Help Revisited and not the Beatles, keihins!!

[ramseybella]

Sorry long winded but I am Frustrated at 4:00 AM!!  :shock:

Well as you know I had the Tiger Purring after much helpful encouragement from you guys to check the valve clearance did it all up on the intakes cleaned the air filter new gas line and filters didn't need to get into the Carb's just cleaned the crud off the outsides.
 She fired right up and even the choke worked as new smooth responsive running normal, took it on that 280+ mile run like riding a cloud no problems.
It sat for a day took it for a short run 20 miles sweet and smooth..
Sat for two days fired it up no problem choke worked as it did when I first put it back together warmed it up and just shut it off.
Next day was going to take a ride my friend stops over How's it Running?  I say" like a new bike", flip the choke on fire it up to show what a great job I did and she stalls, Hmm? Fire it up again and same thing F*(&%*%&%!? :? .. turned it over with the choke pulled back a little and had to throttle it a little to keep it running warmed up and idled OK not super, sounded nothing like it should have took her out just felt the dullness right off, took it out yesterday wishful thinking still same choke issue same dullness.
This is not the same bike as the days before running rich again on the Keihins!!
What is up?

Just to let you know I did not check the carb Synchronization seemed to be running fine first few days.

[Mustang]

the bike has set for awhile ....other than the last 280 miles . you will have to bite the bullet and pull the carbs out and take them apart and give them a thourough cleaning , sounds like plugged pilot jets if it won't stay idling or needs throttle to keep running

check the fuel filter cone that is inside the pipe where the fuel line connects to carbs
take the main jets and pilot jets out and soak in gumout carb cleaner
this is important............ do it !
before you put the jets back in the carbs hold them up to a light source and make sure you can see thru the little hole that is in them

if the tamper proof covers are gone set the pilot air screws at 2 turns out from lightly seated

blow compressed air thru every little passageway you find on the carbs

take the petcock off the bottom of tank and see if you get water and crud
if you have water in the fuel tank you will need to run a small wire up the drain hole that is located on the right rear corner of the tank (your bike sits outside doesn't it )
unscrew the nipple and shove anything up there that will reach to the top of the tank , you may have to take the cap assembly off also

put everything back together and report back

what year is the bike and what is the make of the coils that are on it ?

[ramseybella]

Mustang,


1998 Origional Coils, clean wire ends, sits under a porch with a cover.

The funny thing is that I did clean the small filter before I
 Re-installed the carbs also installed fresh gas line and a new inline clear filter at the petcock I see no water or crud/dirt at bottom of filter.

One thing on my 161 mile (Yellow idiot Light) refill during my long ride I got gas at some no name gas station on the reservation but since then topped it with Shell High octane?
  I have been waiting on my Carb parts O rings for the floats they came in two days ago (Is that a hint??)..

Another thing I should clear is It idles fine around 1300 RPM once warmed up, it's when cold it wants' to run at 1000 and a little below where the choke was working all this at first when I put her back together, tweaking the choke I can get her to idle at 1500 RPM during first start up but I have to throttle it till i set the choke rite, full choke will flood and stall the motor.
Full choke did ramp it to 3000 RPM when I first put it back together and the next few days after that and I could adjust it to whatever RPM I wanted during warm-up, it was perfect.
I will keep you posted on what happens I only have a few hours a night to work on stuff..

Thanks Mustang
 8)

[Mustang]

Mustang,


1998 Origional Coils, clean wire ends, sits under a porch with a cover.

then they would be GILL coils and they are prone to failure , but we will ignore them for now

I have been waiting on my Carb parts O rings for the floats they came in two days ago (Is that a hint??)..

