V-Twin Forum banner
1 - 9 of 9 Posts

·
Premium Member
Joined
·
219 Posts
Discussion Starter · #1 · (Edited)
Many failed attempts at trying to search the threads here for the setup that i have.

I`m looking for a baseline to get me real close with the Mikuni HSR45 Jetting on my 95 build. Forget the dyno`s boyz., nobody here knows how to use them in my area. (So i only have you guyz to help me out here) They look at me funny when i ask them about AFR. That`ll tell right off the bat that you dont want them to touch your bike at all. I also asked them what gear will the bike be in when they do their pulls on the dyno.., they said and i quote... "ohhh you must be a newbie boy.., we always dyno in 5th gear" <---- Wrong answer from what i know about dynoing harley bikes.

I am also unsure of the elevation here in NY for jetting (600ft for the fingerlakes region area.?)

Here`s my email if anyone can help me:
[email protected]

Here`s what i have:
99 T/C DynaFXDX (95inch bigbore)
SE HTTC CNC Ported Heads
SE HTCC Forged pistons
SE Headgaskets (#16101-01)
SE Perfectfit Pushrods (#18400-03)
SE Intake #29635-99
Mikuni HSR45mm Carb
Andrews TW60A (chain drive)
DynaTek Ignition (set on 30b)
SE Tunable 2 into 1 (w/16 disc`s and enclosed end cover)

The jetting i`m looking for is: (Mikuni HSR45mm)
Which ---> Pilot - Main - Needle - Pump nozzle
& "E" clip position - Idle screw mixture turns from seated...???

Where are you guyz setting the accel pump to start moving..???
(i tried the 0.080thds..didnt work as well as 0.000 clearance`s did)

Any idea of rough torque & hp numbers with this type of build..???
(no dyno available here)

Thank you guyzzzz GREATLY., for any help you can offer.
(larry in NY)
 

·
Registered
Joined
·
365 Posts
45HSR
Pilot 20 although 25 is stock and works well with most
Main 170 although 175 is stock
Needle 98 for me most work well with stock #97.
accelerator pump 50 stock is 70
Read the tuning article in the Mikuni web site. It will tell you how to tune the Mikuni without using a Dyno like I did. Mine runs well and I still have the urge to put it on a dyno to see how I did. I let a knowledgeable friend ride it saying "it was close enough to be set up by the factory" i.e. set for a wide variety of temperatures. The closer you set it to maximum horsepower or the edge, the more you have to adjust it during cold/hot spells or changes in barometric temperatures.

joepenoso
 

·
Premium Member
Joined
·
219 Posts
Discussion Starter · #3 ·
HSR Mikuni 45mm Jetting - Thank You Joe..!

:thanks: Joe.., thanks a bunch my brother...!! That is exactly the same jetting combo i have installed. It seem to run really well with it that way. With one exception.... its winter time here in upstate NY.., and i was noticing the typical pop back thru the carb from being a little lean off the idle circut. I figured being as cold as it is right now.., thats what my problem was and why it was popping back during take off. Just wanted to make sure i was on the right track with my jetting for it. (first time using the 45mm)

Sure could use a good dyno tuner in this area
As for the dyno issues around here.., these guyz in my area arent even qualified to work on bicycle`s bro. My wife and i will never take our bikes to the dealer`s ever again. We`ve yet to come out of the dealers shops without issues where we had to go back to make them fix it right. One time my wife had to go back 15 times for the same problem on a brand new bike. We made them buy the bike back and went somewhere else.

I build alotta guyz engines around here.., and i have a fair amount of education in the wrench turning world. Many many satisfied bikers here.., after quite a few builds for them.

