Dynojet And Mikuni Jet Relative Sizes

[Byte]

I wanted to make a topic for others to easily find. It's something that needs to be searched for all the time.

Mikuni Dynojet
140 149.3
___ 150
142.5 152.0
145 154.7
___ 155
147.5 157.3
150 160
152.5 162.7
___ 165
155 165.3
157.5 168.0
___ 170
160 170.7
162.5 173.3
___ 175
165 176.0
167.5 178.7
___ 180
170 181.3
172.5 184.0
___ 185
175 186.7
177.5 189.3
___ 190
180 192.0
182.5 194.7
___ 195
185 197.3
187.5 200
190 202.7

[camaro1976]

i always had to search for it too. its bookmarked now! thanks

[cataway]

you mean this chart , i still question how accurate it is
Width------Keihin # -- DynoJet # -- Mikuni #
0.0350---- 92.5--------- 92----------- 86.3
0.0360---- 95----------- 94----------- 88.1
0.0370---- 97.5--------- 96----------- 90.0
0.0380---- 100---------- 98----------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4
0.0510---- 132.5------- 124--------- 116.3
0.0520---- 135--------- 126--------- 118.1
0.0530---- 137.5------- 128--------- 120.0
0.0540---- 140--------- 130--------- 121.9
0.0550---- 142.5------- 132--------- 123.8
0.0560---- 145--------- 134--------- 125.6
0.0570---- 147.5------- 136--------- 127.5
0.0580---- 150--------- 138--------- 129.4
0.0590---- 152.5------- 140--------- 131.3
0.0600---- 155--------- 142--------- 133.1
0.0610---- 157.5------- 144--------- 135.0
0.0620---- 160--------- 146--------- 136.9
0.0630---- 162.5------- 148--------- 138.8
0.0640---- 165--------- 150--------- 140.6
0.0650---- 167.5------- 152--------- 142.5
0.0660---- 170--------- 154--------- 144.4
0.0670---- 172.5------- 156--------- 146.3
0.0680---- 175--------- 158--------- 148.1
0.0690---- 177.5------- 160--------- 150.0
0.0700---- 180--------- 162--------- 151.9
0.0710---- 182.5------- 164--------- 153.8
0.0720---- 185--------- 166--------- 155.6
0.0730---- 187.5------- 168--------- 157.5
0.0740---- 190--------- 170--------- 159.4
0.0750---- 192.5------- 172--------- 161.3
0.0760---- 195--------- 174--------- 163.1
0.0770---- 197.5------- 176--------- 165.0
0.0780---- 200--------- 178--------- 166.9
0.0790---- 202.5------- 180--------- 168.8
0.0800---- 205--------- 182--------- 170.6
0.0810---- 207.5------- 184--------- 172.5
0.0820---- 210--------- 186--------- 174.4
0.0830---- 212.5------- 188--------- 176.3
0.0840---- 215--------- 190--------- 178.1
0.0850---- 217.5------- 192--------- 180.0
0.0860---- 220--------- 194--------- 181.9
0.0870---- 222.5------- 196--------- 183.7
0.0880---- 225--------- 198--------- 185.6
0.0890---- 227.5------- 200--------- 187.5

[Fakie]

its accurate. I can see a difference in hole sizes just with my naked eye (dj 155 vs mikuni 155).

[Byte]

Generic stating points for an HMF by year.

Z400: 2004 and Under
Slip-On System: 170 Mikuni Small

Z400: 2004 and Under
Full System: 175 Mikuni Small

Z400: 2005 and Up
Slip-On System: 145 Mikuni Small

Z400: 2005 and Up
Full System: 150 Mikuni Small

[CFM-Z440]

QUOTE (Byte @ Jan 13 2008, 03:47 PM)

Generic stating points for an HMF by year.

Z400: 2004 and Under
Slip-On System: 170 Mikuni Small

Z400: 2004 and Under
Full System: 175 Mikuni Small

Z400: 2005 and Up
Slip-On System: 145 Mikuni Small

Z400: 2005 and Up
Full System: 150 Mikuni Small[/b]

I would disregard those recomendations! They are using the stock needle which is not a good idea. Smaller jets would be used with either the alba or dynojet adjustable needle, and that would be much closer to proper jetting.

[NormalZ]

Most of the time, when you get a jet from a slip-on manufacturer, they're giving you a main jet only, and that main jet is way too large, overall. They're sending a main jet "too big" so the main will overcome the lack of midrange that the (non-adjustable) stock needle can't fix. It's a cheap fix for a huge jetting problem.

Just because a manufacturer sends you a 170 main for a slip-on pipe doesn't mean that's the main you need - that huge main will also flow more gas at midrange, taking up for the stock needle - but it's alot more main than you need for your 3/4 to WOT range. It's only a cheap compromise...

Best thing to do is get an adjustable needle if you plan to mod your motor - that's the foundation for all future motor mods. If you'll mod piece-at-a-time, get a DJ jet kit - it supports mods for a long, long time. If you mod everything all at once, buy a carb, too, and have it pre-jetted for all those mods. Save yourself the hassle.

[Byte]

QUOTE (CFM-Z440 @ Jan 14 2008, 12:07 AM)

I would disregard those recomendations! They are using the stock needle which is not a good idea. Smaller jets would be used with either the alba or dynojet adjustable needle, and that would be much closer to proper jetting.[/b]

Talk to HMF about it. I got it right off the website.

I use a DJ 165 and I'm changing it to a 160. I also added that it was a starting point.

[CFM-Z440]

QUOTE (Byte @ Jan 14 2008, 07:14 PM)

Talk to HMF about it. I got it right off the website.

I use a DJ 165 and I'm changing it to a 160. I also added that it was a starting point.[/b]

Man, when I still had a stock carb in my bike, even at a 440cc, high compression, and an open air cleaner, near sea level I never even got close to what they recomend. I think 165 mikuni was as big as it ever got.

But, like NormalZ and I both said, they are using the stock needle and that makes a big difference. That is a stupid way of doing it, but it makes it simple for people, who dont know what the hell they are doing, to jet their own quad.

It is by no means tuned well that way.

[camaro1976]

can this be pinned? i had it bookmarked on my laptop, but i had to search for it again on this computer.

[CFM-Z440]

2 years later is better than nothing right? STUCK