 :?:  :?:  :?:  :?:  :?:  :?:  :?: erm ........Keihins  don't have o rings on the floats only the mikunis do , the Keihins are a much simpler design ...........but they were also jetted and setup a lot leaner than the mikunis

Another thing I should clear is It idles fine around 1300 RPM once warmed up, it's when cold it wants' to run at 1000 and a little below

turn the idle up a little bit so that warm it idles around 1500 it will be happier ....trust me :D


 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 especially on cold starts
with jetting like this you should be off the choke pretty quick

the washers to shim the needles in a keihin are just flat washers 8mm diameter with a 3mm diameter hole in them bought at a hardware store . in inch size that is 5/16 ths x 3/16 ths use three that are the same thickness , 1 for each needle

[nightrunner]

Agree with most of what Mustang said.  My Keihins came with 38 pilots and I moved up to 40's.  This was the biggest improvement.   Recommend you get brass washers if you shim the needles as steel will rust.  McMaster Carr has them and I can get you the part number but not right this minute.   And my screws were 2.5 turns out from the factory.  Note that after 3 turns, there is no more change; that is the end of the range.  You can keep backing the screw out but after 3, there's no change.  If you change the pilots then set the screws at 1 to 1.5 turns.   With this setup I can run with or without the right side air plenum cap.  I leave it on most of the time, but can remove it at high altitude where the air is thinner.  

On the mains, mine were also 98 and I went to 102.  But the pilots and shims made the most benefit.  This is a very good lesson on how carbs work:

http://hondanighthawks.net/carb14.htm

The manual specifies 1% CO (carbon monoxide) for the US version and 2.5-4% for the UK at idle.  Idle should be about 1000 RPM.   When I did mine, I used a CO analyzer; since Triump gave is those convenient little sample ports on the pipes.  In stock trim the CO was at 0.1%!!!!  Yup, one tenth of what it should have been.  Have it set now at about 1.5%.

[Mustang]

Nightrunner

were you the original 1st owner on the tigger ?

I ask because I find it odd that it had #38 pilot jets with the air screws set at 2.5 turns

every Keihin carb I have seen and or rejetted from factory specs had #40 pilots and the pilot air screws basically screwed shut all the way
trophys , tigers , T birds etc etc ........every US model I have worked on

were there tamperproof covers over the pilot air screws when you re jetted it ?

[ramseybella]

Something I didn't know!! :roll:
My local guy after I bought the Float Bowl gaskets not O rings sorry, asked if my oil level was over filled?

Went back home and checked and Damn it was like 1/4 + qt over.
I took a baster bulb and sucked it out to the normal level and pulled the choke in and Bam!! Started right up no stalling and choke works again, what he told me if oil was over filled it will get sucked into the air filter box  from the case vent hose and into the carbs fowling the plugs and running like Poo!!

But now i have gaskets I will clean the suckers..

[Sin_Tiger]

Great news, now go cook a turkey with what you have in the baster bulb  :lol:

[Mustang]

But now i have gaskets I will clean the suckers..

I would ride it ...........my motto is "If it aint broke don't screw with it "

[ramseybella]

Did a 160 mile run yesterday afternoon after sucking the extra oil out ran much better turned the idle up to 1500 rpm.
 I still need to check the carb Vacuum Synchronization but all seems to be good not great, most likely still some oil in the air filter as I have been wiping the little black carbon splatters off the back of the tail pipes they seem to have gone away after last nights 25 mile ride.

By the time I get done I will be needing a new set of tires, chain and sprockets!! LoL!! :lol:

[coachgeo]

ahhhhh don't you love simple fixes....

Most of all..... don't ya love a mechanic that THINX!! Seems like he may have good understanding and diagnostic skills. He's a keeper.

[ramseybella]

ahhhhh don't you love simple fixes....

Most of all..... don't ya love a mechanic that THINX!! Seems like he may have good understanding and diagnostic skills. He's a keeper.

SMR Motor Sports Santa Fe, NM..
He is in to what he does, nice guy..

[NeilD]

...
I bought the Float Bowl gaskets.... ..

any idea what model Kehins you have/ are they the same as later T/Birds etc??  did you buy genuine gaskets or did you find an alternative?  just asking as I need to pull the floatbowls off my TBS carbs and would prefer to source the gaskets locally/cheaper..  

[Mustang]

they are rubber rings that fit into a molded groove in the float bowls and are totally reusable no need to replace................

[NeilD]

mine haven't been apart in the 4 years I've had it, and possibly never, so just thourght they might've gone hard.... Kawasaki ZRX1200 used CVK36's so I've ordered up 3 floatbowl seals 'just in case'..