Dyno run

[jht]

took her finally in for dyno run at Big CC

printout should be attached

K+N, Laser Pro pipes, R1 fuel pump, 160 Mains (dynojet ones), Pilots 2 1/2 turns out, Stock needle setting, FP Emulsion tubes

Rich as f~~k and I'm still getting around 45-47.5 mpg

[attachment=o426]

This post was last modified: 11-05-2007, 08:20 PM by jht.

[jht]

Toying with jet sizes and came across this, posted several times on a few websites, anyone came across this before?

Gonna call PDQ to get their take on it in the week

http://faq.f650.com/FAQs/JetKitFAQ.htm

http://www.ds650.net/mikunivsdynojet.htm

http://www.angelfire.com/pa5/cannondale/Mi...vs.dynojet.html


Ever wonder why mikuni and Dynojet Jets have different numbers for the same amount of flow? If yes, then read on to find out why.

Mikuni Dynojet - Main Fuel, Primary and Secondary Pilot Air Jets

Flow rates based on size markings of Mikuni and DynoJet jets are not comparable. As a guide the chart to the left indicates equivalent sizes based on the diameter of hole in the jet.

Mikuni jets are chamfered on the inside opening at the threaded end and Dynojets have a machined flat surface. Keep this in mind when using this chart. These physical differences will never allow an exact comparison.

This chart is intended to be used as a tool to assist you in making a more accurate decision when selecting a jet size range or comparing tuning data where an opposing brand is being used.

Actual jet sizes are highlighted.

DynoJet jets are marked according to the diameter of the hole in the jet .. ie: DJ150 = 1.5mm and DJ175 = 1.75mm.

This is not true for Mikuni or most other OEM equivalent jets. This size Mikuni jet, (N102.221 Super BN), is marked according to its' flow rate, ie: 150 = a rating of 150 cc of fuel per minute.
--------------------------------------------------------------------------------

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

(copy + pasted info, tried to seperate table above so easier to read, but in aint working..)

This post was last modified: 13-05-2007, 10:26 AM by jht.

[Guest]

<!--quoteo(post=40472:date=Sun 13th May 2007, 11:07 AM:name=jht)-->QUOTE(jht @ Sun 13th May 2007, 11:07 AM) <{POST_SNAPBACK}><!--quotec-->Toying with jet sizes and came across this, posted several times on a few websites, anyone came across this before?

Gonna call PDQ to get their take on it in the week

http://faq.f650.com/FAQs/JetKitFAQ.htm

http://www.ds650.net/mikunivsdynojet.htm

http://www.angelfire.com/pa5/cannondale/Mi...vs.dynojet.html


Ever wonder why mikuni and Dynojet Jets have different numbers for the same amount of flow? If yes, then read on to find out why.

Mikuni Dynojet - Main Fuel, Primary and Secondary Pilot Air Jets

Flow rates based on size markings of Mikuni and DynoJet jets are not comparable. As a guide the chart to the left indicates equivalent sizes based on the diameter of hole in the jet.

Mikuni jets are chamfered on the inside opening at the threaded end and Dynojets have a machined flat surface. Keep this in mind when using this chart. These physical differences will never allow an exact comparison.

This chart is intended to be used as a tool to assist you in making a more accurate decision when selecting a jet size range or comparing tuning data where an opposing brand is being used.

Actual jet sizes are highlighted.

DynoJet jets are marked according to the diameter of the hole in the jet .. ie: DJ150 = 1.5mm and DJ175 = 1.75mm.

This is not true for Mikuni or most other OEM equivalent jets. This size Mikuni jet, (N102.221 Super BN), is marked according to its' flow rate, ie: 150 = a rating of 150 cc of fuel per minute.
--------------------------------------------------------------------------------

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

(copy + pasted info, tried to seperate table above so easier to read, but in aint working..)<!--QuoteEnd--><!--QuoteEEnd-->


not strictly true
there are two types of mikuni jets - hex head and screwdriver slot

the ones with a screwdriver slot are numbered in the dia of the hole, the hex main jets are flow rate.

It has been proven on Thmpetalk that Mikuni and DJ jets are the same.
Do not believe what DJ tell you - they are in the market to make money from selling their jets.

[TonyDevil]

been messing around with carb tuning and couldnt find this info anywhere
was down at PDQ today and they did a photo copy for me [img]style_emoticons/<#EMO_DIR#>/good.gif[/img]




and then JHT taught me how to balance carbs [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]
they werent great, but sorted now [img]style_emoticons/<#EMO_DIR#>/yahoo.gif[/img]

[chill]

I final had a dino check done on mine today.
model 2002 with 60000 km, only done the air box mod and running a 170x60 rear tyre.
One up I average 22/23 km/lt (on a quiet run up to 25). Two up and loaded 19/20

When I can figure how to add picture I will but for now.

Figures are Hp = 71.72
Torque = 56.13

[jht]

Recent run as need to get arond to leaning of the top end (only 5 years later!)

Used Dyntoech over near Tadley, nice bunch of bloke who definitely knew their onions

Since 1st run back in 2007, have had top end rebuild with relapped valves & new stem seals, honed bore & rings (all about 6-8k miles ago)

76.93bhp, 61.4 ft/lb torque

This post was last modified: 23-06-2012, 10:33 AM by jht.

