|
|
Post by mrmotors on Dec 15, 2019 22:50:07 GMT -6
These guys on here giving you advice certainly know a LOT more about it than I do. I have been reading this complete thread as it has played out and I have a couple questions for you, I think one of the other guys hit on this earlier. I sounds to me like the thing is not shifting correctly and keeping it "bogged" down so to speak. Do you have the correct width drive belt? Is the belt going full travel in the sheaves, all the way up on the engine and all the way down on the secondary? Is the distance between the engine and the secondary clutch correct, center to center? Is the thing lined up correctly and are they parallel?? From the test you said you have just performed where it went to 8400, seems like there is a mechanical issue preventing it from doing so when put togehter. Maybe all these questions are things that are forgone conclusions, I am mostly just curious so that I can learn something too. Thanks.
|
|
|
|
Post by midniterupper on Dec 16, 2019 2:57:59 GMT -6
Wow! Excellent thinking! Thanks for your input, you have asked some very good questions and I really do appreciate your help. With this thread, I believe quite a few good folks will benefit from all the wisdom and helpful advice everyone has been sharing. This will help out all of us looking to gain the performance these Red sleds are capable of. The support throughout this Message Board has been nothing but professional, encouraging and overwhelming to say the least. A lot of these good guys have been on this Board for many years helping and assisting anyone who has a question on any aspect regarding these sleds. Many of you are legendary for sure! Thanks again to all of you for helping us Newbies, we do pay attention to what you say. We all respect and admire your accomplishments and dedication to our sport, especially your expertise in knowing these Rupps.
Okay, now onto your excellent suggestions from MrMotors. I gotta agree with you, for my motor to rev up so quickly to 8500 rpm without the belt on, there must be something wrong within the drive train. I need to mentally break down the system, thoroughly understand the function and demand of each component and see what needs attention. I always mark the clutches with black permanent marker to verify the shifting out of each clutch before each test run. I also use my heat gun the see what the temp is on each clutch. I think sometimes the clutch that may be producing extra drag will read a higher temp, due to the increased friction of possibly being out of alignment. I may have an issue there which is one of my questions too. I am not sure how to set the alignment offset of the Arctic secondary to my P-85 primary? I have been using a 3/8" straight bar placed between the secondary sheaves for verifying my alignment (the method used on Skidoos), and using a clutch offset bar of 7/16" (as used on the old Arctic cats) just to get an idea of where this secondary should rest at. But I don't have the newer style offset gage that is used on the Cats, wasn't sure if that offset would apply to our drivetrains. I'd like to pick one up to see if they may help with the clutch alignment/offset.
The drive belt I'm using measures 1.437" wide, it's the newer version of the belt Kevin is using. A little bit wider though. I was just reading some other threads on this site and Kevin mentioned he had to alter the center to center distance of the clutches due to using a wider than stock belt (1.250" vs. 1.375"). With this in mind now (and especially with your suggestion) I think I may need to move them closer also due to using even a wider belt. This dimension I will check. The marks on the clutches indicate the Primary is shifting out almost all the way to the extreme O.D. of the clutch, leaving a mark only about a 1/4" away from the outer edge of the clutch. I think it can still shift a little further out. Now on the Secondary, I'm not so sure. It appears to suck the belt all the way in, but I can't quite tell for sure as the marks are not consistent, they sorta just fade away. On the stand both clutches appear to be shifting out nicely. One thing I don't know is if the clutch offset is correct when fully shifted out? When I set the motor for alignment, I use the same method as used on the Skidoos (stuck on Bombardier knowledge, don't know what else to use!) where the front of the primary distance (X value) is increased by .060" over the back distance (Y value) from parallel. Like I mentioned, I am not sure if this procedure applies to our Rupps. Seems like it would as they both employ rubber mounts and the motors actually tweak back into alignment under load. Maybe this is part of the problem?
I will try to look at everything today to see what may be contributing to pulling my r's down. I think we are making progress here, the motor sounds so strong and cooperative. We'll stay at it and I'm sure together we will figure this thing out. Thanks again to all! Keep you posted!
|
|
|
|
Post by midniterupper on Dec 19, 2019 17:58:48 GMT -6
Well today I finally got a chance to take a look at the drive train on my sled. I first removed the drive belt and verified the engine is sitting straight and parallel to the jackshaft. With the drive belt removed, I removed both primary and secondary springs which allowed me to fully shift out both clutches to see exactly where the alignment should occur. I am not sure if I am on the right track with my alignment/offset method but this is how I did it.
