Main jet size for Tiger 885 motor

[Mike_PL]

is this the main jet you are talking about ???

please confirm, because I don't want to buy wrong ones.

...

[nightrunner]

Its been a few years since I've seen them.  Looks about right.   I removed one and took it to the shop so we could make sure I bought the same style.

[nightrunner]

I just bought a set of these from harbor freight $12.99 each.
Mounted them on a board.

http://www.harborfreight.com/cpi/ctaf/d ... mber=93547 (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93547)

I tried a set of vacuum gauges for syncing the carbs.  You'll need some sort of orifice (which could be as easy as pinching the tube) to dampen out the needle vibration.  I also found that the accuracy varied between the gauges.  That is they gave different readings when connected to  the same vacuum source.   I quickly sent them back and built a differential manometer.  There are posts on Advrider about how to do it.  Basically you need a long clear plastic tube and partially filled with oil or water.  Also need a valve or restrictor of some kind to dampen the vacuum pulses.    You hang the clear tube up to make a U shape and you will look for the difference in levels.   Also a good idea to have a chamber to catch the liquid so it does not accidentally get sucked into the port if one end comes off.  Each end of the tube will connect to the carb vacuum ports.  If the levels are at the same height, then those two carbs are in sync.   The device is much more accurate because it measures only the difference in vacuum as opposed to the total vacuum and then subtracting.

[ramseybella]

I assume you have mikunis and not Keihin carbs ..............

The mikunis for tigers are
105 main jets  
#40 pilot jets
and the needles should be in the middle clip with the pilot screw set at 1 1/2 turns to 2 turns out from seated

(mikunis are also noted for having the o rings leaking on the float assemblys which will cause rich running )

at 70 mph and above on a tiger with mikunis you are going to get average 30-35 mpg depending on how heavy your throttle hand is !

if you have keihins they came lean from the factory , like seriously lean

factory settings were
98 main jets
#40 pilot jets
non adjustable needles and the pilot screws were basically almost closed

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
big improvement

on either setup it assuming that only one snorkel is open on the airbox , there should be a blanking cap on the right hand snorkel.

if not it will be sucking too much air will need some serious increase in mains  and fuel mileage will suffer

the mikunis were gas hogs thats why triumph went to keihins on their carb'd bikes

keihins with the modified jetting will return average 35-40 mpg at 70 mph
at 50 mph they will give 55 mpg ................big difference , it's just the nature of the beast

What needles are we talking about shimming any photos of the needle?

[rf9rider]

The needles are number 7 in the diagram.

[Mustang]

YABBUT THATS A MIKUNI CARB .RAMSEY HAS kEIHINS
whoops cap lock sorry

https://www.bikebandit.com/assets/schem ... 6-2076.gif (https://www.bikebandit.com/assets/schematics/Triumph/TR-0606-2076.gif)
take a flat washer that is 1 mm thick by 8 mm diameter and has a hole of at least 3 mm ...slide it down the needle #4 in pic starting from the pointy end reassemble the slide .
This mod will fatten up the mid range nicely on a Keihin carbed tiger and eliminate the dead zone in the throttle between 4k and 5k

[rf9rider]

It was only for reference to show the needle.  :oops:

[ramseybella]

So Mustang these shims go before or after the VACUUM PISTON?
Reason I am asking I don't want to FUBAR it I just put the carbs all together and back on warmed it up and hook up the Motion Pro Sync, I was able to adjust a little but I was distracted buy my Wife (NO Way!!) and hit the gas a little to hard and sucked about 50% of the Blue fluid out of tube 1 and 2. So I am ordering another botel oof fluid a new OEM Air filter and will do this when I get all the stuff..

Thanks for all the Brain work you guys put into your replys!!

[fishnbiker]

I assume you have mikunis and not Keihin carbs
if you have keihins they came lean from the factory , like seriously lean

factory settings were
98 main jets
#40 pilot jets
non adjustable needles and the pilot screws were basically almost closed

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
big improvement



Any speculations on what jets to use on Keihins when I change the old Mikunis off my Felix? The Mikunis now have 105,000 on them, so getting very tired. Been running (for 9 years) #130 jets with stock needle at middle setting & K&N airbox allowing 55 sq inches of flow area as opposed to 49 from stock airbox. General talk around home suggests starting around jet size 112. Now Dyno'ed at 101 hp with 3 into 1 Girly header & GSXR Titanium can, but need more mpg for long distance gravel.

Thanks.

[Mustang]

Any speculations on what jets to use on Keihins when I change the old Mikunis off my Felix? The Mikunis now have 105,000 on them, so getting very tired. Been running (for 9 years) #130 jets with stock needle at middle setting & K&N airbox allowing 55 sq inches of flow area as opposed to 49 from stock airbox. General talk around home suggests starting around jet size 112. Now Dyno'ed at 101 hp with 3 into 1 Girly header & GSXR Titanium can, but need more mpg for long distance gravel.

Thanks.

With your mods 112's would be a good place to start ...............but I have found that the mikunis and keihins are usually pretty close to each other in what they prefer for main jet sizes .
So if you are running 130's now , you may find that the keihins will want bigger mains than 112's.
Now for the bad news ...when you start getting into the bigger mains on the keihins you turn them into gas guzzlers just like the mik's.

I have a 98 with keihins on it and it had the snorkel open on both sides and 112's in it when I got it from previous owner .......but had no other mods . It ran good but started hard , and was a thirsty little critter.

I have since capped the snorkel and gone to 105's and it starts much better and runs really good . The reason I went back to a more stock setup was to get some better gas mileage out of it . Hauling the sidecar around even with more normal setup I still only get 25 mpg out of it
with 112's and open airbox I was only seeing 22 mpg .

For the sidecar though I think I am going back to 100's for mains to get the gas mileage up a little more ................speed aint what you need on a hack .

my other steamer (a 98) runs really well on 105's with slightly modified exhaust and stock airbox .

[fishnbiker]

Any speculations on what jets to use on Keihins when I change the old Mikunis off my Felix? ...........

With your mods 112's would be a good place to start ...............but I have found that the mikunis and keihins are usually pretty close to each other in what they prefer for main jet sizes .
So if you are running 130's now , you may find that the keihins will want bigger mains than 112's.
Now for the bad news ...when you start getting into the bigger mains on the keihins you turn them into gas guzzlers just like the mik's.


So, now it seems to work out that it won't much matter which set of carbs I rebuild, other than I already know what i have with the Miku's. I have tried them with smaller jets & even 128's don't let it reach full rev potential with the K&N airflow. I could think about cutting back the airflow by downsizing the filter screen size (I did cut it back from 65 sq in. to make the unit fit in the first place). Maybe just carrying an extra gas can will be the way to go. Or, I lose all that wonderfull extra power, Boohoo.