Lag in 97

J

J bic

New member
Joined
Aug 20, 2013
Messages
18
Age
53
Location
Huntley, il
I bought a 97 last week and have done the following.


-drained the old gas and replaced with new good gas
- cleaned the carbs (143.8 mains, 47.5 pilots, and 1 1/2 turns out on screws )
-removed the tabs
-adjusted and tightened track
-checked the compression (120 on all 4)
-put in new plugs (1 and 2 looked real rich) they look fine now.


took it for a test run and had a lag off the start. Mid and high ran great.


took off the carbs and cleaned them again. Same thing.


am I missing something? About to loose my s#%t!


any help would be great.


thanks in advance!
 

Mine's a touch soft on the bottom too. It still spins the track anyway so I figure there isn't much point worrying about it. Can't use the power if I can't hook up.
 
If there are flat slides you may have to drop the needle down a washer or may be 2 they ran them a little rich on the needle from factory may be try that. It's a pain to do but worked great for me in the past
 
afew things on the vmax 4 would cause this.
1. engagement to low/ gased primary spring.
2. belt deflection
3. dirty carbs
4. need to increase pilot size
5. check secondary spring and twist
3:16 (yammie tony)
 
Last edited:
Turns out the sheave center to center distance and the offset were both off, as well as the belt being on the long end of tolerance.

Thanks for your help guys!
 
I wanted to ask your thoughts on belts. I ended up having better luck with a Dayco Untimax. It was an older belt too. Any thoughts on belts would be appreciated.
 
vmax4 came with a 89a-10 belt. in 1995 this belt was discontinued with a belt that actually worked better, and was slightly softer compound. the belt is the (yamaha) 8bu. i found it works the best on the vmax4. now with this posted i never tried a dayco, i found the yamaha belt works the best. 3:16 (yammie tony)
 
YAMMIEGOD3:16 said:
vmax4 came with a 89a-10 belt. in 1995 this belt was discontinued with a belt that actually worked better, and was slightly softer compound. the belt is the (yamaha) 8bu. i found it works the best on the vmax4. now with this posted i never tried a dayco, i found the yamaha belt works the best. 3:16 (yammie tony)
Click to expand...


I believe the Dayco runs 2mm shorter. Maybe that's why. I'm not sure why it made a difference from the 8bu since I set the center to center to spec.
 
2MM ALOT, AND IF NOT SQUEALING, I DOUBT THAT WOULD CAUSE A LAG OR SOFT SPOT IF IT WORKS. DO YOU LIKE YOU ENGAGEMENT THAT LOW ? 3:16 (yammie tony)
 
YAMMIEGOD3:16 said:
2MM ALOT, AND IF NOT SQUEALING, I DOUBT THAT WOULD CAUSE A LAG OR SOFT SPOT IF IT WORKS. DO YOU LIKE YOU ENGAGEMENT THAT LOW ? 3:16 (yammie tony)
Click to expand...

Now that I have the center to center in spec and the Dayco belt, its good. As far as the engagement, I haven't experienced anything else. I understand the 97 were clutched different.
 
if your clutching is set-up for a dayco and it works, its your call. i mysef rather see ya with yamaha belt. 1997 ,s were clutched different. 3:16 (yammie tony)
 
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