Hi guys,
I recently put in some gyt pipes in my 94 vmax 600. I put 153.8 main jets, 2 q8 nozzles, and the needle clip is set in the middle with a washer on top and on bottom of the clip. I read that it should be in position 2.5 when using gyt pipes, and 2.5 is what the carbs are supposed to be set at from factory. (by the way is it normal my needle only has 3 positions the clip can go in?)
I have 20/37 gears. Secondary set to a2.
2 issues I'm running in to.
1 is that at full throttle I'm not revving to 8000 rpm. My machine had this problem even before putting the pipes on. not sure what the problem is. I'm guessing clutching?
2 with the gyt pipes installed I find the secondary shifts too fast, like the machine is always shifting into overdrive.
Keep in mind that the 94 I have has in internal helix on the secondary, not an external one like the 95-96 and newer.
What specs do you guys have for clutching while running gyt pipes for a 94 600?
I've also been told that I can swap both clutches with the 95-96 style for better performance and easier to find tuner parts for, like different weights and helix. My problem is the secondary from the 95 is too long for the jackshaft on the 94. I was told it should fit though. Any thoughts?
I recently put in some gyt pipes in my 94 vmax 600. I put 153.8 main jets, 2 q8 nozzles, and the needle clip is set in the middle with a washer on top and on bottom of the clip. I read that it should be in position 2.5 when using gyt pipes, and 2.5 is what the carbs are supposed to be set at from factory. (by the way is it normal my needle only has 3 positions the clip can go in?)
I have 20/37 gears. Secondary set to a2.
2 issues I'm running in to.
1 is that at full throttle I'm not revving to 8000 rpm. My machine had this problem even before putting the pipes on. not sure what the problem is. I'm guessing clutching?
2 with the gyt pipes installed I find the secondary shifts too fast, like the machine is always shifting into overdrive.
Keep in mind that the 94 I have has in internal helix on the secondary, not an external one like the 95-96 and newer.
What specs do you guys have for clutching while running gyt pipes for a 94 600?
I've also been told that I can swap both clutches with the 95-96 style for better performance and easier to find tuner parts for, like different weights and helix. My problem is the secondary from the 95 is too long for the jackshaft on the 94. I was told it should fit though. Any thoughts?
Not revving to 8k: Without knowing the past life of the sled and how well it has been maintained, I would suspect the clutches need some attention and probably should be fully serviced. Also check all bearings from behind the secondary clutch all the way around to behind the speedometer drive unit, then all the bearings in the skid as well. Make sure the skid is aligned in the tunnel/track, and that the track isn't rubbing anywhere on the tunnel or suspension, except the hyfax.
Primary clutch swap: If you have the original primary, you have many of the same tuning options as later primarys. Weights interchage. Rollers interchange with those of the same pin diameter, yours should be 8mm pin, later clutches use a 9mm pin. Roller diameters were made in at least 4 sizes for tuning options. Springs are matched to the cover style, short cover or tall cover. The tall covers were introduced with the 1998 SRX, and some tall cover springs are available in higher force specs than the highest of the short cover springs, so these may be more suited your GYT twin pipe sled. You can swap out the complete clutch to get the tall cover setup, or you can install the tall cover and spring on a short cover clutch.
Secondary clutch swap: I believe you have to replace the jackshaft to the 95-96 version as well as the clutch. The 95-96 clutch was a popular upgrade for the 94's, with a search here on TY, there should be plenty of info to help with the swap.
That's all I have for you at this point, other than if your engine is running decent but you are not making rpm, gotta figure that part out. If clutches or other drive related areas are part of the problem, they need to be serviced before making fine-tuning changes.
Primary clutch swap: If you have the original primary, you have many of the same tuning options as later primarys. Weights interchage. Rollers interchange with those of the same pin diameter, yours should be 8mm pin, later clutches use a 9mm pin. Roller diameters were made in at least 4 sizes for tuning options. Springs are matched to the cover style, short cover or tall cover. The tall covers were introduced with the 1998 SRX, and some tall cover springs are available in higher force specs than the highest of the short cover springs, so these may be more suited your GYT twin pipe sled. You can swap out the complete clutch to get the tall cover setup, or you can install the tall cover and spring on a short cover clutch.
Secondary clutch swap: I believe you have to replace the jackshaft to the 95-96 version as well as the clutch. The 95-96 clutch was a popular upgrade for the 94's, with a search here on TY, there should be plenty of info to help with the swap.
