keihin jets supply in UK

[tomski]

hi all, having trouble finding some 105 jets for my 98 steamer (keihins)...live in London and called a local triumph dealer (carl rosner) but no avail..does anyone have any suggestions?

[CoolHandLuke]

Yes, there is a nice chap on eBay who I bought my Keihin jets from:

http://myworld.ebay.co.uk/cyril.motorcyclemailparts

[CoolHandLuke]

http://cgi.ebay.co.uk/BRASS-MAIN-JETS-K ... 462wt_1568

Two things.

The centre carb should have a smaller jet size than the outer carbs.  This is because of the restricted flow to the centre carb (even with two ports open).  This is the same on all models except the Adventurer which has 98-98-98 (that I have discovered so far).

This is what Triumph had to say about it:

The centre cylinder for our older engines were designed for different fuelling, running at different temperatures compared to the outercylinders, hence the different jets.

This carries through to the pistons and liners which have different
tolerances depending on the cylinder.

[CoolHandLuke]

With the Keihin, I would change your main jets to 125-120-125 and open both ports.  This has been confirmed as a good solution on two bikes now.  It looks like a 3rd has gone with 125-122.5-125.

I fitted the carb from a Sprint onto mine which left the factory with 120-115-120.  The dyno centre said I should take it up 2 and get back to them.  This ties in with the Sprint forums where they also recommend rejetting from 120-115-120 to 125-120-125.  I have yet to get back the bike back on the dyno and check the results...

Every bike is different; different exhausts, different fuel, elevation etc.  125-120-125 is good place to start from with both ports open.

[tomski]

great info as always thanks chaps!...

bit confused now as what i've read in the other post about carbs is:

what works well with keihins is
105 main jets
shim the needles up with some washers that are .030-.050 of an inch thick
and set the pilot screws to around 2 turns out


So if I do 125-120-125 will I need not need to raise the needles? Also what do you mean by ports open?

[CoolHandLuke]

I wouldn't worry about shims for now.

Just go with with the 125-120-125 and open both sides of the air box.

For the pilot screws, set them about 2 1/2 turns out whilst the carbs off the bike - this will ensure it will start.

When you put the carbs back on, make sure you balance them first then adjust the pilot screws second.

To adjust the pilot screws, you will need a right angle screwdriver.  For each carb, turn the pilot screw back in until the engine sounds like it is about to conk out.  At this point, turn it back out until it is running smoothly again.  Do this for all three and you should have a good pilot setting.

[CoolHandLuke]

So if I do 125-120-125 will I need not need to raise the needles? Also what do you mean by ports open?

If your Keihin is a stock Tiger carb, can you let me know what the standard jetting is please?

When you take all the bits off, you will see the airbox that runs either side of the seat has a blanking plate on the one side.  When you change your jets to 125-120-125, don't put the blanking plate back on - and if possible, get yourself another snorkel and filter.

As for poor economy, I have been getting 50-55mpg from my bike and the guy who went to 125-122.5-125 has said he has been getting 15km per litre, which works out somewhere near 50mpg.

[tomski]

fantastic thanks very much once again!...yes one side on the filter was blanked off so will not put that back..incidently i'm running carbon pipes (quite loud) made by carbon can co (uk)....so quite a bit lighter than standard and seems a lot more 'open'

coz I want to take the tiger to australia (riding london-oz) the snorkel and air filter will defo help...is that a home job thing ie tape some foam/filter like material over the inlets or extend with some sort of rubber neck and filter over?

[CoolHandLuke]

Just had a look at the book.  The Keihin came with 98's as standard.  This is the same as the early Adventurer.

The parts you need are as follows:

[Mustang]

Stock 98 tigers with Keihin carbs were factory set as below and lean as hell
USA MODELS were as follows UK and other markets may or may not have been the same , I obviously only know the USA Models
.98 mains on all three cylinders
some had #40 pilots some had #39 pilots (not sure why maybe an EPA thing depending on region)
the mixture screws were sealed (when you unseal them you would find the screws set anywhere from 1/2 turn out to fully closed )
the correct way to set the screws is with an CO2 meter screwed in the bung holes of the header pipes , US models were set to 1% CO2 all others at 2-3%
and the needles were non adjustable .

[tomski]

didnt i just read a post with someone saying DO NOT go to 125s??? or am i seeing things lol...

[Mustang]

ya but then I went and reread your original posts and saw that you have something other than OEM pipes and mufflers .so it's trial and error for you until you find the right combo

the 125 , 122 , 125  mains were actually the stock set up for early speed trips , and were that size because of the cam profile more than the exhausts .
early model t309 and 409 engines were all the same only they  had different cams depending on what bike they were in

they were color coded green for tiggers and the other models had red , yellow , and blue coded  dont know what models had what color cam other than tigger and usa Daytonas had green cams

the color codes represented different grind profiles , you also need to have the right ignitor to match the cam

I can tell you that a tigger with mikunis and a sprint executive engine runs just fine on std. tigger 105 mains , which btw is what tiggers with mikunis came with stock .

