Back (again!)

[IgorVigor]

Hello again

I might one day get to build a diesel motorbike :p

things just dont seem to work out at times though



I thought I'd just update on the situation though.

I've got an MZ ETZ251 which is a nice bike, but the engine is being a bit of a pain.
its just problem after problem really....

now the charging system isnt working properly.....

so the temptation to get a little diesel engine for it, is increasing exponentially with every problem!



now I'd only want a small single cylinder diesel, to keep the weight down.
a 10~15hp should be enough.

not sure what to do about the gearbox though....
I'd really like to stick to a 3/4/5/6 speed sequential gearbox, but if I HAVE to use a CVT, so be it.....

I dont want to modify the frame apart from perhaps engine mounts (I'd try and build a removable cage engine frame though), so stretching the frame isnt going to happen if I can help it.
and I'd like to retain the right hand side chain drive (preferably sticking to the sealed setup MZ use as well....)


So, any thoughts on the situation?


I know I'd love a big powerful diesel or turbo diesel motorbike, but this MZ wouldnt be it!
it would be a commuting bike
the MZ has a decent fuel tank (17L I think), so at 100mpg it would have a theoretical range of 375 miles





oh and one other MAJOR criteria......cheap....
it needs to be a super cheap conversion.....

[IgorVigor]

no one want to comment



might have to put my scooter based CVT idea into motion :p......

[Stuart]

The MZ is a good starting point Make it anything like the FlitzBitz and I'm sure you will have a winner on your hands. The 440 Lombardini engine with mechanical 2 stage injection is a good unit too

[IgorVigor]

yes, I had a look at them


just need a diesel engine now :p

I think a Petter AVA1 (~550cc) making 4.5hp @ 1,500rpm, isnt going to be the best engine
and its heavy :p



I'm just looking out for a cheap/free little diesel at the moment.....

[coachgeo]

cheap/Free and diesel engine are too items that rarely occur together

[IgorVigor]

cheap/Free and diesel engine are too items that rarely occur together

yes, but I can hope :p

at the moment, I have no money


I'm hoping/planning to build a diesel motorbike for early next year.........
I have a donor....I just need an engine and a gearbox.......

[rekrapdier]

Hey everybody,
can anyone send me a link or point me in the right direction to the two stage injection wonders of lombardini, I'm in the market for some 200+ mpgs.

I have a nice budget....

[OilyPhil]

Youve already got a 5 speed gearbox, just machine the MZ engine off it! That should also sort out final drive allignment if you use the MZ frame, you just need to make front downtubes and cradle and sort out primary drive. It might be possible to get the MZ clutch onto the diesel engine and get it to drive the gearbox.

Phil

[IgorVigor]

Sorry for not replying for a while


Since I posted things have been constantly taking turns for the worst



I considered cutting the MZ engine/gearbox so I'm left with just a gearbox....but there are a few problems....

MZ's are a chain primary drive from the engine to gearbox so it would need to be sealed.
the standard clutch is mounted onto the crank with the sprocket on the back of it....
and the gearboxes aren't very strong (and dont have undercuts on 3rd gear so easy to damage)

so I think its too weak to use.....



I'm going to measure the MZ engine/gearbox so I know roughly how much room I have to work with first......
I don't want to get a gearbox and then can't fit an engine in


I have 2 diesel engines I could use....but they aren't powerful....and they are heavy.....
one is a 1.5bhp at 1,500rpm Petter PAZ1 (350cc)
the other is my Petter AVA1 (550cc) which makes 4.5bhp at 1,500rpm

not a lot of revs





the thing is though, I believe I can get diesel engines from cars/vans quite cheap.....
I'd have a choice of the Peugeot XUD9 (1.9D or TD), the VW SDI/TDI (1.9), the Ford Endura D (1., or the Peugeot 1.5D...... (well there is a 5th option, but I think it would be too heavy.....the Ford 2.5Di transit engine...)

so I'm still considering getting a car diesel, and either running a setup like Mouse runs (no gearbox), or using a FWD car gearbox with the diff welded, and running a chain/sprocket from a single driveshaft.....

but I don't think the MZ frame would be strong enough, even with bracing to take the weight.......



so either route (MZ with small diesel or big bike with car engine) isn't simple

[Benzine]

the thing is though, I believe I can get diesel engines from cars/vans quite cheap.....
I'd have a choice of the Peugeot XUD9 (1.9D or TD)

Hi, I've got an XUD9TE engine on my workbench at the moment (ancillaries removed), let me know if you want any pics or measurements from it

[IgorVigor]

Thanks for the offer

If you could, an overall length including the crank pulley and flywheel would be useful.....

I could then look into what frames would suit....

[mark_in_manchester]

...or if you want to fix the MZ charging system I may be able to help...

[IgorVigor]

...or if you want to fix the MZ charging system I may be able to help...

Thanks for the offer.

I actually know whats wrong with the MZ after a fair bit of testing.....
first of all, I bought the bike with a few other issues, but it had been standing for 15 years...
the PO bought it, and rebuilt the engine, and then couldn't get it to run nicely....so sold it.....

