I'm glad you checked, that was the nasty thought I'd had earlier.
Can you put marks say every 10 degrees or so on your clutch, and throw the timing light on it and see where you are?
Old school, big power
- Thread starter mattymac
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I'm glad you checked, that was the nasty thought I'd had earlier.
Can you put marks say every 10 degrees or so on your clutch, and throw the timing light on it and see where you are?
I did it with the motor in the chassis it wasn't very precise but there weren't any big red flags when I checked it so I figured it had to be close
Ya I have twisted a few cranks my self through the years and thats why all my cranks get welded all the way across now days.
On your ignition. You were originally setting this up to use a reprogrammed ZR900 box & stator correct??
With the T-cat set up you have good spark but not with the ZR. It sounds like a bad Stator or CDI box with the ZR set up to me. With the T-cat set up the timing is probable not close.
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Download this service manual and go to page 22 of it in the pdf. It will show you the piston location in thousands of a inch VS crankshaft degree's so you can put your dial indicator in it and check to see where your triggers on the flywheel are actually at.
http://countrycat.com/ccstore/kbase/snow/2005/Section2.pdf
I would also get a heavy piece of wire that wont vibrate like crazy and bolt on so its to your clutch and mark your clutch every few degree's and put a timing light on it. Check each cylinders timing.
Let us know what you find out.
http://countrycat.com/ccstore/kbase/snow/2005/Section2.pdf
I would also get a heavy piece of wire that wont vibrate like crazy and bolt on so its to your clutch and mark your clutch every few degree's and put a timing light on it. Check each cylinders timing.
Let us know what you find out.
Yeah, I was running a twin reprogrammed CDI first, could NOT get spark, tried another stock 900 twin CDI just to see if it would spark, same result, nothing. Also tried 3 different twin stators, still the same, two used and one brand new one.
Blaine Pertler and I had a conversation and his thought was there is a smaller capacitor in the twin CDI and with three triggers it doesnt have enough time to recoup the electrical power between the triggers and spark (33% more drain on it with the third trigger) which sounds plausible to me, but Scott has run this before same system before successfully, so that puts that theory into question.
When I installed a twin FLYWHEEL with the twin electronics I got spark! (which really didnt surprise me much)
I have a 2001 thundercat in my shop right now that im using for parts/info from a good buddy.
The twin 900 I have on my bench, I found out that the initial (static) timing or indexing of the flywheel is at 43 deg BTDC, which matched the number what scott had come up with (after I got a good un-twisted flywheel)
The TCat is set at 39 degrees BTDC, I have run both of these flywheel timing advances (and litterally all the way down to as low as 15 degrees just to see) the motor runs pretty much the same.
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With my timing set where it was in the video, it calcs out to .342" of piston travel btdc to get the leading edge of the trigger on the flywheel where it meets the center of the timing sensor.. the manual says 30 degrees is .249" and that's as far out as it goes and it's not linear, it should be in the upper 30 degree range for static timing
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OK, Im not sure how the NOI of the T-cat ignition would compare to the older NCI.
I just thought of some thing. Did you modify or change the wiring for the TPS sensor?? If your sled was a twin carbed sled the wire harness would have this in it. If it was a EFI I would have no clue on the wiring.
Throttle safety switch in the handle bars??
When we get a electrical troubled sled the first thing we do is bypass every thing but the kill and ignition. We have a dummy harness made up.
The piston travel will change as the crank is rotated because the con rod is off center. The length of the rod will change the travel as well.
Follow what the chart is in the book. If you match it up with a degree wheel and indicator reading you will know which way is correct.
NCI/NOI is just the grounding circuits for the ignition system, you will either have no spark or noway to kill the spark via the kill switches, TSS has been disconnected, same results, sled was carbed, so wiring is the same. TPS, since it won't rev up the TPS isn't really doing much at this point, runs the exact same with it in hooked.
I understand that timing in piston travel isn't the same all the way around that's why I posted that along with the measurements from where I'm at and what the book says.
I understand that timing in piston travel isn't the same all the way around that's why I posted that along with the measurements from where I'm at and what the book says.
I just double checked the flywheel triggers with my dial making new degree marks on my clutch, the triggers line up dead on at every 120 degrees of crank rotation... I mean dead on! Mag,Center,Pto. With the timing light it seems like it would light up 25 degrees btdc but the flash didn't seem very consistent either! It acts like I have an erratic spark. But my timing light is pretty ancient and it hasn't been used in 15-20 years I wish it would rev up more but it just won't. Next step is swap my modded flywheel to the stock tcat I have in my shop
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Im just throwing this out here. You didnt leave shop towels in the pipes did you?? I have seen that once too.