I first used my trusty 3/8" square brass bar stock (18" long) and placed it in the very bottom of the secondary (and the primary) while I gently squeezed the secondary sheaves together to hold the bar in place. I used the edge of the bar to measure the distance at the front and back edges of the primary ensuring the motor is straight. Then I simulated both clutches being fully shifted out to verify the clutch offset is correct and the belt runs true and straight between the clutches. I wanted to make sure of this as I didn't have a reference gauge to use for setting the offset. I ended up turning a bushing out of aluminum and just faced it off until I got the correct length then I took off another .020" to allow for a little floating.
I then installed the drive belt and positioned it on the very outer portion of the sheaves and used a small C clamp to hold the sheaves and belt together. Then I separated the secondary sheaves sliding the belt all the way down to it's fully shifted position. This allowed me to measure and verify the actual belt deflection when the clutches are fully shifted to see if there is any binding or excessive play. This whole process was really cool to see, certainly helped me to better understand to constant changing positions of our drive systems. Pretty cool!
While I was playing around there, I rotated the secondary to feel the resistance while turning. It really isn't too bad at all. I could feel resistance that would sorta come and go from along the track area but nothing too bad. I think the resistance coincided with the lugs on the track as they rolled over the drive sprockets. No drive lugs are interfering with any idlers. I loosened the track just a tiny bit, realigned it and that actually seemed to aleviate some of the intermittent resistance. The track tension still seemed to be around 1" with 10 pounds down pull. I will leave that alone for now. I will still install the roller chain tensioners making sure to use the tie-bar method to keep the tension constant and eliminate the ratcheting problem I used to have. (Thank you very much!)
I'm content enough for now to leave the drive train components alone and just continue to focus on getting my rpm's up to the 8300 range. I swapped out some primary cam arms today. I went from 48.7 grams down to 44.6 but it didn't seem to effect the top rpm, both stayed around 7100 on the stand. I have some lighter arms to try tomorrow but with today's experimenting, I think I may have to perform a complete rebuild on the primary. Bought it used, maybe freshening it up may help it be more sensitive.
Let you all know what I find tomorrow, Thanks for any and all input!
|
|
|
|
Post by midniterupper on Dec 20, 2019 18:52:52 GMT -6
Okay, today I was able to play for a while. I swapped out several primary arms just to see what difference they make. I went from 48 gram arms down to 46 gram, down to 44 gram and finally down to 42 gram arms. The top rpm's varied (on the stand) ranging from 7000 (48 gr.) up to 7600 (42 gr.). I marked the clutches prior to every change with black marker. What was interesting was that the marks rubbed off at the top of the primary with the heavier weights at lower rpm. The marker wasn't wore off when I used lighter weights and gain rpm. It appears the primary doesn't fully shift out using the lighter weights even tho the rpm's are up. Also used a gram scale to verify the actual weights, some varied as much a a full gram! I made sure they weighed exactly the same before installing them. I ended up putting the 48 gram weights back in for now, as they were in the clutch on my last pass that had the highest speed. I'm still looking for a set of MR10's to try as well.
With that aspect of this adventure being temporarily satisfied, I then moved onto installing the roller tensioner set up for my drive chain. When I last played a bit in the snow here I could feel the chain rolling over the top sprocket again like I did before but not as severe. When I pulled the chaincase cover today I noticed some fine metal shavings in the bottom of the case verifying the chain was rolling over the top sprocket. I made another tie bar when I installed the new roller tensioner set up. It went together quite well, we'll see if it helps and holds up.
While I am in that area of the motor, I figure I would take a look at the magneto and timing situation. I pulled the flywheel and found no timing marks on it whatsoever. The stator plate has a tick mark on it which appears to coincide with one on the case. I used a dial indicator again setting it at .085" thru .100" but I didn't see an actual aligning mark anywhere in that area. I still have the marks on the Primary and case that I painted on a while back that I used to verify my timing. Just thought maybe there might be some indicator markings from the factory but I didn't see any.
I'm going to put her back together tomorrow and do a little playing in the snow. Kinda curious to see how everything responds!
|
|
|
|
Post by mrrupp1 on Dec 20, 2019 23:10:20 GMT -6
I think it’s funny how you lost speed with more rpm. I can’t wait to here how she runs in the snow. Keep the updates coming. Good luck . Clint
|
|
|
|
Post by midniterupper on Dec 21, 2019 17:38:08 GMT -6
Hey, Just a quick update of today's progress, another cool day in the shop! I played with the engine timing first of all. Scribed my original existing timing marks on the forward side of the stator plate and engine case. I can see them much better there. Then I rotated the stator ccw by the thickness of the scribed line, I would say about .006". I want to be conservative on the advance and ensure it is between the stock timing mark and the .100" advanced mark. I ended up using a piece of 14 ga. wire that I looped around the upper coolant hose hose fitting using the clamp to secure the wire on that end. The other end I cut and fit so it stays next to the primary where I scribed the timing marks. It works great and appears to be very accurate for verifying the timing, which is right between the two marks of .087" and .100". Thanks again to you guys for helping me out with that process, turned out to be fun and rewarding!
