MZ/MuZ Riders

can the cylinder head be easily removed with the engine still in frame ? thinking on doing a decoke / service to the top end this winter..

would it be worth putting in a new set of rings while i am at it... engine has done 30,000 miles but running strong...?

thanks AL.

If it isn't burning a lot of oil or doesn't have visible blue smoke coming out the rear end you should have plenty of life in the factory rings. These motors are built to run forever as long as you change the oil and air filters on a regular basis and don't rev the piss out of them for long periods of time. Check the valve clearance and you should be good to go. Have you done any mods to the intake/exhaust or rejetted the bike? You'd be surprised how much pep is in the stock set up after a few tweaks if you are used to a bone stock bike.

If it ain't broke don't fix it

bike has a bsm future exhaust system thats it... I did the valve clearances a while ago... bike runs and doesnt use any oil... i leave it as it is then... i just wondered if it was easy to remove the head without taking the engine out ?

handsomejackuk wrote:bike has a bsm future exhaust system thats it... I did the valve clearances a while ago... bike runs and doesnt use any oil... i leave it as it is then... i just wondered if it was easy to remove the head without taking the engine out ?

Full exhaust or just mid pipe and/or silencer? If the stock headers are in place, and they are anything like the stock Skorpion headers, you'll need to grind the welds on the inside for the aftermarket exhaust to do it's job. They are very thick on a lot of factory exhausts. You can open them up at least 2-4mm usually, which is a lot if you run the numbers. On the intake side, it's usually the snorkle that is the most restrictive element. Pull that thing out, get a good air filter, grind those welds, then rejet the bike and you'll be pulling wheelies with much more ease than before. There was also a kit developed by, I think it was a company called Tunebike, that made the engine respond much more quickly and flow more volume of air. A company called off-the-road in Europe used to sell them but I can't find them anymore. If you do find one, don't use the drill bits in the kit to modify your main jets, they are much too large. Just do the mods on the CV slide and diaphragm and start leaning the bike out. The stock main jets are stupid rich, and the pilot jet too lean on the Skorpion. Don't know if they treated the Baghira carbs any different but I doubt it. That's all cheap horsepower. If you really want to clean up the intake, buy an intake spacer for a Raptor 660 and use it as a guide to port match your carb boots to the head. If the added thickness makes it too hard to get the carbs back in, you can always pull it back out. But the boots will be matched now and flow much better. Then again, it would be hard to keep those aluminum shavings out of the engine if doing this while assembled.

whoah thanks for this... i only have the silencer and end pipework, not the front pipes from bsm... not sure on the intake snorkel bit you refer too...? There is an air box, and two rubbers that go from the airbox to the carb intakes..

that raptor idea is a nice thought, and the welds you refer too i have to take the front pipes off and have a look and get in there with my dremel...

Al.

A Dremel will do it but you'll be there a while and/or go through a ton of sanding drums. Last time I did header welds, I just went to Harbor Freight tools and bought an electric die grinder and some stones for cheap. Saved myself a lot of time and I have another tool.

The snorkel is usually on top of the air box, under the seat, and usually made from rubber like the boots between the air box and carbs. Just removing it usually provides a much more freely flowing pathway to the carbs if your filter is up to the task. The XR650 supermoto guys are doing this(refer to pic) to get more flow into the box. There's a kit that provides templates and screen material but pulling the snorkel achieves the same goal if you have one to remove.

https://www.off-the-road.de/en/home/ for the slide mod

I fitted a pair of Raptor 33mm carbs to my 660 - probably no extra power to speak of but much more responsive. 43 hp at the wheel

dandywarhol wrote:https://www.off-the-road.de/en/home/ for the slide mod

I fitted a pair of Raptor 33mm carbs to my 660 - probably no extra power to speak of but much more responsive. 43 hp at the wheel

Those are pretty good numbers at the wheel if all stock internals. That's about where my bike was before doing a lot of work on the engine, and I thought it was about as much as I could squeeze out of it. Stock carbs with the off-the-road kit(don't see it on their site anymore) on my modified engine put out around 60hp and that was "turbo rich" according to the dyno operator. Now that I have a dual Mikuni setup with a 34mm on the left and a 38mm on the right, I'm pretty sure it will push the peak hp number well above the 65 mark. I just hope it's not over 70 because that's a bit much for the clutch basket and rod according to what I've read. Some day I'll get all the loose ends tie up, get the bike back together with the programmable ignition working right, and make the final trip to the dyno for a long and thorough tuning session.

I've still got a CP 727 kit with Carillo rod, Hotcams3, Kibblewhite guides & springs, 2 x 33 Keihins, Projection Components downpipes, Ignitech CDI and a lower 5th gear engine to build - other projects getting in the way......................

dandywarhol wrote:I've still got a CP 727 kit with Carillo rod, Hotcams3, Kibblewhite guides & springs, 2 x 33 Keihins, Projection Components downpipes, Ignitech CDI and a lower 5th gear engine to build - other projects getting in the way......................

Probably want to look at a billet clutch basket if all that stuff works well together. You gonna do a valve job too? My guy ended up installing +1mm stainless valves on my head. Can't remember why but he only charged me for the extra cost of the valves over the standard labor/parts cost.

edfmaniac wrote:

dandywarhol wrote:I've still got a CP 727 kit with Carillo rod, Hotcams3, Kibblewhite guides & springs, 2 x 33 Keihins, Projection Components downpipes, Ignitech CDI and a lower 5th gear engine to build - other projects getting in the way......................

Probably want to look at a billet clutch basket if all that stuff works well together. You gonna do a valve job too? My guy ended up installing +1mm stainless valves on my head. Can't remember why but he only charged me for the extra cost of the valves over the standard labor/parts cost.

Most of the work had been done when I bought the project. It has std sized Kibblewhite black diamond valves with deep recesses in the heads. The CP piston is 12:1 comp. ratio but the valves recesses bring that down to 10.6:1. I'll probably skim the head to get back to nearer 11.5:1.

Who makes billet clutches? I missed out on a full race gearbox to Sanddune on here - such a pity I procrastinated and mentioned it to him

Hinson makes a good one if I remember. I know the Raptor 660 clutch fits the MZ but not entirely sure about the basket. Might do some research first but $250 would buy some good insurance.

Thanks for that