Personally I would make up a dummy wire harness just to make sure its not some thing with the chassis wiring. Things can get cut and grounded when working on a project like this and you dont even know it happened until you have a problem.
Im not that familiar with the NOI ignition but if the CDI box did not read the TPS wouldn't it not let the engine rev up?? I know with the old NCI ignitions if the magnets on the carb was not set properly it would not let the engine rev up. With those ignitions I just by passed the carb safety switchs.
Intermittent, erratic spark sounds like a Stator. I had one drive me nuts before I figured that one out. That was a 96 Zrt600.
Personally I would make up a dummy wire harness just to make sure its not some thing with the chassis wiring. Things can get cut and grounded when working on a project like this and you dont even know it happened until you have a problem.
Im not that familiar with the NOI ignition but if the CDI box did not read the TPS wouldn't it not let the engine rev up?? I know with the old NCI ignitions if the magnets on the carb was not set properly it would not let the engine rev up. With those ignitions I just by passed the carb safety switchs.
Intermittent, erratic spark sounds like a Stator. I had one drive me nuts before I figured that one out. That was a 96 Zrt600.
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It almost sounds like spark scatter kind of like the 3.4 toyota v6 or waste spark as they say or M series type
ignition. Too many wires to the coils? Thought about this over night, after listening to the vid could it be
something causing an intermission, it seems to want to run, is there a rectifier or something just down stream of the triggers it's like there is something stopping current when it starts to build momentum, a bad ground maybe? A friend of mine inherited a old nova and it always had dim lights, it started fine, ran fine
we looked and looked to find a problem. He sold it, that guy had it checked and there was a ground strap
that was at the bottom of the fire wall that mounted to the engine block, once it was bolted back to the block all was well, no more dim lights.
ignition. Too many wires to the coils? Thought about this over night, after listening to the vid could it be
something causing an intermission, it seems to want to run, is there a rectifier or something just down stream of the triggers it's like there is something stopping current when it starts to build momentum, a bad ground maybe? A friend of mine inherited a old nova and it always had dim lights, it started fine, ran fine
we looked and looked to find a problem. He sold it, that guy had it checked and there was a ground strap
that was at the bottom of the fire wall that mounted to the engine block, once it was bolted back to the block all was well, no more dim lights.
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Been a long summer, didnt have much extra time to dedicate to this project for a while but I have the last couple days.
Heres what I have found out:
The problem I had with my setup is what I always thought based on the way my engine acted, erratic/jumping spark. No matter where I would index or set the flywheel/ignition in relation to crank position when I was able to get it to fire up and run the actual timing wouldnt change much on the light and my timing marks.
This led me to try and figure out the "why" not so much the "just get it running" approach.
I had tried what Scott and his dad did when building another engine that involved using a polaris flywheel (older XLT) with a riveted hub setup from an older 900 tcat. After some machining I had a perfectly setup modified new flywheel setup which they got to work properly. I had the same result as before it didnt want to run.
I finally tried my tcat ignition but finally with a tcat ignition sensor (so now for the first time 100% tcat ignition) which is what everyone in the past had run with great success . The appeal of running a newer twin reprogrammed ignition was for many reasons, availability, custom programming, and potentially engine reverse! Once I went 100% tcat my engine came to life, and ran better than it ever had! Granted it was over 50 degrees off on the timing but now I could start to make forward progress!!!
Ignition parts incompatibility is what had me pulling my hair out trying to get this thing going correctly. With Scott and his dads older engine setup with the twin ignition this is what they ran and it worked, they later built another one after the problems I had in which they then had the same issues as I did (two twin ignition triple engines not working and only one that was) IMO the one that worked is the oddball, for why it works is honestly still a mystery! The theory is that the twin CDI has smaller discharge capacitors internally that in twin configuration has more time between sparks to recharge, with a triple cylinder setup, you have more draw with a second external ignition coil and less time (120 degrees of crank rotation vs 180, along with three sparks per 360 degrees of crank rotation). We're assuming that the one running twin CDI just had stronger capacitors although they changed this engine to the polaris xlt flywheel and they got it to run whereas I mirrored their new setup with the same results I had previously. This is only theory maybe right maybe wrong. I just know originally 2 out of 3 didnt work.
The key for my engine was the trigger sensor itself. I had to build a custom bracket for inside the mag housing for the tcat sensor to bolt in the twin case end. It is thinner than id like but it still keeps me from cutting the big hole on top of the mag housing and mounting the sensor which was a goal for me.
