No mid-range, secondary issue?

Exciter570

Exciter570

Member
Joined
Mar 1, 2004
Messages
364
Location
Sacramento/Buffalo
Hi all-

Have been out riding the last couple of days on my '95 600 which I just had the primary clutch rebuilt with stock weights, rollers, some new bushings, etc..and it's running pretty well except for around the mid-range..it will run down the trail at 30-35mph quite nicely, but if I give it a little more throttle to run at 40-45mph it will get there but then it shifts, rpms drop and won't hold steady at 40-45mph, just drops back down to the 30-35mph range. I can get it to hold steady at 50mph and above but that's too fast down the twisty trails for me..

Anyone have any insight as to what would cause this? The sled just turned 8000 miles, maybe some parts in the secondary are worn and causing this?

Thanks for any advice!
 
Also, it does sound like it is loading up when I'm at or near the 40mph mark but I did a plug check and things don't look overly rich..the nodes were dry and grayish/blackish in color for the right side plug and grayish/touch of brown in color for the clutch side plug, some oil around the threads on both plugs..
 
Chris Replace Spring In Your Secondary. Also, A Term '' Grey '' On A Spark Plug COULD Mean Jetting Is Close. Chocolate Brown Is Term You Need Here. 3:16 (yammie Tony)
 
Thanks, Tony...I'll order one up...I forget what the mains are in the sled, they may need to be dropped a size or two..but I do know the needles are dropped to the top clip position..this thing was always a pig in the mid-range, but it was running great a few seasons ago and I was seeing 13-14mpg now it's not the same in the mid and I'm seeing a consistent 11.5mpg which made me think that something was up with the secondary..might get some new shoes for the secondary as well..
 
Last edited:
CHRIS I STILL DON,T LIKE THE TERM '' GREY'' that means lean, dry, heat, all bad. TAKE THOSE NEEDLES AND PUT THEM BACK IN 3 LOCATION. THAT SLED COULD ALSO be LEAN IN MIDRANGE AND FUEL STARVED. 3:16 (yammie tony)
 
Just checked the mains..they are 156.3s, the GYT tuning sheet calls for 152.5's or at most 153.8's with the twin pipes in the elevation and temp range that is normal around here..I've been 3-4 sizes fat all along and compensating by having the needle dropped (which seemed to work)...Also checked the compression and it is good, 130-135psi on both sides..

Going to get some 152.5's mains in there, raise the needle, and replace the secondary spring..hopefully this will solve things..
 
I found in the past with my GYT piped 600 that the recommended needle settings were a touch lean and my sled would have a surging type feeling and when I moved the needles up(richer) one washer this made a ton of a difference and seemed to have power all over the place.

Now the scenario described above was 10-12 yrs ago before all of the palying with the fuels.

You MAY want to go one step richer with your mains to be safe with the crappy fuel of today... Just my $.02 worth
 
Last edited:
Thanks, as I looked back at the tuning sheet I referenced it's not clear what altitude the 152.5's are meant for...I think they're meant for 3500-7000ft.... so I'm going to start with a set of the 153.8's and see how they work.. http://www.totallyamaha.net/forums/a...achmentid=8562

I'm with ya on the gas today..luckily where I ride there are a few places that sell non-ethanol fuel so I always make sure to fill up at one of those places..
 
Well, I put the 153.8 mains in the sled and they really didn't seem to make any difference at all..sled still sucks in the mid-range.. burbles at 35-40mph, it is a bit on the warm side today, about 30 - 32 degrees..

RPMs are as follows:

WOT 7700
45mph 6300
35mph 5600
30mph 5400
25mph 4800

It's frustrating because the sled used to have a pretty good mid range..so I'm not sure what has happened and can't figure out if it's jetting or clutching related, I'm thinking clutching related since it used to be decent in the 30-50mph range..also, I noticed the idle rpms are very high..about 2600, adjusted with the idle adjuster but I couldn't get the idle to drop...it should be idling around 1500-1600..I'm not sure what's causing the idle to be so high..

Also, is it ok to do plug reads while the sled is on a stand in the garage? I'm worried about the sled being too lean now that the 153.8 mains are in and want to check the plugs..ok to just run it on the stand at various rpms and do a check that way?
 
What's the wrap on your secondary spring? Is it shifting at the same shift speed as beofre the rebuild? Watch your rpm's to see. If it began when you had your clutches rebuilt, there's the starting point.

Good Luck, John
 
I believe the secondary is at 40* of wrap..I think that's stock, I've never changed what it was set at from the factory...I think the secondary spring may be worn out and has lost some tensile strength which may be causing the sled not to hold proper rpms at certain speeds..I have to order a new secondary spring but in the mean time I have one of the same color that has about 6000 fewer miles on it that I will put on tomorrow and see if makes a difference...

I'm also ordering new needles and seats...at 8000+ miles, it may be a little bit of everything contributing to the poor mid-range...
 
Cleaned em at the beginning of January...put the lesser used secondary in it today, a PPP primary, lowered the weight in the clutch weights and adjusted the needles to the 2.5 position..sled was still fat around 30-35mph but it was running better than it has all season and it was 34* out today.

New needles and seats will go in in a couple weeks,..I've heard that when the seats go that excess fuel can be pumped up past the needles..so, maybe new needles and seats will help clean it up as well..can't hurt..

Also, I had a tech who has a lot of experience with these sleds ride it today as well and he suggested possibly putting in a slightly stiffer secondary spring because the stock green spring is a really soft spring and something a bit stiffer might work well..
 
Thanks Tony,..I'm going to order a couple different springs, a new green and something else...do you know what the next couple stiffer options are after green?
 
You must log in or register to reply here.


Back
Top