I'm helping a friend install his GYT-R aluminum slip on and GYT-R dual stage foam filter with billet adaptor and GYT-R needles. He is planning on running the lid off and will be primarily at 1000 feet with temps ranging from 50 to 80 degree.

Would really appreciate some jetting suggestions for those of you that know this engine well and that may have these or very similar mods done.

Thanks in advance for you recommendations.. I am hoping we can get the needle clip position, main, pilot and fuel mix screw close right off the bat.

 

I have the dynojet kit, same filter setup, and gytr slip on, lid on (wet and muddy out here).

I think it was 3rd clip, 146 left, 148 right (DJ), 2 1/2 turns on the left idle screw, 3 on the right.

I had to adjust my float level, to keep it from flooding out on inclines.

do a search,,,,take some notes,,,,,,install all the stuff,,,,and then start doing some plug reading to see where you are at (and make adjustments from there).

this topic has been beat to death

 

yah..did the search before posting and found 2 pages of post about jetting but nothing specific concerning the mikuni jets and the exact mods I am installing. However I've noticed almost 74 % of the posts made were with the dynojet kit.

so I'm going to have to punch it a few more times before the topic is completely dead..

thanks for your contribution however.

did you notice a significant difference with your mods? did you install different needles?

 

If you are staying with the stock needles then i would suggest 165, 170 mains, 25 pilots, and the needle in the fourth clip.

 

thanks Ernie.. but I think will slip in the GYT-R needles... any suggestions... maybe 3rd clip position?

 

That should be a good start for the elevation your at.

 

I agree and about 2 1/2 to 2 3/4 turns out on the mix. screws. And adjust your float level while your at it.

 

so this is what you guys suggest..

GYT-R needle set at 3rd clip from top
165/170 mains
25 pilots
2 1/2 to 2 3/4 turns on the mix


I don't have the shop manual, so can you let me know what the float is gapped at?

Also, what horsepower should this set up produce? 45?

 

Yes that's what I would try first.
HP would depend on what dyno you use, but 45 would be close.

This is the best way to adjust the floats.

The best thing to do is check it before you take it apart, with a piece of clear tubing. You can get the tubing at a hardware store for 20 cents, 1/8" clear tubing.

Thu September 05, 2002 3:11 AM



The quick & easy way to check float levels is to use a clear tube that fits the dump hole on the bottom of the carbs. You'll need about one foot of tubing. Don't worry about an exact fit, the tubing can be a little bigger which will cause some of the gas to leak out but gravity is forgiving and is constant! You can get the tubing from your Yamaha dealer for a few bucks also. Remove the stock dump hole tubing, put the new tubing on there & then bend up the other end and run it along side of the carb with the open end facing up. Then open the drain screw next to where the tube is connected & the level of gas in the tube should fill up & be level with or slightly above the bottom/top half of the carb's mating surface. If not, you'll need to adjust the float levels. A sign that the float levels are too high is if the stock drain tubes leak gas while your riding, you'll smell it for sure.
I just pop the carbs on the boots and set the tank on the frame and hook up the hose to check it again, you may have to take it back off once or twice to get it perfect. I also measure the amount that it is off and then take it apart, measure the float height and then bend the tab enough to raise or lower the float the amount that it was off. If that makes any sense.