Changing Jets?

[yamaha1]

I am going to be heading to Wyoming in a couple of weeks so I will have to change my main jets. I am just wondering if anyone here has changed them before and could give some insight as to how to do it.

I am fairly mechanical but I thought I would see what people have to say so I don't miss something.

Can a guy do it without totally removing the carbs from the sled.. ie... take the air box off and undo three clamps at the motor then just tip them upwards to pull the bowls off.

Any other words of advise are welcome as well.

Y1

 

[pistons]

I tried what you said. But as I took the first screw loose from the float bowl, I thought, what the heck would I do if that screw fell to never never land in the bottom of the engine compartment? I took the time to completly remove the carb assembly. Don't forget to reconnect the oil hose to the bottom of the air box. I used needle nose vice grips to pinch off the coolent hoses going to the carbs.

 

[Bill Bo's Beauty]

I just got done doing this on a buddies sled, it's fairly easy just take off the few screws and tubes and while it's still connected tilt up towards the handlebars till you can see the caps for the main jets. Take some bunje cords and secure the carbs to the handlebars keeping them in place. then you are good to go.

 

[yamaha1]

Thanks guys for the responses.

Pistons- I have done just what you said many times working on sleds in the past. So if I ever do any work above the engine compartment I usually take an old blanket or big towel and drap it over everthing and try to work above that.

I was wondering more about the lengths of all of the tubes and cables and if everything is physically long enough to get them tipped up without unhooking everything.

By the sounds of what you guys are saying they are.

Thanks

Y1

 

[twomorestrokes]

The blanket tip is a good one. Dropping small pieces into this engine compartment is worse than the 2 strokes, and you may never see them again! (huh! wonder how I know that?)

These carbs are not hard to remove though. IMO it's worth it to get them on a bench where its easier to work. I take the throttle cable bracket off the carb wuth the cable attached to keep from having to readjust the cable and take the chance of a TORS issue.

 

[yamaha1]

I would normally take everything apart as well, usually go over everything. But since I am getting ready to head out west I will probably try to do it the quicker way, and then when I get back and have some time I will take it all apart to change it back to flatlander mode.

I like the blanket trick too......funny how you have to drop stuff down in there a few time and before you learn.

Y1

 

[Shivesy]

I just came back from the Continental Divide trails 2 weeks ago and had a great trip. I put on 700 miles which included crossing over into Idaho and heading up to West Yellowstone. I never touched the jets in the RS Venture and it ran perfect as far as I could tell.

 

[Bill Bo's Beauty]

What's the elevation range there?

 

[Shivesy]

I believe it is around 8000'-1000'.

 

[BigMac]

I just came back from the Continental Divide trails 2 weeks ago and had a great trip. I put on 700 miles which included crossing over into Idaho and heading up to West Yellowstone. I never touched the jets in the RS Venture and it ran perfect as far as I could tell.

I just got back from the same area ( West Yellowstone area altitude 6600 - 9200) and before going I re-jetted according to Yamaha's recommendations - main jet down to 145 (from 148). It ran fine.

Changing the main jets was simple - pull the airbox, loosen the carbs, lift he whole bank off as a unit without detaching anything. I hate the butter-soft screws Mikuni uses on all their carbs - the phillips recess gets buggered up easily. I always replace all of those screws with the black metric socketed hex-head screws so I can remove them with a hex wrench (Allen wrench). Any competent hardware store will carry them - the length is not very critical. Buy some extras - in which case dropping a few won't matter. It's also worth noting that they're easier to re-insert on the end of a ball-head hex wrench or driver than on the end of a non-metric Phillips head screwdriver.

 

[yamaha1]

Well, I got the sled all ready to head out west.

I changed the main jets, as stated above from 148 to 145, by taking the airbox off, loosening the clamps on the carbs and just tipping the whole bank of carbs up without unhooking anything. It went really well and I didn't drop anything into the engine compartment (covered everything up with a big towel).

Also changed the primary spring to a green-green-green and put in 8ES weights with no rivets (stock weights with rivets removed).

Should be ready to go!!!

Y1

 

[BigMac]

Well, I got the sled all ready to head out west.

I changed the main jets, as stated above from 148 to 145, by taking the airbox off, loosening the clamps on the carbs and just tipping the whole bank of carbs up without unhooking anything. It went really well and I didn't drop anything into the engine compartment (covered everything up with a big towel).

Also changed the primary spring to a green-green-green and put in 8ES weights with no rivets (stock weights with rivets removed).

I reclutched the primary for that area according to Yamaha's service manual - used an orange-silver-orange spring. It called for the same-as-stock 8ES weights, but different rivets. Since I put on about 500+ miles out there every year, I bought some weights and riveted them rather than re-riveting my existing weights every time.

I must say I wasn't too impressed with the clutching performance, although I suspect that was much more due to the secondary (which Yamaha said to leave stock) than engine or primary clutch. Top speed was 87 by GPS (96 on the speedo) across Hebgen Lake. Acceleration was mediocre IMHO.

 

[yamaha1]

Yeah, I just went by the information that I got from a friend of mine that I work with. He used to work for Yamaha snowmobile development and got me the specs from one of the test guys at Yamaha for what they tested.

The only thing I didn't do is the gearing, which I am not too worried about as all of us except one, that are going out there are first timers up in the mtns.

I figure we will be doing a lot of trail riding and some light off trail riding the first day. Then the second day maybe get out a little more. That way if someone breaks something while out exploring the deep snow (ie hits a rock) we don't blow the whole weekend.

I am not sure how the clutch tuning will turn out. I did like you said and just bought a set of standard 8ES weights without rivets and just changed them. That way I don't have to mess with the rivets. The specs I had said to use a green-green-green spring in the primary.

The one main difference is I have a Pioneer Performance roller bearing kit on my secondary with a 46 helix (I think). So we will see how that reacts out there. The roller bearing part should be great as it will give a little bit better response in backshift in the powder.

Only a week left until we go!!!!

Y1

 

[rage]

I bought the GRN-GRN-GRN spring last year for my 06 and took it along. I thought that would try it box stock to see if I had problems. Run great. I just got back from our trip this and again left it bone stock run just fine. Changing the weights and spring would have the R's up where they belong and changing jets may have increased my mileage (got 16mpg's +) a little bit but not worth the hassle.

 

[rx1mtn]

I do this trip at least 2 times a year. On the RS, I only wind the secondary an extra 10 degrees. This sled is the most forgiving for the mountains. I was very impressed. The RX1 on the other hand needs to have the 132.5 jets and the rivets removed from the primary. If you have never been to the mountains before the #1 advice I give to new commers is drink LOTS of water.