I had a chance to actually get the sled out after the work and play a little bit, What a Blast! The sled is very quick, no ratcheting whatsoever, and super responsive. These Rupp actually handle pretty good in the snow too. First time I had it in the deeper snow. Steered great, not terribly bad over the bumps and just plain fun to ride!
Gonna see what I can do to the sled tomorrow just can't stop now!
|
|
|
|
Post by Ruppsforever on Dec 21, 2019 20:05:16 GMT -6
Did you ever try a different tach ??
|
|
|
|
Post by Ruppsforever on Dec 21, 2019 20:06:55 GMT -6
Your tach might be off 1000 rpms.
|
|
|
|
Post by midniterupper on Dec 23, 2019 12:29:18 GMT -6
You know, you may be right with this tach. I ordered a recordable tach/water temp/ EGT gage for Christmas since I have been so good this year (it's my first!) so hopefully I can get more accurate readings. I'll use it primarily for testing then remove it for the races, don't need any more attention. I played around with the timing procedure yesterday just to gain a better feel for moving the stator plate and seeing the results with the timing light. I want to wait to really verify the timing using the new digital tach to ensure I am at the 6k mark. Sure has been fun! If they only had a class to actually make you go through the process. Maybe you can teach an old dog new tricks eh? Thanks again, Merry Christmas to all! Keep you posted.....
|
|
|
|
Post by Ruppsforever on Dec 23, 2019 15:53:16 GMT -6
So what kind of weights did you try ?? Comet weights ?? Merry Christmas to you too.
|
|
|
|
Post by midniterupper on Dec 23, 2019 16:18:53 GMT -6
Well, that's a great question. Right now I have the Comet A-2 (48.8gr.) arms in there and she is spinning happily at 7500 rpm, but that is using my same VDO Extreme tach. The A-2 is the arms I had in it when I got our fastest run at 67mph. Interestingly the tach did read 8500 when I ran it without the belt. I really don't trust it to be accurate at this point. Hopefully the new one will read better.
But back to your question regarding the arms I'm using. I've tried the Comet A-3 (40.4gr.) @7500rpm, Comet A-10 (40.2gr.) @7600rpm, C-1M (46.1gr.) @7500rpm. Also tried the Arctic Cat 502-44.5gr. @7000rpm. Also the Polaris 10MW (44.7gr.) @ 7000rpm.
Another thing I did notice you may find interesting. I played around with the sled in the snow here before I switched over the chain tensioner, had 7400 rpm on the tach. After installing the roller tensioner, my rpm increased another 100 rpm to 7500. That is with the A-2 arms in the clutch for both instances, no other changes on the sled. But when I loosened up the track just a tad to possibly reduce the rolling resistance even more, I didn't gain any increase in rpms.
We'll stay at it!
|
|
|
|
Post by mrmotors on Dec 23, 2019 20:27:10 GMT -6
So here is another question from all this, are you using only the aftermarket (VDO) tach for al your information? Do you have a known stock Rupp tach that is accurate?? I do know there are differences between the Kohler tachs and the liguid tachs. I don't know who tests or overhauls these things but Kevin Hasse might be able to tell you. I'm thinkin I would try and known accuarate tach and see what it says..
|
|
|
|
Post by mrrupp1 on Dec 23, 2019 20:34:37 GMT -6
Do you think the sled is faster with the set up you have now?
|
|
|
|
Post by midniterupper on Dec 24, 2019 9:16:57 GMT -6
Good questions regarding the VDO tach. With the new one on it's way, I'll probably wait for that one to see what readings we get with that. It'll help with jetting for sure and now we can even monitor the water temp too. The stock Rupp tach never did work when I first hooked everything up, but I kinda expected that with the sled being a basket case when I bought it.
I do "feel" the set up we are using at the moment is actually faster but I need to get someone out there with the radar gun to verify it. It could even be that it's faster from just being on snow!
Probably no time to play with it today being Christmas Eve, but it allows me time to do more reading and note reviewing, I love doing that. You guys have given the gift of your knowledge this year. Man, I sure do appreciate you! Hope you all have a great New Year ahead too, looking forward to all the Rupp adventures ahead. Till next time.....
|
|
|
|
Post by mrrupp1 on Dec 24, 2019 20:20:25 GMT -6
Can’t wait to here what she’ll run now. I hope everybody has a Merry Christmas and a Happy New. Clint
|
|
|
|
Post by midniterupper on Dec 29, 2019 15:55:01 GMT -6
Well, I finally had a chance to install the Koso EGT, Tach and water temp gage (Model BA006B00). I purchased it from EGT directly, paid about $100.00 less from them compared to any other source. Came to around $348.00 with shipping and the Avenger probes. The install was pretty simple, took about 2 hours to hook everything up. BUT this unit does not record, give great readings and alarms for high temps that you set yourself but does not record high temps or RPM.
