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Discussion Starter · #1 ·
First post, glad I found this great website.
Recently bought '99 Mach Z. Previous owner did not have much info to share with me. Got a good deal, figured if something major needs fixed that I couldn't tackle myself I can take to a mechanic.
Already fixed reverse. The chain slider plate was never installed. Other little things fixed like new break micro switch.
We haven't had snow yet to give it a good run but I know I'm fouling the center plug.
My first question - to test plug wires can I switch them around to any plug combination to see if fouled plug follows?
After that I gotta get into the oil pump return spring, choke staying open, clean carbs, clean rave etc... (have read a lot of posts on here for tips).
FYI, My plugs are gapped to spec .018".
Exhaust smoke pretty heavy, plugs look oily wet but again, I haven't had a WOT test to compare.

You guys are great - Any help will be much appreciated.
Thanks.
 

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Hi Bob,

First off, welcome to this insanity!

Feel free to swap around those wires as needed. Also have seen some guys saying that they've trimmed 1/4" off the insulation and re-crimped the terminals and had good luck with that. I've also had good luck running the BR9EYA plugs and never had one foul yet; change them annually.

Start with a compression test. You want them EVEN. I have a 2000 MZ that was about 5psi lower on the center cylinder and discounted that as 'no big deal' and bought it anyhow. It turned out that the 5psi lower was actually a piston was partially melted from somebody driving with dirty carbs just long enough to begin to cause lean damage. I mention this, because this sled started right up and ran a little bit smoky, but overall didn't sound like it had internal issues. Of course the previous owner had no clue about this.

If you haven't read about the tendency for water pump leaks on these things, I'll summarize by saying it should be an item of high interest. When they leak, the engine sucks that water into the mag side cylinder. I'd pull the plugs and look down the holes just to make sure the mag cylinder doesn't look strangely cleaner than the other 2 from getting washed with coolant. I know several guys also add gear lube to the water pump bearing cavity during their annual check up's also to ensure the bearings are lubed, although the oil is naturally scavenged in there when the engine is running. Its probably not a terrible idea to give a shot of oil in there while you have the pipes off.

If you haven't looked at the underside of your carb boots for de-lamination and cracks, do so!!! It also gives you a chance to peek at the condition of those 20y/o oil lines.

Clean the carbs too. Before you 'test' it out! Trust me, they also run pretty good with a massive air intake leak that's waiting to burn it down.

It seems crazy to buy a sled and pull the motor right away, but it is probably the best advice I could give to anyone new to rotax triples that isn't familiar with the details of the machine.

One, you gain familiarity with the machine, and it also gives you a chance to spot problems before they become a much more expensive repair that ruins your day on the trails.

Two, you have a great support group here to help with the trials and tribulations along the way. Many CK3 parts are long discontinued and having help with sourcing and lower cost options here comes in handy as well.

Three, its tough to find a repair shop that has the know-how and can support these old triples. Being able to diagnose things yourself will come in handy.

I'll say it; every one of these is a ticking time bomb without the proper maintenance. You're money ahead to dig in and get acquainted.
 

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If somebody has a way that Bob could download the 1999/2000 PDF service manual, could you help him out?
 

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Discussion Starter · #4 ·
Update....

Turned my oil pump down a bit. At idle the hash marks lined up perfectly. I read somewhere to turn it down to where the marks align when throttle cable slack is removed.

I turned it down to about 11 o'clock (i did not get a cable length measurement to share). Now when I slightly press the throttle and remove cable slack the hash marks aligned perfectly at 12 o'clock before opening up the Throttle Valves.

A return helper spring was already on the oil pump lever (not sure it that's stock). It was a bit weak so I shortened it up a bit.

Also, adjusted choke cable just a tiny bit to ensure choke was closing all the way, spring looked good did not adjust it.

Looked down cylinders, all 3 tops of piston heads have carbon buildup, not one head clean (possible coolant leak).

Next I'll take carbs off and tackle cleaning them.

Any easy way to check power going to my plugs? Consistent power...... I keep reading about lack of power from the stator and points etc....

All I have is multimeter, willing to buy tools and learn though.

Don't want to jinx it but did not foul a plug when running in garage. Appeared to smoke a little less at idle, still lots of smoke but less.

Plugs where not oil wet like before. Were carbon black, maybe slightly gold-tan colour.

Thoughts anyone ????

Thanks
 

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I would drain the oil tank and refill it with Bombardier oil unless you know for sure what oil the previous owner was using. Drain the gas tank and put new fresh gas in the tank. Preferably Non-Ethenol.

Shoot us a picture of the 'return spring' you shortened. Something sounds fishy here.

Lynn
 

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Discussion Starter · #6 ·
Just a generic picture I sketched on to help explain this added spring return.

If I unhook this spring the arm does not fully return back to the hash mark let alone past it to my new idle setting (11 o'clock).

I shortened this spring to ensure arm is returning to new alignment setting.

