum.

Now its time for fun with 2-strokes!

I can't help (never had - or even seen - a MZ301) but just post on something specific if you need help. Many knowledgable people here.

Jim

[DAVID THOMPSON]

welcome
and where is your town and country

and if your gasoline has ethanol in it
that may be part of the problem
my rt125 runs much better on gas with the ethanol not added
or if it has sat for a while with out the past owner running it much
it may need a good tank and carb cleaning
also check the autolube pump and tank
that may need a good cleaning and check out
hope you did not seize a piston
see if it will kick over
if it will then clean carb and do check the 2 cycle oiling system to make sure it is correct
dave

[Deedum9]

Hi again, sorry I'm from Somerset in the uk.
It has clean fuel, checked the 2stroke oil, it was fine on tick over and ran fine , went to go for a spin, managed to get about a mile or so. Got upto speed into 3rd and then hesitation, wouldn't rev, clouds of smoke from the exhaust and then barely running. It eventually came to a halt and now won't start. Kicks over, has good fuel running, has a spark, now at a loss

[Adrian]

Hi,
Just read your post. Familiar territory for me I'm afraid! I assume you have checked the obvious? Evidence of fuel on the plug, healthy blue spark, reasonable compression?
Has the bike been in constant use or has it had a lay up?

One very common problem on bikes that have been laid up is hardening and failure of the main bearing seals. Two strokes rely heavily on an airtight combustion chamber. Once you have eliminated coil, condenser, plug and carb check the main seals.

Symptoms would be a heavily oiled plug as the engine will be sucking in gear box oil, which is another reason why the bike stopped. You would also notice a drop in gearbox oil.

If it is the seals they can be done with the engine in with but the clutch, primary drive, and alternator need removal all of which required special pullers.

I hope this helps and it is one of the simple things. I live in Devon so send me a message if you want to talk it through on the phone.

Good luck!

[Deedum9]

Hi Adrian
Purchased the bike and he had been using it regularly, its taxed and mot'd and I got it in Christchurch and bought it back to Yeovil in the works van.
I put a gallon of fresh fuel in from a can, checked the oil, tyres and went for a spin.
About a mile later it hesitated, smoked, lost revs and finally stopped and wouldn't start again. I wasn't going fast, just changed to 3rd gear and then that.
I have since discovered I have no spark from the HT lead, and right now the carb has decided to leak fuel aswell , but that's only the bottom gasket split.
So........what to check now, plug looks new, but I have no idea how to check the coil etc , if indeed it is that ?

[therealche]

Ok first of all just try a new plug. In many years of MZing I have found that putting a new plug solves 99% of all MZ problems, poor/non starting, failing indicators, poor lights , flat tyres ( well OK probably not flat tyres!)

[Deedum9]

funny thing is , I was trying to look at plug and lead, coil etc.
I took the plug out to earth somewhere on the body, as soon as I flick the ignition on, there's a brief spark, but no spark when cranking ?

[arry_b]

Have you got points or the "red box" electronic ignition under the R/H engine cover? The red box gets unreliable once it's 15 or so years old, a common problem. I've bought three such non-running bikes that I converted to points ignition (simple enough - points, a points cam and backplate from an older bike).

Once converted, they just kept on going.

[Deedum9]

to be honest, I haven't looked yet and have no idea ? plug lead and cap ordered, which was cheap enough, i'll try them first and keep you posted - thank you

[Adrian]

Hi, well its sort of good news if its not crank seals but it does sound as though its an ignition issue.

So its down to going through the electrics methodically. If it tracks back to the electronic timing then it is good advice to go back to mechanical points.

You can get a new Haynes manual on flea bay for under £15. That would help you with diagnosis

All the best,
Adrian

[Deedum9]

I've downloaded a Haynes manual, awaiting on plug and lead first and then to track down the points

[Adrian]

Just one other thought. The choke cable disappears into the carb and leads to a tiny cylinder with a rubber disc at the end of it. These discs can distort/wear/breakup. The disc effectively closes the choke off. Even if the adjustment of the cable is too tight it can have the same effect. Should have eight of an inch of slack. Just worth a quick look.
Adrian

[Deedum9]

posted on my other post Adrian