[CoolHandLuke]

the 125 , 122 , 125 mains were actually the stock set up for early speed trips , and were that size because of the cam profile more than the exhausts .
early model t309 and 409 engines were all the same only they had different cams depending on what bike they were in they were color coded green for tiggers and the other models had red , yellow , and blue coded dont know what models had what color cam other than tigger and usa Daytonas had green cams

That is not entirely true.  Whilst I am not going to dispute the colouring, there were only ever 3 sets of cams for the early 3 cylinder models and one of those sets was for the Super III.

The cams from the Tiger were shared with the 85PS versions of the Trophy, Sprint, Trident and of course the Thunderbird Adventurer and Sport.

If you research this, you will see the Triumph Tiger inlet/exhaust cams (1140410/114030) are used on all California 85PS versions of the early Triumphs and the Thunderbird Adventurer/Sport.

The third set of cams, were used on all 95PS versions of the early Triumph motorcycles, including the Speed Triple and the Daytona.  The part numbers for these inlet/outlet cams are 1140260/1140270, if you want to verify that.


Valve Timings....


Trophy 900 (85 PS versions)
Trident 900 (85 PS versions)
Sprint 900 (85 PS versions)
Thunderbird Sport 900 (83 PS@8500rpm, 76.0Nm@6500rpm)
Thunderbird Adventurer 900 (83 PS@8000rpm, 82.0Nm@6000rpm)
Tiger 900 (85 PS@8000rpm, 82.0Nm@6000rpm)

Code Select Expand

 Inlet: open = 1 degrees BTDC, close = 30 degree ABDC, duration = 211 degrees
Exhaust: open = 28 degrees BBDC, close = 2 degrees ATDC, duration = 210 degrees

If you want to.  You can replace the cams with the 98PS versions and then you will also need to change the CDI.


Trophy 900 (98 PS@9000rpm, 83.0Nm@6500rpm)
Daytona 750, 900
Speed Triple 900 (99 PS@9000rpm, 80.0Nm@6750rpm)
Trident 750, 900
Sprint 900 (98 PS@9500rpm, 78.3Nm@6500)

Code Select Expand

 Inlet: open = 21 degrees BTDC, close = 50 degree ABDC, duration = 251 degrees
Exhaust: open = 51 degrees BBDC, close = 25 degrees ATDC, duration = 256 degrees

Don't ever replace your cams with those for the Super III.  The cam lift was so high, these were known for flicking the shims out of the buckets - lol.


Daytona Super 3 (114 PS@9500rpm, 81.4Nm@6000rpm)

Code Select Expand

 Inlet: open = 27 degrees BTDC, close = 55 degree ABDC, duration = 262 degrees
Exhaust: open = 54 degrees BBDC, close = 28 degrees ATDC, duration = 262 degrees


[/b]

[nightrunner]

I also have a 98 and have different opinions than above.  My stock jets were 98 and 38.  I went to 102 and 40, shimmed the needles 0.030" with brass washers, and set the screws about 1.5 turns out.  Stock pipes and air cleaner.  I can run with or without the cap on the right side.  The idea being at high altitudes I can remove the cap.  When I did this I had access to a CO analyzer so I could actually tune to factory specs.  I shot for 2% CO at idle which is low for the UK range.  The US spec is much lower, and my stock jetting was even lower than that.

The result on mine was easy starting, no more flat spots, and improved mileage.

One important point is that the main jet does not control the mixture until past 1/2 WOT (wide open throttle).  Unless you blast around at high RPM all the time, you will get more usable improvements from slow jet and needle shim.  I found this article on carb theory very helpful.  

 http://hondanighthawks.net/carb14.htm

Note that the slow jet forms a base line (Figure 7) that is present throughout the whole range.  The needle jet, jet needle, and main successively build on that.  So logically one would start with the slow jet and get the idle and low end tuned first.  Then work your way up to WOT.

My 0.02

[CoolHandLuke]

Fair comment nightrunner.

I would like to highlight that my settings are not based on opinion but on a dyno run with experienced tuners making the recommendations.

As I wrote at the top of this thread, every bike is different and what works for me may not work for someone else due to, as you have said, altitude and fuel, plus variations in exhausts, etc, etc.

You are running with stock exhausts whereas I am running with BOS which allow the engine to breath better, hence I am getting good power and good economy (see my other thread on the dyno run).