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Discussion Starter · #1 ·
I am running the exact jetting that is pinned in the jetting section with no problems and am not planning on changing but I am a little confused about the Dynojet kit that is advertised. Looking at the main jets that come with their kit the largest main jet size is a 150 and the smallest is a 114. How is this supposed to give increases in HP by going a LOT smaller than even the stock jetting? Are their numbers correct or do they use a different sizing system for their jets and are actually bigger jets even though the numbers are smaller?
 

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They use a different sizing system. Don't buy one.
 

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Discussion Starter · #4 ·
I bought my jets 2 at a time at the dealer for about $3.30 a piece instead of the $40-$60 for a jet kit. The reason I asked about the dynojet kit was because I was looking at a DMC Alien exhaust and they recommend using the dynojet kit after installing the exhaust (the same company owns both products). If you don't go with the kit they recommend staying with the stock jetting which I know is wrong. Correct me if I'm wrong but any exhaust upgrade should equal a jetting change. Anyone have any experience with the DMC Alien?
 

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I got stuck with a dynojet kit from a company...tried it...and it blew!! It always had a lean spot on bottom. I guess I could have tried adding a pilot to the setup, but I was way too frustrated and confused with them. Plus, knowon uses them, so knowone on these forums can add jetting advice to your questions! I sent it back!
 

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Glad I ordered one! :| (dynojet kit) But I cant see it being that bad. I have one in my Raptor and put one in my friends 400EX and wolverine. No flat spots or troubles. I have a 45 pilot here and am adding that to the mix when I install my kit.
 

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I have one... I installed it last night. I put it in per the instructions for Stage 2 since I have airbox lid off, baffle out, and cam mod. I also picked up a 47 pilot jet because of some things I read about it not coming with a pilot jet. My dealer actually just gave me the jet.

I hope to ride it today and see where I am at.

The only problem I can see with it is that no one can relate to your numbers on here, so if you have trouble, help is a little harder to get. It's still just jetting though.
 

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I have the cam mod, stock baffel out, and air box mod. I put in the dyno jet jet kit yesterday. I went by the directions with the needle and mixture screw. As far as jetting I used the 150 main jet. The directions dosen't say anything about the cam mod or really specify on full exhaust or slip on, instead to use the recommended jet for either or on the exhaust. 142 is recomended with aftermarket full exhaust and or slip on and air box lid off. I figure with the cam mod changing the valve timing to make more power it also will need more fuel. I live in Iowa were the average temp is 35 right now and that the 150 main would work best and from riding now its a night and day differece. No dead spots. Even in 4th gear at a low rpm then laying into it no dead spots or surging from lean conditions. I've used dyno jet kits on my drag bike with no good tuning ability and went fi but there is no fi for the 450.
 

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well, I ended up putting in the 142... I have the same mods as you do, and sure enough, I checked my plug when I came home, and it was white. I just installed the 150, (which by my drill bit gauge seems only slightly larger than the stock jet) and it seems to stumble a bit when I give it gas. I'm going to mess with the airbleed screw a bit, but I have a feeling even the 150 jet they give you is too small. They say to give it 2.5 turns, so when I put in the 150 I only gave it 1.5. I didn't really give the motor a chance to warm up though, so we'll see.


I think I'm going to end up tossing this whole kit. I'll be at the Yamaha dealer on Tuesday picking up the correct jets.
 

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I let mine warm up good before I rode it being its cold here. I put the needle on the #5 clip and turned my mixture screw 2 turns not 2.5 like it says to. The thing starts right up with no problems and so far runs great. Now my air box mod dosen't have the whole lid off. I took the stock lid off and cut another hole just like the stock one by tracing and cutting a template and cut half off the down spout in the air box off and then used about 1/4 of an inch of it to make a lip so nothing can just fall in the box. I do alot of trail and creek riding right now since the hills are covered in snow and ice so I don't want to chance any water somehow finding it's way into my motor. I figure twice the the volume of air into the air box is better than nothing.
 

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well, I junked the DynoJet kit...

I kept the 47 pilot, installed a 170 main jet, #6 on the stock needle, and about 1.75 turns on the mixture. I let it warm up, and took it for a quick ride down the street, and it's quite a different bike. The term "raped ape" comes to mind. On it hard, I could barely keep the front end from lifting. It didn't do that with the DJ kit. Also, the jets are a LOT bigger than the DJ jets. Visibly larger.

I would definitely not recommend the DynoJet kit. Unfortunately, I didn't do much research before I ordered. Even when following their directions, the bike was still lean.

The actual parts I used only cost me ~$12. That's including 2 extra main jets. (172, 175. I live at 2200', but ride a lot elsewhere.)
 

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Originally posted by LateApex@Dec 15 2003, 06:10 PM
well, I junked the DynoJet kit...

I kept the 47 pilot, installed a 170 main jet, #6 on the stock needle, and about 1.75 turns on the mixture. I let it warm up, and took it for a quick ride down the street, and it's quite a different bike. The term "raped ape" comes to mind. On it hard, I could barely keep the front end from lifting. It didn't do that with the DJ kit. Also, the jets are a LOT bigger than the DJ jets. Visibly larger.

I would definitely not recommend the DynoJet kit. Unfortunately, I didn't do much research before I ordered. Even when following their directions, the bike was still lean.

The actual parts I used only cost me ~$12. That's including 2 extra main jets. (172, 175. I live at 2200', but ride a lot elsewhere.)
Good decision.
 

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Discussion Starter · #14 ·
It seems that all of the kits are a rip off (except JD). I did a lot of reading here and on the dadog page, spent about $12 on jets and my bike is dialed in perfect for my area instead of spending $50-$70 for some kit that will confuse me more than anything and is a waste of money. I probably owe JD and others more than the kit costs in the knowledge I gained from them.
 

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If I had to do it over I probably wouldn't have bought the dyno jet kit. On the same token the thing has no dead spots or falls on it's face anywhere in the rpm range. Header pipe dosen't glow red hot like it did when it came off the show floor. As for now I'm happy with it but when I get a full exhaust for it I'm sure I'll be calling dyno jet for bigger jets or tossing them and getting some from the local yamaha dealership. For the mods I have,cam mod, air box modded, and sparky removed with further mod to the stock can it runs damn good.
 
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