I adjusted the carb properly (floats were way out), and it then ran and worked really nicely....
then the regulator decided to fail.....

the problems I've found (so far ) are as follows:

- the regulator needs replacing (ideally with an electronic one, instead of the electro-mechanical one)

- the entire wiring loom needs attention, and possibly repairing/replacing (the PO didn't do a very good job looking at some of the wiring )

- the carb needs replacing, as I've set it up 100% correctly, and its spotless internally, but for some reason its very hit or miss as to whether it allows the engine to receive fuel or not......(the fuel tap is clear, and the tank is clean, but I've heard of a few people with similar carb problems....)

- the clutch needs looking at as it drags badly, and rattles and won't adjust properly....
I suspect the clutch plates (which are most likely the original MZ ones from when the bike was new) have broken........also a commonly seen problem




I'd love to remove the entire ignition system and wiring loom, and fit a kart ignition (like they do on the racing MZ's)........
at least then its a VERY simple electrical system to ride the bike.....

I'd have to work out a way of running lights, but I thought LED bulbs all round (apart from the headlight), and then fit a 12v solar charger to the bike

[Benzine]

Thanks for the offer

If you could, an overall length including the crank pulley and flywheel would be useful.....

Hi, been to workshop today and had a quick measure. It's 51cm from front of crank pulley to rear of the starter ring. I have an auto flywheel, not a manual so I'd imagine you'd have to add another 3 or 4cm to that. (the manual flywheel is buried under a load of junk so can't get to it to measure)

[IgorVigor]

thanks

So really I need to allow 60cm for the engine (I'm better having extra space than running out )

I think I'll have a look around at bikes with blown engines.......
I reckon a sportsbike or muscle bike frame would be the best option......


the thought of owning a 1.9 turbo diesel motorbike tuned up to ~120bhp....... it would be brilliant!

[Benzine]

thanks

the thought of owning a 1.9 turbo diesel motorbike tuned up to ~120bhp....... it would be brilliant!

no probs! Yeah that would be nice with the bosch pump for easy tuning & veg oil compatibility. I read Practical performance car magazine and James Pickering has a 1.9td with 182hp and 280lb/ft of torque I'm currently putting one in a '67 volvo amazon.

[IgorVigor]

The bosch pump is much nicer than the lucas/cav

I probably wouldn't tune the engime much......
At most a T25 (possibly TD04) turbo, 11mm head in the pump and tweak fhe fuelling....
140bhp would be enough


A friend of mine has a tuned XUD9 that broke the 200hp mark....goes quite well

[Sphere]

Thanks for the offer

If you could, an overall length including the crank pulley and flywheel would be useful.....

Hi, been to workshop today and had a quick measure. It's 51cm from front of crank pulley to rear of the starter ring. I have an auto flywheel, not a manual so I'd imagine you'd have to add another 3 or 4cm to that. (the manual flywheel is buried under a load of junk so can't get to it to measure)

Would be a nice mate for the 3800+ rpm topic, a topic that will take car engines without stretching. But I guess those don't exist. Perhaps the 3-cylinder diesels will be small enough although I did find dimensions of a VW 3-cylinder and it wasn't smaller than Nanko's TUD5.

[mark_in_manchester]

[quote]the problems I've found (so far ) are as follows:

- the regulator needs replacing (ideally with an electronic one, instead of the electro-mechanical one)

- the entire wiring loom needs attention, and possibly repairing/replacing (the PO didn't do a very good job looking at some of the wiring )

- the carb needs replacing, as I've set it up 100% correctly, and its spotless internally, but for some reason its very hit or miss as to whether it allows the engine to receive fuel or not......(the fuel tap is clear, and the tank is clean, but I've heard of a few people with similar carb problems....)

- the clutch needs looking at as it drags badly, and rattles and won't adjust properly....
I suspect the clutch plates (which are most likely the original MZ ones from when the bike was new) have broken........also a commonly seen problem
[/quote]

Regulators turn up on ebay from time to time...I have one, but untested. Or Mz-B (was German, but now I think Hungarian) will sell you a permanent-magnet alternator / new stator / electronic reg-rec / elec ignition system (incl coil) for about £200, which is expensive in MZ terms but works very well - I have one on one of my bikes.

If your carb is clean and the float height is correct, then I reckon you've probably got an air leak between carb and cyclinder, if you're not getting fuel through - inlet stub (where carb is a push-in) or cyl base gasket being two frequent culprits.

Clutch rattle - never seen it. Some drag - need to adjust at the bottom by taking off tacho drive plate and spinning odd metal plate as far anti-clockwise as it will go. If you run out of 'slot' in the plate where the 3 screws go through, turn the plate upside-down, and more travel will be available. Handlebar adjuster is just for fine tuning.

