Did you take the inner pto seal and ring off of the 99 crank.
mach z experts-HELP!!!!!
My buddy has a 98 mach z that wont rev over 6000 rpm.The motor is a fresh rebuild.It has a 99 crank in it which shouldnt matter,everything else is off a 98.
It runs fine from an idle to about 6000 rpm real snappy but falls on its face anthing over 1/2 to 3/4 throttle.
Things we have tried:
1) pulled the motor and went through the entire wiring harness to make sure there are no shorts
2)new stator
3)tried two different cdi(yes the dess was programed for each box)
4)new fuel pump
5)tried two sets of coils
6)pulled and checked clutches
7)cleaned carbs 3X's
8)checked,plug caps,cdi,coils,stator,kill switch ect ect with ohm meter
9)plugged cdi box directly into stator bypassing the harness
We think the timing might be the problem but arent sure.When we dial indicated the mag side piston to the spec. we found the tab on the flywheel was not centered under the pick up as it should be.We changed flywheels and we got the tab to line up but the timing mark was way off and no where near the window in the case.Do you have to run a 99 flywheel with a 99 crank or are they all the same as far as timing goes?My buddy is ready to part this thing out and buy a new phazer of all things!!!!!
It runs fine from an idle to about 6000 rpm real snappy but falls on its face anthing over 1/2 to 3/4 throttle.
Things we have tried:
1) pulled the motor and went through the entire wiring harness to make sure there are no shorts
2)new stator
3)tried two different cdi(yes the dess was programed for each box)
4)new fuel pump
5)tried two sets of coils
6)pulled and checked clutches
7)cleaned carbs 3X's
8)checked,plug caps,cdi,coils,stator,kill switch ect ect with ohm meter
9)plugged cdi box directly into stator bypassing the harness
We think the timing might be the problem but arent sure.When we dial indicated the mag side piston to the spec. we found the tab on the flywheel was not centered under the pick up as it should be.We changed flywheels and we got the tab to line up but the timing mark was way off and no where near the window in the case.Do you have to run a 99 flywheel with a 99 crank or are they all the same as far as timing goes?My buddy is ready to part this thing out and buy a new phazer of all things!!!!!
1 - 14 of 14 Posts
My buddy built the motor so im not sure.I know he changed the outer bearings and seals on the crank.I think he pressure tested the motor and said it was ok.Why do ask about the inner pto seal and ring,could there be a problem there?Did you take the inner pto seal and ring off of the 99 crank.
The 99 crank had a seal on both sides of the outer pto bearing packed with grease.The 98 did not have this and the case is not cut to take the inner seal.Maybe if it was installed in the 98 case it would be real tight causing your rpm problem.I seen stranger things happen.
hey,
just a thought, are the rave cap adjusters tightened all the way down, this would keep it from revving? It is something that could be done during the rebuild not knowing that they don't need to be tightened all the way down.
let me know.
Gutz
just a thought, are the rave cap adjusters tightened all the way down, this would keep it from revving? It is something that could be done during the rebuild not knowing that they don't need to be tightened all the way down.
let me know.
Gutz
Nothing to do with it, they all come tight from the factory anyways.hey,
just a thought, are the rave cap adjusters tightened all the way down, this would keep it from revving? It is something that could be done during the rebuild not knowing that they don't need to be tightened all the way down.
let me know.
Gutz
Guess I would do the obvious and start on the clutching especially the secondary such as a stuck helix, broken spring or missing buttons.
I checked both clutches,even tried it with no drive belt on and it still wouldnt rev.It has brand new v force reeds.I checked and cleaned the rave valves and they are not tightened down.Its gotta be electrical but i dont know where else to turn,we tried everything.Would a 99 crank with a 98 flwheel cause any problems?We tried two different pick up coils. The timing is way off when we check it with a timing light,but it could be because it starts misfiring at around 5800 rpm.Looks like were gonna part it out soon if we cant figure it out.
I know how frustrating these problems are. I chased a plug fouling issue for almost a year, ended up it was all 3 coils.