All that along with yet another keyway cut in my flywheel (four now) and were in business other than just waiting for some decent snow!
Ive built a variety of different engines, most were always straight forward, ive probably learned more on this venture than any other engine build but I still feel this engine has its place on the snow for the HP junkies! In the future the Cutler one piece cast case is the way to go IMO, along with a complete 100% tcat ignition with a retapered flywheel hub to prevent the keyway from sheering due to incorrect taper angles, preferably newer tcat cdi with a TPS sensor and rackslide carbs, m1000 pistons, jaws pipes and a good chassis. Triple hood and belly pans are a plus but with a taller twin hood or trimming the stock twin hood it will all fit under there!
Heres what I have found out:
The problem I had with my setup is what I always thought based on the way my engine acted, erratic/jumping spark. No matter where I would index or set the flywheel/ignition in relation to crank position when I was able to get it to fire up and run the actual timing wouldnt change much on the light and my timing marks.
This led me to try and figure out the "why" not so much the "just get it running" approach.
I had tried what Scott and his dad did when building another engine that involved using a polaris flywheel (older XLT) with a riveted hub setup from an older 900 tcat. After some machining I had a perfectly setup modified new flywheel setup which they got to work properly. I had the same result as before it didnt want to run.
I finally tried my tcat ignition but finally with a tcat ignition sensor (so now for the first time 100% tcat ignition) which is what everyone in the past had run with great success . The appeal of running a newer twin reprogrammed ignition was for many reasons, availability, custom programming, and potentially engine reverse! Once I went 100% tcat my engine came to life, and ran better than it ever had! Granted it was over 50 degrees off on the timing but now I could start to make forward progress!!!
Ignition parts incompatibility is what had me pulling my hair out trying to get this thing going correctly. With Scott and his dads older engine setup with the twin ignition this is what they ran and it worked, they later built another one after the problems I had in which they then had the same issues as I did (two twin ignition triple engines not working and only one that was) IMO the one that worked is the oddball, for why it works is honestly still a mystery! The theory is that the twin CDI has smaller discharge capacitors internally that in twin configuration has more time between sparks to recharge, with a triple cylinder setup, you have more draw with a second external ignition coil and less time (120 degrees of crank rotation vs 180, along with three sparks per 360 degrees of crank rotation). We're assuming that the one running twin CDI just had stronger capacitors although they changed this engine to the polaris xlt flywheel and they got it to run whereas I mirrored their new setup with the same results I had previously. This is only theory maybe right maybe wrong. I just know originally 2 out of 3 didnt work.
The key for my engine was the trigger sensor itself. I had to build a custom bracket for inside the mag housing for the tcat sensor to bolt in the twin case end. It is thinner than id like but it still keeps me from cutting the big hole on top of the mag housing and mounting the sensor which was a goal for me.
All that along with yet another keyway cut in my flywheel (four now) and were in business other than just waiting for some decent snow!
Ive built a variety of different engines, most were always straight forward, ive probably learned more on this venture than any other engine build but I still feel this engine has its place on the snow for the HP junkies! In the future the Cutler one piece cast case is the way to go IMO, along with a complete 100% tcat ignition with a retapered flywheel hub to prevent the keyway from sheering due to incorrect taper angles, preferably newer tcat cdi with a TPS sensor and rackslide carbs, m1000 pistons, jaws pipes and a good chassis. Triple hood and belly pans are a plus but with a taller twin hood or trimming the stock twin hood it will all fit under there!
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Awesome learning curve! love guys thinking outside of the box! a lot of this make me respect how for out the box the triple technological was for it's time!
I think for me it really puts things into perspective on how the pioneers of this sport from decades to only just a handful of years ago changed this sport and how far ahead of their time they were! All of their outside the box thinking!
Dale Cutler
Chad Rebek
Brad Wursten
Dan Turin
Rich Tison
Gus Bhone (spelling?)
Olav Aaen
Bruce Kalhamer
Brent Linderman
Just to name a small handful, These guys IMO did some crazy off the wall thinking that was/is ahead of its time for this great sport that make doing projects like this seem like nothing compared to what they tackled over the years!
Found a lead on some cutler cases. I now have 3 sets of triple cases.
When I started this build from day one I always knew if there was an issue to be had it would be with the ignition.
I built a bracket in the case to hold a TCAT timing sensor that after all my headaches trying to get the twin reprogrammed ignition to work made the engine run the best that it ever had. There were two problems with it....