[Studley Ramrod]

That's healthy ! [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

Do you think it's the pro stocks that are leaning out the top end ? [img]style_emoticons/<#EMO_DIR#>/unsure.gif[/img]

[jht]

She ain't lean at the top Studders, she be tad rich [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img]
13:1 is kinda optimal A/F ratio, from 5k up she gets progressively richer
The lean dip around 3-4k is on the needle & more likely than not leaning out for emissions/noise test

[Studley Ramrod]

Hahaaa ! yes, cough cough ! Of course I knew that, errrr, just testing you bod ! [img]style_emoticons/<#EMO_DIR#>/blush.gif[/img]

[jht]

S'all right, yesterday I had a serious brain fart discussing the jetting and told Saga optimal A/F was around 11:1
[img]style_emoticons/<#EMO_DIR#>/rolleyes.gif[/img]

[Rallyist]

<!--quoteo(post=245955:date=Sat 23rd Jun 2012, 06:13 PM:name=jht)-->QUOTE(jht @ Sat 23rd Jun 2012, 06:13 PM) <{POST_SNAPBACK}><!--quotec-->She ain't lean at the top Studders, she be tad rich [img]style_emoticons/<#EMO_DIR#>/tongue.gif[/img]
13:1 is kinda optimal A/F ratio, from 5k up she gets progressively richer
The lean dip around 3-4k is on the needle & more likely than not leaning out for emissions/noise test<!--QuoteEnd--><!--QuoteEEnd-->


Could probably go down 1 size on main jet then run again as it looks like slide/needle may need fine tuning.

[palexxxx]

Correct air/fuel ratio is 14.7 (or so I'm told).

[dandywarhol]

14.7 by weight, around 30,000:1 by volume.

 

That graph fuelling looks ok to me for a full throttle application

[zeevgutkin]

Hi,

This is all very interesting.

I was wondering (and this may sound stupid...), do you have any experience with fitting a post 1999 carb (4TX4 40) onto a TDM 900 motor?

I'm asking because I've got the 900 motor fitted on my XTZ frame and the post 1999 carbs.

I get backfires from the exhaust when decelerating from high revs (>4000) at around 3000 - 3500.

I read somewhere that these backfires from the exhaust are a result of the mixture being to lean to fire in the cylinder and get ignited in the exhaust by the hot gases from a following stroke that does ignite.

In did when I pull the choke while decelerating from high revs, there are no backfires.

So far I've replaced the pilot air gets (2 of them on this carbs). The 120 is now 105 and the 87.5 is now 45 - yes it's better now, but I still have the occasional explosion at the rear end.

Any advice will be highly appreciated. 

Thanks.

Zeev.

[palexxxx]

Why would you fit carbs to an engine that has fuel injection on it as standard?  Seems to me like you want to go backwards in time.  Perhaps going from the Intercity 125 (or whatever the modern equivelant is (I haven't been in England in a long,  long time))  to going to steam.

[dapleb]

Things loike wiring and not getting your necked snapped off with terrible jerky/lumpyness in throttle response?  Carb for me anytime ta.

 

Zeev, I vaguely remember a post on ear of someone who put carbs on their 900 but dont have linky dink... EDIT: do have linky dink: http://www.carpe-tdm.net/ipb/index.php?s...nda&page=5

This post was last modified: 06-03-2014, 01:51 PM by dapleb.

[wicklamulla]

It'd be too much messing around with the efi to get it to run properly on an old super tenere.    carbs are the way forward!

[Studley Ramrod]

Also less electrickery to go tits up when you use carbs.

 

Regarding the backfire, both my mk1 and mk2a kind of backfired when decellerating and I'm wondering if you're actually getting a proper backfire as in an almighty bang, or just the smaller more frequent farty ones like my bikes did.

 

I believe the air cutoff valves on the carbs are there to help stop backfiring so maybe have a look to see if they're damaged/perforated ?

 

The 3-4000rpm range generally concerns the emulsion tubes and needle height.

 

I dunno if this CV Carb tuning guide might help you.  http://www.factorypro.com/tech/tech_tuni...gines.html

[marko67]

Also less electrickery to go tits up when you use carbs.

 

Regarding the backfire, both my mk1 and mk2a kind of backfired when decellerating and I'm wondering if you're actually getting a proper backfire as in an almighty bang, or just the smaller more frequent farty ones like my bikes did.

 

I believe the air cutoff valves on the carbs are there to help stop backfiring so maybe have a look to see if they're damaged/perforated ?

 

The 3-4000rpm range generally concerns the emulsion tubes and needle height.

 

I dunno if this CV Carb tuning guide might help you.  http://www.factorypro.com/tech/tech_tuni...gines.html

Hmmm, mine has started nasty botty burps on occasion when I come back to idle after currying it. Fresh mulching tubes about 10'000k ago sorted the last bout of biliousness. Will add that cut off valve to the check list of things when it goes in for a top end service. Ta Studley.

The bike has pretty much open pipes which I'm sure exacerbate any carb issues.