First thing I would do is go through and methodically check each component needed to make engine run...
At this point its a good idea to go back and check things that you have already checked.
Compression and leakdown
Next is motor getting adequate fuel? It sounds like its getting enough on bottom end, kinked line, I have seen a problem similar to yours on a mxz 800 where the gasket between the carb and the funnell was sucking in air under higher load and this caused the motor to bog above 5000rpm.
Check the rave valves again. Are they opening up at all?
I know this sounds dumb but check to make sure there isn't anything plugging the exhaust.
You said you pulled the clutches off and just ran the motor so that has eliminated the clutching.
One last thing before you go to electrical. Is the fuel good? I have seen time and time again people say its good and it was bad. Try fuel from another source. The mach z's are touchy with old fuel.
Ok, if nothing has been determined at this point you can move on to the electrical.
You replaced the stator so if the motor runs most likely you don't have a problem there unless your headlights are dim then it could be a stator/ voltage regulator problem. If you have good headlights its a pretty good indication you are getting good power from the stator.
I would be highly suspicious of the coils on this sled. Check to make sure grounds on coils are good, I have seen loose connections with these a lot. I had 3 coils all work and test ok but over 6000 they had a week spark and caused fouling in random cylinders. Try gapping plugs closer than recommended you can usually tell then if it is week spark because spark will jump the smaller gap.
Check plug cap resistance again, I believe it shouldn't be greater than 4 ohms or maybe it was .004, can't remember.
Check to make sure you are getting 12 volts out of your voltage regulator.
Chances are the wiring harness is ok, 98's had a fraying problem under the motor, but if you have had it out I assume you checked all the wiring there.
Disconnect everything going to handlebars to eliminate any shorts.
Check the dess post I have heard of those causing shorts in the ignition.
If still nothing has turned up your last option is timing. I have always checked timing by putting pto piston at tdc and marking the primary and also a mark on the support in line with the mark on your clutch. Then hook up your timing light and go off of these marks. I am not sure of timing specs on the 98, but what they are and what you see with timing light should be close if not dead on. It doesn't take much timing to through off your rpm. I set up a twin once with the timing way advanced and it made quick rpm out of hole but we couldn't get it to rev over 6900 rpm with that much advance. It sounds like this could also be your problem.
Honestly it has been so long since I have played with the timing on a mach z that I can't remember if its possible to adjust timing at the flywheel or not. I know I could also do it with the programmer, but it is limited to +- 6 degrees I believe. Is the keyway position in relation to the postion of the rods the same on a 99 as a 98?
Don't let it beat you hang in there there is only so much it can be and it sounds like your on your way to eliminating the problem.
Goodluck shoot me a p/m if you have any questions, I have a lot of the 809 mach z stuff still, coils, cdis, volt reg. etc.
Jeff
First thing I would do is go through and methodically check each component needed to make engine run...
At this point its a good idea to go back and check things that you have already checked.
Compression and leakdown
Next is motor getting adequate fuel? It sounds like its getting enough on bottom end, kinked line, I have seen a problem similar to yours on a mxz 800 where the gasket between the carb and the funnell was sucking in air under higher load and this caused the motor to bog above 5000rpm.
Check the rave valves again. Are they opening up at all?
I know this sounds dumb but check to make sure there isn't anything plugging the exhaust.
You said you pulled the clutches off and just ran the motor so that has eliminated the clutching.
One last thing before you go to electrical. Is the fuel good? I have seen time and time again people say its good and it was bad. Try fuel from another source. The mach z's are touchy with old fuel.
Ok, if nothing has been determined at this point you can move on to the electrical.
You replaced the stator so if the motor runs most likely you don't have a problem there unless your headlights are dim then it could be a stator/ voltage regulator problem. If you have good headlights its a pretty good indication you are getting good power from the stator.
I would be highly suspicious of the coils on this sled. Check to make sure grounds on coils are good, I have seen loose connections with these a lot. I had 3 coils all work and test ok but over 6000 they had a week spark and caused fouling in random cylinders. Try gapping plugs closer than recommended you can usually tell then if it is week spark because spark will jump the smaller gap.