One: it had ZERO room for adjusting it to dial the timing in and all that could be relied on was the keyway slot in the flywheel or an offset keyway.
two: the TCAT timing sensor is physically bigger than the twin sensor, the cast threaded bosses in the twin case are narrower so getting a bracket to hold the TCAT sensor in the twin location made the bracket very thin and with the vibrations a motor of this caliber will produce I didnt trust it and figured one day it would eventually fail.
A cast style case addresses these issues, mainly the new bracket to mount the TCAT sensor back where the factory TCAT sensor goes but with the ability to rotate it externally a huge amount. THIS BRACKET IS KEY!
I will machine the cut and welded cases to accept this bracket and will end up with a more reliable, externally adjustable more secure setup to correct the issues with this problem that I faced with this project.
Im still running 90+% OEM arctic cat parts that are readily available (although crankshaft bearings are getting hard to find from what Im seeing.) When I had this crankshaft out I had it rebuilt with new bearings, PTO and MAG ends. Ill end up building another engine using the cut and welded cases I got from Scott just with a few slight modifications. Hopefully ill have it ready in time for some grass drags with a gutted, studded and slammed rail ive had for a while then possibly end up putting this motor in a PRO RMK.
When I started this build from day one I always knew if there was an issue to be had it would be with the ignition.
I built a bracket in the case to hold a TCAT timing sensor that after all my headaches trying to get the twin reprogrammed ignition to work made the engine run the best that it ever had. There were two problems with it....
One: it had ZERO room for adjusting it to dial the timing in and all that could be relied on was the keyway slot in the flywheel or an offset keyway.
two: the TCAT timing sensor is physically bigger than the twin sensor, the cast threaded bosses in the twin case are narrower so getting a bracket to hold the TCAT sensor in the twin location made the bracket very thin and with the vibrations a motor of this caliber will produce I didnt trust it and figured one day it would eventually fail.
A cast style case addresses these issues, mainly the new bracket to mount the TCAT sensor back where the factory TCAT sensor goes but with the ability to rotate it externally a huge amount. THIS BRACKET IS KEY!
I will machine the cut and welded cases to accept this bracket and will end up with a more reliable, externally adjustable more secure setup to correct the issues with this problem that I faced with this project.
Im still running 90+% OEM arctic cat parts that are readily available (although crankshaft bearings are getting hard to find from what Im seeing.) When I had this crankshaft out I had it rebuilt with new bearings, PTO and MAG ends. Ill end up building another engine using the cut and welded cases I got from Scott just with a few slight modifications. Hopefully ill have it ready in time for some grass drags with a gutted, studded and slammed rail ive had for a while then possibly end up putting this motor in a PRO RMK.
the cat 900 bearings are huge and very expensive.
On the Pro I can see the tq of this motor not doing well with the chassis as most of the motor compartment is cast aluminum.
On the Pro I can see the tq of this motor not doing well with the chassis as most of the motor compartment is cast aluminum.
Yeah the bearings arent cheap compared to other manufacturers but ive seen way more suzuki bottom ends go thousands and thousands more miles than a poo or a doo. I have seen MANY cat 7/8/900's go into the 5-7000 mile range on a stock untouched bottom end.
I was skeptical about doing a Pro RMK big triple build for the same reliability concerns but having a few conversations with Kurt at fastrax he claimed that the bulkhead of the pro is actually stronger than one from a IQR (which is known for WC triple builds) because of the triangulated over structure making the engine boxed in and in his opinion stronger. Its the suspension tunnel and drive components that need to be addressed.
Brad Wurstens 1620 billet pro seems to be holding up quite well but like all his builds they are 1st class.
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those pipes are ART and magic!
I own Glens sled now. He swapped back to a 1080 twin but I have the complete engine on a shelf. Two cranks. And a spare 1080. I’m not going that route tho. I’m going to run the same as Matty and go 1462 for inventory purposes. So I got a running 1080 with a spare cylinder for sale
Laguns 1404 would have ran with the 1800 if it wasn’t in a stock king chassis. He had the clutching damn near perfect. The 1800 just couldn’t keep belts or clutches on it. And that was without the dual stage nitrous working.
I gotta get my 1010 rev up and running first, then I’ll turn attention to the triple. I woulda went 975 but I don’t have any good cylinders right now and I have three 1010’s on the shelf. Gotta figure out pipes. The 1200 twin pipes won’t give me any top end but it’s the only set I have that are fitted. My 860 NPP single(for a rotax 860) isn’t gonna be enough for the 1010 I don’t think. And I don’t wanna pop it first ride out.
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