PS... to bad NY wont let me open a bike shop here - argggggggg

sorry..., didnt meen to ramble :yawn:
 

·
Registered
Joined
·
365 Posts
Larry:
I live across the Great Lake from you and a little popping when warming up and riding in the the winter time on a clear day is normal. I bet after Spring it goes away because you jetted it for summer riding. It is a carb after all and if jetted correctly carbs stumble when cold until the motor warms up. Every one is spoiled with perfect responce from thier fuel injection and forget carbs don't work right until warmed up, just like our cars in the not too distant past.

joepenoso
 

·
Premium Member
Joined
·
219 Posts
Discussion Starter · #5 ·
Mikuni 45

Hi Joe.., i totally agree with you 1,000 percent...!!!! It was around 40 degrees when i was tuning.., and yes.., i was jetting it for summertime use for sure. (couldnt see any reason to jet it for this colder weather and then have to do it again in the springtime - i`ll just leave it alone till spring - lol)
This was the first time i`ve ever delt with a 45mm carb. So i just wanted to touch base with someone like yourself that has had more experience with the HSR45 carbs. I`m sure it will be fine when the weather begins to warm back up for us.

I work on tons of CV40 & HSR42 carbs and i dont have any problem with tuning those in. Just wanting this 45 to be close when i get it out there in the springtime

Thanks again joe., for all your great input my friend...!!! :beer4u:
(larry)
 

·
Registered
Joined
·
136 Posts
Have had them for years. On all my HD’s

I am assuming you have somewhere between 10.2 to 10.5 compression with your set up.

Pilot- 25 min. Air screw 1 turn out. You could run a 20 or 22.5. However they will be a little lean during the colder months. Will help the bike to run a little cooler in the warm months.
Acc. Pump. I would go with a 60. Make sure you have a space about the thickness of a nickel between the acc lever and plunger rod.
Jet Needle. stay with the 97 needle thats in the carb. You can probably run the needle in clip position #3 but I believe the midrange throttle response will be better if the clip is in position #2. (second from top of needle)
Main Jet. 165-167.5. Dyno would probably show the 165 as best. But the Dyno will not take into account hills, wind etc.

Goos Luck
 

·
Premium Member
Joined
·
219 Posts
Discussion Starter · #8 ·
Mikuni 45 Jetting

kgoose said:
Have had them for years. On all my HD’s

I am assuming you have somewhere between 10.2 to 10.5 compression with your set up.

Pilot- 25 min. Air screw 1 turn out. You could run a 20 or 22.5. However they will be a little lean during the colder months. Will help the bike to run a little cooler in the warm months.
Acc. Pump. I would go with a 60. Make sure you have a space about the thickness of a nickel between the acc lever and plunger rod.
Jet Needle. stay with the 97 needle thats in the carb. You can probably run the needle in clip position #3 but I believe the midrange throttle response will be better if the clip is in position #2. (second from top of needle)
Main Jet. 165-167.5. Dyno would probably show the 165 as best. But the Dyno will not take into account hills, wind etc.

Goos Luck
Hello kgoose..,
yes i believe i`m at around 10.1 compression with this setup. As for the accel pump adjustment.., i tried it both ways., per mikuni adjustment.., (0.080thds) and i also tried it with the pump opening as soon as the throttle begins to open (zero clearance) and it drastically made an improvent. (i`d say it was lean condition off idle at that point) The bike runs a little bit better at this time in this colder air with the pump shootin sooner., and i`m sure i`ll have to back it off come warmer weather. Thanks so very very much kgoose for chimeing in and giving us your thoughts and ideas..!!!! I will try anyones ideas that will make this bike run better...!!!!

Keep it comin folks...!!!! Would love to hear EVERYONE`S input and things they`ve tried that works for them too...!!!! :chopper:

(larry)
 

·
Registered
Joined
·
365 Posts
Actually the stock 45 HSR comes with a 175 main. It will be too rich for most builds The main that works best on the dyno wont give you the best ET in the quarter mile. 99% of the time you have to go richer main jet to get a better ET. Assuming you've perfected launch,shifting, etc.

joepenoso
:rolleyes:
 
1 - 9 of 9 Posts
Top