I will drain oil and gas tanks asap for I do not know how old or what is in there.

Thanks for all the advice.

Oil Pump Spring.JPG
 

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Hoping someone with a '99 Mach Z chimes in here. Unless I'm totally wrong the pump arm should have a spring on it which is attached to the pump body. This spring not only acts as a return spring but will force the pump arm around to full oil flow if the cable from the throttle lever should break.

Lynn
 
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Discussion Starter · #8 ·
Now I'll have to test this out, you have me thinking.

There is a spring in behind the arm nut (highlighted seen below) but I think that is to return to "close".

This is the spring that I thought was probably 20 year old weak and needed the added "helper" spring attached by previous owner.

Maybe the return spring is internal and this spring indicated below is the fail safe spring.

I'll take the muffs off again and see if pump rotates wide open if cable is disengaged (simulating broken).
 

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They have a spring behind the arm, and does work as you mentioned. If it has a flat spot in the rotation, which many get when the miles start to climb, lots of folks add another spring for increased return force.

Here is a good read, from a very knowledgable member who no longer comes on here unfortunately:

https://www.dootalk.com/forums/topic/707938-oil-injection-pump/page-2
 

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Discussion Starter · #10 ·
Good read but a little hard to follow.

In simple terms what happens if the cable breaks?

Is there a fail safe in place to flood the engine with oil or does it stop pumping and become a ticking time bomb?

Thanks
 

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I do not see any information on that in the service manuals. Tells you how to test output and check valves, and how to adjust and pressure test the system.

Sounds like a smart fail safe, best way to find out is to put a drill on the pump shaft, no cable installed, and see what happens. Put the lever at the idle scribes, actuate the drill, see what happens. Then go to full throttle as if it had a cable, repeat. Then just let the arm go to it's stop point as if no cable and do it one last time.
 

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Discussion Starter · #13 ·
Thanks for the manual.....
Not a good night testing in the driveway. Fouled right side, replaced plug and then fouled left side.
Looks like it's going to be a bigger issue than turning down the oil pump a bit...
Guess next will be cleaning carbs?
 

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Ive always been told that if the cable brakes, the pump goes to wide open and dumps oil in. Ive never confirmed this though.

Yes, miss having thumbdoctor around. He knew his stuff. As he maxmachz pointed out, the pumps will wear and it is common to add a spring as you have or previous owner did to help get the oil pump to fully close. Personally I wouldnt go leaning out the oil pump any more. I dont think thats your issue.

Its popular to lower the pilot jet in the Mach Z's from 50 to 45. This is done to help with the issue of fouling the plugs when idling. When you take the carbs apart, make sure the air screw is set at the proper position also. If you drop to 45 pilots, if it gets really cold the idle might be a little high and you might have to up the pilots back up to 50. Not familiar with how far north you are and how cold it can get.

I am no jetting expert by any means, but it is normal for the top of the pistons to be black. You should have some wash (clean piston) around the edges from the fuel coming in from the ports. Is the sled all stock? Any pipes or can or anything else on it? If not, when you pull the carbs apart to clean, make sure the jetting is stock and you should be good to go unless you get into some really cold temps.

As far as testing the spark and stator, there is some testing in the manual but that hasnt been 100% for everybody. There have been people that have tested the stator when its cold and it tests fine but replace the stator and the sled runs fine. My 97 Mach 1 was similiar, once the sled warmed up, it wouldnt pull rpms, replaced the stator and was all good. Here again, I dont think thats your issue either. Usually for the most part, they work or dont. Some do have issues like mine that they will run but they wont pull rpms and will break up on the top end.

Curious, has your CDI been relocated or is it still under the motor?
 

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You adjusted your oil pump correctly.

When the pumps get older after years of use, they typically start injecting more oil than needed. The reason for the arm not going back is usually due to a divot worn into the pivot shaft. The pumps are non rebuild able.

Usually the arm will return all the way back when the engine is running so I've never used an additional return spring. (No need)

I`ve never heard of an oil cable breaking so forget about that unless you see some obvious reason for a new one. They are available as carb and oil cable assemblies.

I don`t know but it sounds like you start this sled often and it idles quite frequently…STOP!!! J Seriously, if you have bad gas or old gas, it will foul. I used to always have issues on my first ride, usually on my way to the gas station.

With a fresh tank and a good run, I never fouled another plug the rest of the season.
 

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I would do a thorough carb clean. Verify all jetting and needle positions. Check float heights and needle and seats. Could be just floats sticking
 

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Discussion Starter · #17 ·
Update.. All 3 Rave Valves missing O-Rings and sticking.. Carbs needed a good cleaning too.
Hoping correcting these issues will fix my fouling plugs issue. Will know more when my parts come in...
Thanks everyone for your advice.
 

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Discussion Starter · #18 ·
Sled is running much better now..
Any tips on cracking my breather box open. I don't think it's ever been open and needs a good cleaning..
Thanks
 
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