91 Yamaha Phazer II overshifting and shredding belts

phazerwayne

phazerwayne

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NW Ontario
Hey guys new to the forum. ive got a 91 phazer II. Ive just added a aaen exhaust carbon tech reeds and re jetted. Been having issues with it now. seems to me like the machine upshifts too fast. Machine takes off like a bat out of hell gets to the top end then bogs back down to 5000rpm. it will continue to do this if you slow down to a stop and take off again. Im running stock green-yellow primary and secondary springs and stock weights. Going to check all my motor mounts today and tear into my primary see if theres anything obviously worn or broken. Any help with the issues much appreciated. Also sorry if this is the wrong section for this topic, new to the whole forum thing.
 
I did have some issues before where it was hard on belts but never lacked the power in top end. My old track was pretty worn out and i figure thats why it was hard on belts. I changed my track, pipe, reeds and changed main jets to 145's waiting on a set of 150's but its been mild so I dont think it being lean is an issue. I have power throughtout the band. Very good low and mid top runs good for about 5 seconds then revs down, almost as if its trying to shift again. All stock clutching and im setup on C*2 in the secondary.
 
Need to check center to center distance on clutches, and clutch alignment.
Center of primary bolt to center of secondary bolt should be 268.5 mm.
Back of primary clutch should be aligned with secondary. Any of those two things that don’t jive will cause lots of problems with a belt.
 
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side to side alignment? Is that Adjusted at the secondary or with the motor mounts or both? anyone know off hand what the center to center distance should be on it?
 
Sounds good, if primary is not aligned with secondary, motor mounts should be loosend just enough to be able to shift motor, too loose makes it hard.
 
just checked center to center its up to spec by my hairy eye ball. all my motor mount seem good and solid and the primary appears to line up well with the secondary. just double checked the belt number and it was the proper belt as well. my button ramps are a bit worn just waiting on some new ones. thinking about slapping my other secondary from my other identical machine on and giving it a whirl. which clutch would affect the machine in the top end the most?
 
Primary will, check bushings on clutches to make sure there is no slop on the shaft. Springs not broke, ect. have you rejetted or reclutched for the pipe?
 
just got into my primary spring looks fine but gonna replace with known good one. all my flyweights and bushings look good no slop in rollers minimal side to side on weights.
 
Do you have the setup sheet from Aaen for the pipe?
What weights are you running, and what is recommended?
When putting a pipe on, you in theory, should have to add weight to be at the same rpm as before.
But, pipe may need to run at a higher rpm than stock.
You said you have a bog after it takes off well.
Sounds like the secondary is shifting out too quickly?
Maybe try going a little more on the wrap on secondary spring to slow the shift?
I am no clutching expert, maybe someone else can add some suggestions.
 
i got the pipe used, i was in touch with aaen tech on the phone for all the jetting kinda closed my ear off when he talked about clutching but i remember something about a silver spring. my local tech figures ill get away with running stock clutching. pulled my secondary all apart cleaned it up and put a different cover with a newer bushing in it put an old used belt on seems to work fine now but i dont have the best straight away to test it in my yard. Also changed the primary and secondary springs to other used ones i had around. hoping i got er beat now. Would like to know a bit about clutching them if anyone here has experience changing out the springs and weights. when you say a little more on the wrap you mean the adjustment with the secondary spring in different slots correct? im guessing more wrap would be more twist angle to line the helix in?
 
Yes, the tighter you wrap the spring, is slows down the shift from happening, keeping RPMs higher.
I will search and see if I can find any info on the pipe.
 
Did a search, consensus is 147.5 mains, 100 to 110 pilots.
Some people talk about switching the rubber plugs in the bottom of the carbs. Not sure what that does.
Looks like there are two plugs on each carb. Some guys switched the outside plug from one side to the other, center stays the same.
Someone also said a pink/pink/pink spring works well.
 
yes i knew about the 147.5 mains. having trouble getting 147.5s so opted for 150s. have a set of 145s in rn. didnt touch the pilot jet and it seems to idle well. Took it for a ride down the road and im pretty sure its running right again. most likely worn spring or dirty primary clutch. gonna see with a new belt. im topping out around 6500 rpm with the stock springs, i deffinetly feel like theres more to be had though. you say a pink primary and pink secondary would be the way to go? the charts say the pink secondarys a bit harder then the yel-green. cant find any info on the pink primary though. what benefits will stiffening them up bring??
 
Also never touched any of the rubber caps just adjusted the idle screw on top and changed the mains. starts and idles mint
 
90501-602J0-00 pink/pink/pink primary spring
Looks like it’s the stiffest of all those springs, used in the stock exciter 570’s.
Should bring your rpms up. You wanna be over 7000; more like 7200 from what I have read.
If your not running at that rpm, you are down on power big time, and that 150 main is probably a little too rich.
 
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ok i will try and source out 147.5 mains and look for the pnk pnk pnk spring. if i stiffen my wrap in the secondary will i get more rpm back at my top end?
 
In theory, yes. But, the secondary should be used to control the shift, not tune rpm.
You could try it and see what happens. You may gain some rpm, but not much.
 
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