Check plug cap resistance again, I believe it shouldn't be greater than 4 ohms or maybe it was .004, can't remember.
Check to make sure you are getting 12 volts out of your voltage regulator.
Chances are the wiring harness is ok, 98's had a fraying problem under the motor, but if you have had it out I assume you checked all the wiring there.
Disconnect everything going to handlebars to eliminate any shorts.
Check the dess post I have heard of those causing shorts in the ignition.
If still nothing has turned up your last option is timing. I have always checked timing by putting pto piston at tdc and marking the primary and also a mark on the support in line with the mark on your clutch. Then hook up your timing light and go off of these marks. I am not sure of timing specs on the 98, but what they are and what you see with timing light should be close if not dead on. It doesn't take much timing to through off your rpm. I set up a twin once with the timing way advanced and it made quick rpm out of hole but we couldn't get it to rev over 6900 rpm with that much advance. It sounds like this could also be your problem.
Honestly it has been so long since I have played with the timing on a mach z that I can't remember if its possible to adjust timing at the flywheel or not. I know I could also do it with the programmer, but it is limited to +- 6 degrees I believe. Is the keyway position in relation to the postion of the rods the same on a 99 as a 98?
Don't let it beat you hang in there there is only so much it can be and it sounds like your on your way to eliminating the problem.
Goodluck shoot me a p/m if you have any questions, I have a lot of the 809 mach z stuff still, coils, cdis, volt reg. etc.
Jeff
Nothing to do with it, they all come tight from the factory anyways.hey,
just a thought, are the rave cap adjusters tightened all the way down, this would keep it from revving? It is something that could be done during the rebuild not knowing that they don't need to be tightened all the way down.
let me know.
Gutz
Guess I would do the obvious and start on the clutching especially the secondary such as a stuck helix, broken spring or missing buttons.
[/quote]
I just want to make sure we are talking about the same piece, it is #15 and it SHOULD NOT be tight, 1-2 complete turns or more, out from tight.
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Nothing to do with it, they all come tight from the factory anyways.hey,
just a thought, are the rave cap adjusters tightened all the way down, this would keep it from revving? It is something that could be done during the rebuild not knowing that they don't need to be tightened all the way down.
let me know.
Gutz
Guess I would do the obvious and start on the clutching especially the secondary such as a stuck helix, broken spring or missing buttons.
[/quote]
I just want to make sure we are talking about the same piece, it is #15 and it SHOULD NOT be tight, 1-2 complete turns or more, out from tight.
[/quote]
Yep #15 the red button, they all come tight from the factory. You can set it wherever you want, wont make enough difference to say so. If you want to change the opening or closing you need to change the spring.
I would try loosening them, they are adjustable and are not suppose to be tight, the spring is of a particular tension, but they still can (Should) be adjusted.
Gutz
Gutz
I just looked and the mag end is a different part number from 98 to 99. I know I built a race motor a few years ago and he had 98 and 99 parts mixed and had problems. We had to switch the ignition cover and cdi to 99 to make it work. I believe the 99's trigger is located differently than the 98 witch would put the flywheel key in a different location. this could be why there is a difference in part numbers. You could probably change the mag end of the crank back to a 98 or try putting a 99 ignition cover on it. Dial indicate tdc on the mag and check your trigger location. If it's way off that could be your problem. Hope this helps, Dave.
Well after pulling the motor twice,going through the entire wiring harness,new stator,new cdi,new fuel pump,new dess cord,new pickup coil,two different flywheels,new reeds,two sets of coils........we finally got it running.You guys arent gonna believe what the problem was.A kinked vent line for the gas tank.After trying everything we could think of with no luck i took the gas cap off and started it up and it reved to 8500 no problem.The vent line was all coiled up under the dash and must have been kinked.We straighted and shortened the vent line and it runs great.Unbelievable!!! Thanks to everyone who tried to help us with this,let it snow!!!
1 - 14 of 14 Posts
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