That's all I have for you at this point, other than if your engine is running decent but you are not making rpm, gotta figure that part out. If clutches or other drive related areas are part of the problem, they need to be serviced before making fine-tuning changes.
A couple of bucks
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What are the RPMs with no belt on?
I checked the clutches. The primary seems good. No ripples in the weights, no slack in the rollers. Sheaves move in and out nice. Secondary was taken apart. Helix looks good. Spring looks good. Was set to a2 for a 94 600 like the manual says. Jackshaft bearings are good, no slack, turn nice, the gear box was opened and bottom gear was changed. Now I have gears 20/37 for a 94 600 like the manual says. Chain case has reverse. Not sure if that makes a difference. Main drive shaft for the track had bearing changed on speedo side. Track was just aligned. Track is around 5/8 lug with v pattern studs. Suspension is an m10. Just rebuilt.
When I put the pipes in I put 153.8 jets and 2 q8 nozzles.
Never tried revving the engine with the belt off. I heard that's a bad thing to do and you could over rev the engine and blow it.
At this point I'm thinking it's clutches. I notice that the secondary shifts way too fast now and I'm always in overdrive. Revving too low. At 60 mi/h I'm revving at 6700. It's hard to get it to rev past 7500.
Anyone have some clutch specs for gyt pipes? How do I make the secondary not shift do fast and keep my revs up? Weights? Rivets?
When I put the pipes in I put 153.8 jets and 2 q8 nozzles.
Never tried revving the engine with the belt off. I heard that's a bad thing to do and you could over rev the engine and blow it.
At this point I'm thinking it's clutches. I notice that the secondary shifts way too fast now and I'm always in overdrive. Revving too low. At 60 mi/h I'm revving at 6700. It's hard to get it to rev past 7500.
Anyone have some clutch specs for gyt pipes? How do I make the secondary not shift do fast and keep my revs up? Weights? Rivets?
A couple of bucks
VIP Member
Hammer Down
Member
Try different belts. I've seen 500 rpm difference just from swapping belts. Also make sure the belt specs are correct, like v-belt over secondary, length and width.
Belt is brand new from Yamaha.
I've seen that chart before. I don't think it applies to my sled as I have a 94 and that's for a 96. Different clutches, and gearing says 21/35? That would make my machine bog even worse. That's more overdrive than I already have. And I don't see any specs for clutches like rivets, weights or springs.
I've seen that chart before. I don't think it applies to my sled as I have a 94 and that's for a 96. Different clutches, and gearing says 21/35? That would make my machine bog even worse. That's more overdrive than I already have. And I don't see any specs for clutches like rivets, weights or springs.
I get the feeling that's when I'm driving it's running rich, but not because it's jetted rich, because I'm feeding it a lot of throttle and it's just not accelerating good. Like its the clutches that are too far engaged. When I give it full throttle, it will shift out, but it takes a lot.
A secondary clutch that is acting up can certainly cause a sluggish running sled and low rpm and speed. Have you verified that the helix is the correct one for the sled/application. Any chance it was recut to a different angle years ago, probably very very slim, look for markings for the factory spec, and otherwise if it was recut. How old is the secondary spring, and is it the correct one also? They can look fine but still be sacked. Try a different twist angle. May be a good idea to just get a new spring to try.
Make sure the clutches are aligned to specs.
Lastly, get 'er swapped over to the 95-96 style, and start all over! lol, j/k but if you can get the parts, it would be a worthwile swap and you'd have parts more readily available for tuning. You'll have to verify if the reverse has any effect though. If it's in the chaincase you may be ok, if it's an add-on reverse you might have give it up.
Make sure the clutches are aligned to specs.
Lastly, get 'er swapped over to the 95-96 style, and start all over! lol, j/k but if you can get the parts, it would be a worthwile swap and you'd have parts more readily available for tuning. You'll have to verify if the reverse has any effect though. If it's in the chaincase you may be ok, if it's an add-on reverse you might have give it up.
The helix is the right one. No chance it was recut. Why does everyone prefer the 95-96 clutches for?
The reverse is stock, in the chaincase.
Looking for someone who has gyt pipes on a 94 600 and has clutch specs I can try.
The reverse is stock, in the chaincase.
Looking for someone who has gyt pipes on a 94 600 and has clutch specs I can try.
Aren't you basically asking a question to an answer you already posted? You brought this up in your first post...
If you look hard and long enough you'll probably find someone, they have to be out there somewhere.
That said, there are likely many, many more 95-96's out there with GYT twins and good clutch specs.