I've read here in a few posts about folks having problems with the DynoJet jet kit. I just put one in my V-Force last night and I'd thought I'd share my experience for those that are thinking about adding a kit to your V-Force but haven't done it yet.

If you've already done it, you can skip this long post.

First, this was the fifth quad I've put DynoJet kits in so I kind of knew what to expect. I took my time on this install because of the posts I've read where folks had kits that didn't perform well.

I first took off the seat, and plastic on top of the airbox. Then I removed the airbox lid, and the screws and bolts that hold the air box on top of the carbs. Then I removed the 4 hoses that connect to the bottom of the airbox. I noticed that the short center hose that connects right in the middle of the airbox was crimped at the lip. I've never had the airbox off so this must have been done on the assembly line. I made a mental note to make sure I put this back on correctly when done.

Then I took off the black pad trim on both sides to make it easier to take off the carb slide covers and to get to the float bowls on the other side. I also loosened the clamps that hold the carbs to the intake manifolds. This allowed me to pull the dual carb assembly out of the manifold and get more clearance to work.

One tip that seems to work on these carb screws, whether brass or the painted black ones. If they won't unscrew with reasonable force, put a philips head screwdriver in and give the screwdriver handle a solid tap with a hammer. One or two taps usually breaks the screw loose. And it will prevent stripping, especially on the brass screws.

I took the covers off of the vacuum slides first, being careful to hold the cover on until the last screw was removed. This prevents the slide spring from popping the cover off and losing the last screw or spring. Then carefully remove the rubber vacuum slide that holds the needle basket and needle. Remove the stock needle. Be gentle and clean.

Since I live at about 4700 ft. and ride anywhere from 5000-9000 ft., I used the needle settings for 3000-6000ft thinking I'll open the airbox up more if I'm way too rich. Better to be a little rich than lean. DynoJet recommends groove #4 for my elevation. There are 6 grooves on the needle. I double counted to make sure I was putting the E-clip on #4 and not #5. Then place two spacers on top of the E-clip. The next part is tricky.

To get the basket/needle assembly back in the vacuum slide correctly, place the basket on top of the needle (with two spacers on top of the E-clip). I put my finger over the hole in the bottom of the vacuum slide where the needle comes through. Then making sure the basket/needle/spacers slid through the hole as a single assembly, I put a little back pressure on the needle tip with my finger while sliding the assembly all the way into the vacuum slide. There are two holes in the bottom of the vacuum slide, one for the needle, and one that needs to remain unblocked. So after sliding the basket/needle assembly in, make sure that none of the basket fingers are blocking that hole. The next step is to get the vacuum slide back into the carb.

There's only one way the slide will go in. There's a small rubber tang on the vacuum slide that fits in a depression in the carb. The tang has a small metal tit (for lack of a better word) in it. Make sure this metal tit fits in the hole for it.

Then put the spring and cover on. Be careful here. The spring will go in and seem to seat properly so you can screw the cover back on. One sure way to make sure that the spring seated properly is to screw the cover on. Then with your finger move the slide up in the carb. It should slide smoothly, and the spring should return it to it's original position. If it slides but catches, or won't return, then the slide spring is not seated. I ended up having bends in both springs and had to redo both. This is an easy thing to overlook because it seems everything went in correctly.

Then on to the main jets on the other side of the carbs. This actually is pretty easy. Unscrew 4 brass screws on each float bowl and replace the main jet. Place a rag under the float bowls to catch the small amount of gas that leaks out. The main jet is the jet sticking the furthest out in the needle jet housing. Don't put the come hard on this when you're finished replacing the original and tighten it. But make sure it's snug.

Then when the float bowls are back on the carbs, adjust the idle mixture screws as recommended by DynoJet. Two turns out for my application.

Before I put the airbox and plastic back on I fired the bike up to see if I was going to have any trouble. Damn thing fired up on the second try. How about that. [img]i/expressions/face-icon-small-smile.gif[/img]

Then just re-assembly everything in reverse order.

I noticed a definte boost in low to mid-range and the bike actually started a little easier. So I'm a happy camper.

Hope this helps anybody thinking about adding a jet kit to their V-Force.
Mark

 

Mark,
Good post!

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Thats about how it went with mine. I am happy with the performance.

 

mark, do you have any other mods done to the air box????

let me tale you about my nightmare i am going through with my bike.

this is what i dit the other week, i think i now were i have went wrong.

i installed the dial-a-jets, the d-g snorkel, the carbon hood and the fst module all at the same time.
note: from now on i will install one thing at a time and se how it helps or hurts my performance.

ok this is what i think i messed up on, i cut the baffle out of the air box, i thiink this is what is causing my bike to dye when i give it throttle and when it gets going it pops bake when you let out of the gas.

i tried to find some pilot jets, but no one has them (yes i tried every were) and sudco told the bike was a emissions standard bike and they did not offer any larger pilot jets.

so now i have orderd some jet drill bits and will try to drill out some pilot jets, i 2 extr pairs to try and figure this out.

i have also orderd a new air box and if i need to i will star over again and not cut the baflle.

i think by cutting the baffle i screwed up the air flow with the fuel ratio.

if any one has any coments on what i could do or look for i would greatly apreciate.

tobad i just cant leave well enough alone, lol

 

Crashdog,
Here are a few things that might be the cause:
1. The bike is too lean for the dial-a-jets to compensate. I know Dial-A-Jet recommends you get the bike in a lean condition for their product, but you can get into a too lean condition. I have two Suzuki Vinsons. I installed a Dial-A-Jet on one of them. I drilled 6 1" holes in the air box lid and put in UniFilters. Then I went down 1 size on the main jet. Then I installed the Dial-A-Jet. I found that it runs good at the richest setting. I then tried taking off the snorkel on my Vinson and I got the same symptoms you described. The bike ran bad under load and stumbled something terrible, even with the Dial-A-Jet on the richest setting. When I put the snorkel back on, it ran fine. So I believe I'm right on the edge. I'm ok with that because I usually ride at elevations from 6000-10000 ft. and I live at around 4700 ft. When I take the snorkel off of my second Vinson, and go up 1 size in the main jet (without a Dial-A-Jet installed ) the other Vinson runs great.

2. Your idle mixture screws are set too lean. When you let off the throttle, the path most of the gas takes through the carb changes from the needle circuit to the idle circuit. As the engine slows, most of the gas fed to the engine comes from the idle circuit. If it's too lean, you'll get the backfiring.

3. The spring in the carb is kinked and the vacuum slide isn't closing all of the way. This lets too much air in the fuel/air mixture and causing the backfire. This happened on my V-Force after I installed the DynoJet kit. I mention this in my original post.


I wouldn't mess with your pilot jets. First I'd try to adjust the idle mixture screws out 1/4 turn and see if that helps. If that doesn't work, I'd try to go up a size on your mains. If that doesn't work, I'd remove the airbox and move the slides with your finger and make sure they slide smoothly up and the spring returns them to the fully closed position.

Good luck. I know this is frustrating.

Hope this helps.
Mark

 

thanks kevin for the reply, i had already got the extra pilot jets and bought the special drill bits so i could drill them out today, so i played with the pilot jetting and took off the dial a jets. i had to go back up on the mains
but she is running above par now, i will test all the performance this week and see how it starts and runs all week.
for now i am going to leave the dial a jets off. i am going to hatfield mccoy trails in 2 weeks and i have to know my machine is running great, it is priceless to have a good reliable running quad up there when you are miles away from tools and parts. i will play with the dial a jets again when i get back and have more time, i do thank making the pilot jets larger is going to help me.

thanks again for the reply.