Clutch plates usually last forever - I've had about 8 MZ250s of one kind or another...but be cautious about taking the clutch off the crank. A normal 3-legged puller will bow the clutch centre - MZ puller pulls from the middle - borrow one. And heat the clutch to 100 deg C before doing it up tight onto CLEAN crank taper (no keyway!) using tacho drive nut and some spacers, while it cools and shrinks on - if it spins on crank, you'll bugger clutch centre and maybe crank taper.

Aah, happy days...

[IgorVigor]

nder base gasket and head gasket show no signs of leaking....
The carb stub to cylinder gasket has been replaced and I even tried sealling the carb into the stub using rtv sealant
no difference.....
I think the carb is just old and worn out to be honest....
It wouldnt setup properly (when the bike was working)

As for the regulator I will be going for an electronic one which will be better than the electro-mechanical one...
The mz b ignition is nice but would cost more than the bike did
I'm tempted to get a kart ignition cheap and fit that to do away with the surprisingly complicated (for such a 'simple' bike) and battery reliant ignition system...
Thats the luxury of the MZ B ignition as well

As for the clutch plates I've seen a few articles about the last ddr built bikes clutch issues...
Basically the clutch plates become brittle if the bike hasnt been used....

Not much of an issue though....

I have adjusted the clutch correctly and checked everything over but nothing makes much differebce....hence why I have though about brittle clutch plates.....

I would luke to get it working again though.....its so much fun to ride

[XLerate]

When I rebuild small engine or bike carbs I like to soak the parts for awhile, then clean using a spray carb cleaner and wires. Some companies on the net sell 'jet cleaning wires' assortments, real handy. Guitar strings work too on many carbs.

After a soaking, spray an orifice with carb cleaner then gently work a wire in, maybe smaller first then larger ones as they fit. Keeping everything good and wet with carb cleaner gently massage the orifice with the wires to break up the shellac deposits, then blow out with more spray cleaner. Obviously you don't want to ream any holes or jets but they're pretty tough and you'd have to work to do that. When I'm all done I hit it one more time with carb cleaner then take it to the compressor and blow out all the jets & orifices with about 150 psi air.

The tiny little air breather holes at rim of carb intake are very important for smooth transitions from low speed to high speed. Also once you remove throttle piston or looking down bore you can see a couple of more air bleed holes in carb throat that need the wires. The jets most likely have emulsion tubes with holes in the sides of tubes, clean these holes completely. Also be sure a wire can pass all the way through from one end of jet and out the end of emulsion tube on the other end. There should be no blockage all the way through.

You may be amazed at the difference in how the engine runs once all the air, vacuum and fuel flow is corrected by cleaning all passages with wires! Best to wear rubber gloves and goggles to protect yourself and be sure to get plenty of fresh air while cleaning carb!

[coachgeo]

done a few small engines and few auto fuel systems and cleaned with wire like suggested in previous post buttttttt. from what I've read this is suposedly a big no no with diesel injection systems like injectors, IP's and the like. They seemed to say the orafice walls are too delicate and a scratch or unintential change of shape or size by cleaning with a wire can throw off the injection timing etc.

Just a .02 Ive read. Others milage may have shown much different. Would like to hear from others.

[XLerate]

done a few small engines and few auto fuel systems and cleaned with wire like suggested in previous post buttttttt. from what I've read this is suposedly a big no no with diesel injection systems like injectors, IP's and the like. They seemed to say the orafice walls are too delicate and a scratch or unintential change of shape or size by cleaning with a wire can throw off the injection timing etc.

Just a .02 Ive read. Others milage may have shown much different. Would like to hear from others.

ABSOLUTELY RIGHT!!!!

No disagreement there at all, this tech application is GASSER ONLY. That's why I specifically described carbs and the parts of a carb which don't exist in an injected engine. From what I saw in this thread he's wanting to have a beloved gasser running right and it ain't. This wire cleaning is the cure for the problem if the rest of the carb is in fact good. It's the delicate balance of vacuum signals, air flow and fuel flow that control the correct running of a carbed engine.

Fuel injectors even get damaged by the fuel itself eroding the orifices over time. Last thing a guy needs is to jump in there with wires and hog them out!

CoachGeo is entirely correct on that.

[XLerate]

Hey Stuart!

I wrote up a more complete article on gasser bike carburetor cleaning if you'd lke to post it here on site somewhere's. I don't think I ever posted it here before because it's obviously not injected diesel stuff. It could be some help on the guy's gasser bikes, let me know if you want it? Understood if it's not needed on a diesel bike website.

Thanks!

[IgorVigor]

I've been cleaning carbs for years and never had a problem

I think it just needs lots of new jets/tubes/etc inside it as they are probably the originals.....which makes them 22 years old..........

and lets face it......the east german carb isn't the pinnacle of brilliant build quality :p
shame really as its design is one of the best flowing carbs for its size!
its just the actual construction lets it down....

a nice Mikuni or Keihin flatslide carb would be much nicer and make it run smoother and more efficiently.....


money is the issue at the moment though




as for diesels and injection systems, I actually don't mind stripping them down......
they aren't as hard as most people think