Kinda disappointed with that but I can reinstall the VDO recordable tach onto the machine. The RPM's are reading the same between the two, nice for the digital effect but I love being able to record the run for playback in the pits.
So now I am back to playing with RPM's. I have an idea to try just for grins and giggles, see what you guys think about it. With my RPM's not getting where they should be as the primary problem. The motor will reach 8400 when the drive belt is off. What if I remove the drive chain and run the motor only driving the secondary clutch and jackshaft? I'd be curious if the RPM will climb up to 8300...
I'll try it when I get a chance. Keep you posted!
|
|
|
|
Post by Ruppsforever on Dec 29, 2019 20:16:52 GMT -6
What pulse setting do you have these tachs set on ?? Been several years since I set the one on my Magnum. I'd have to check my old notes. Is there something really wrong with your clutches or belt ?? I would like to see a picture of your setup. Is your belt super loose ??
|
|
|
|
Post by midniterupper on Dec 30, 2019 7:53:14 GMT -6
Hi there, good to hear from you, hope all is well with you. On the tachometers, the VDO extreme has dip switches inside the cover. Of the 4 switches, I have set them for a 12 cylinder - 6 pulse signal input so the actual switch position is #1,2,3 is on and #4 is off. It took me a couple of days of fooling around with the switch positions in order to register the correct rpm. I didn't have any info on the Xenoah motors and ignition systems so it was just trial and error until I got it. It reads nicely, shows idle at 1800, engagement at 5300 and topping out at 7500 rpm. I am using the stock tach leads from the motor which seem to be good though the stock tach no longer works at all when it is hooked up.
Now on the Koso unit, it has to be programmed to read the signal pulse. The setting I am using is #2 which is for a 2 cycle, 2 cylinder with 1 rpm signal per revolution. The installation seemed easy enough, I used the same two leads for the tach and it is reading the same rpm's as the VDO tach. It tops out at 7600 rpm so it may be a bit more accurate. The water temp however reaches 150 if I let it run too long. Temps here right now are rather warm for this time of year, around 40 degrees. I will keep an eye on the running temp, try to maintain 140 as you mentioned earlier. Haven't had an opportunity lately to make any test runs to see what my exhaust temp is, pretty sloppy conditions. Looking forward to seeing them, plugs appear rich.
Regarding the belt deflection, I am not sure where to set it at. I have at at about 1"- 1 1/8" deflection and my clutch distance is about 10 1/2". I had to move the engine back a little bit in order to get that distance, I think with my original secondary I had it at 11". The belt has a little freeplay in it for the primary to keep it from creeping and bringing down the rpms at idle. When I put the sled on the stand, the track always rolls softly at idle, comes to a stop when I set it down. The belt is new, it's a Dayco XTX5032, measures at 1.412" wide and 45 7/8" long.
When I rotate the secondary with the belt off, it turns easily and smoothly without excessive resistance, especially with the track tension reduced. This one has me puzzled for sure.....
|
|
|
|
Post by midniterupper on Dec 30, 2019 8:11:35 GMT -6
You know, one thing I may have failed to mention about this rpm problem that may contribute to solving this mystery. The rpm's have stayed consistent at around 7000-7500 throughout the process. When first starting out I had the 102C primary and the OEM secondary from Rupp using a 30 degree helix and 11# preload. All with a new belt. The rpm stayed around the same range. Sled topped out at about 56 mph consistently at 7500 rpm.
Changed the primary to the P-85 and the secondary to the Cat reverse using a yellow spring set at 12# and a 53 degree helix, and of course the new belt. Rpm's stayed the same but the top speed increased immediately to 61 mph. With a little tweaking it is now topping out at 67 mph even though the rpm's are at 7500.
Just a little more information to think about. Even with the drive train changes, the rpm's still stay the same overall. Kinda bazzare isn't it? She sure sounds strong! Can't wait to get it figured out.
Thanks again to the Rupp community!
|
|
|
|
Post by Ruppsforever on Dec 31, 2019 19:18:39 GMT -6
Hopefully someone else chimes in with an idea because I'm stumped. I've ran into lots of stuff over the years but nothing like this. Is that pipe still restricted or something ?? Too much main jet but you ruled that out. Needle and Seats shot ?? Do you still have that dial a jet thing on the bowls ??
|
|
