Steamer engine holds itself back

[ckarpurk]

Hello one and all, I am a new member (obviously) and have recently purchased a used steamer. It was quite a deal, the bike, corbin seat, original seat, service manual, and full 3-piece givi hard-bag set for around two grand. I have enjoyed looking through this forum over the last couple of days and have already read answers to many of the questions that have been ringing through my head.

This baby is a 1996 steamer with 80k miles (yes, 80000) on it. It was maintained very well by the fellow whom I bought it off of, and his father. Technically it is a one-owner bike, so I feel very lucky. The paint job is not standard, his father had it repainted a few years ago. There is an air box on it from a street triple I believe, hence why those little panels are not on it. The fellow who sold it to me had recently done a valve inspection himself. Also, he stated that he "never messed with the carbs..."

After I bought the bike, the first thing I did was look through the service manual and tear into the bike. All the fluids have been flushed and replaced, and tolerances have been dialed down to spec with the throttle. In addition, I also repaired the original digital clock which had been killed due to water-induced corrosion on the internal circuit board. (I also made sure to prevent this from happening in the future by drilling a small drain hole in the very bottom of the clock). On the whole I am very, very impressed with this bike. I can't wait to find some good crash bars so I can try this thing off-road.


The only "problem" I am having with the bike is that the engine seems to act as if its running out of fuel when I open up the throttle past the half-way point. It doesn't matter which gear I am in when it does this. Also if I open up the throttle fully open, the engine will accelerate "normally" as if there wasn't the "dead-zone" in the throttle range. Am I looking at a carb sync issue here? Or should I open up the cam cover and re-check those valves? I inspected the throttle cable, and it is due to be replaced (there's a small cut in  a part of it). However, it doesn't appear to be hanging and there is smooth throttle movement throughout the entire range or twist.

Looking forward to talking with you all.

[Mustang]

is the right hand snorkel on the airbox covered with a rubber cap ? if not it needs to be it sounds like she is getting too much air .

check that out and get back to us .

you may want to replace the airbox with the correct one for a tiger instead of a speed trip airbox , especially if the carbs are bone stock tiger carbs :shock:

[ckarpurk]

Originally that cap was on there, but I removed it because I figured it was left on by accident. Now it makes sense why it was on there.... I will put it back on and test ride it shortly, but are there some better needles I should get for the carbs anyway? Or would a carb service help in this regard?

*edit- how did you know to put it on the right side? That was the same side it was on originally.

[EvilBetty]

how did you know...?

 :lol:

Mustang is "The Man" when it comes to Tiger knowledge, ESPECIALLY steamers!

[aeronca]

mines on the left, but i got to be different :lol:   great looking bike, welcome aboard.

[nightrunner]

Yes, nice silver paint.  That's unique for a steamer.

You asked about needles.  There are threads here on rejetting the carbs.  Basically you go up one size on the mains and pilots, and you put shims under the needle clips to raise them up a wee bit.   It makes the beast start a lot easier in cold weather, improves mileage, and gives you more roll on power.   Most bikes are lean from the facory but the steamer seem to be extra lean.  

Congrats on the new kitty.  have fun.

[Mustang]

but are there some better needles I should get for the carbs anyway? Or would a carb service help in this regard?

believe it or not with the mikunis if things are left stock on the bike , they are set up very well as they came from the factory .

the 98 tigers with the Keihin carbs came very lean from the factory . Epa standards and also triumphs attempt at getting better fuel mileage out of the big pig .

if you ride the mikuni carbed tiger spirited and hard , your fuel mileage will generally suck . if you keep that tach in the 6 k range you will be down to 35mpg or worse

as mentioned in other posts the emulsion tubes or as bike bandit calls them 'needle jets'  go out of round with wear and it does effect performance.

but other than that the mikunis have a nice smooth bottom end and a midrange that pulls like a freight train ,
i personally wouldn't muck around with jets or needles on a mikuni carbed tiger .

now having said all that Dyno jet used to make a kit for the mikuni tigers, don't know if it's still available or not ..


edit**  Did a quick search and yes Dyno Jet does still supply a kit for 94-97 tigers with mikunis  It's pricey .........$126
http://www.dynojet.com/pdf/5103.pdf

[nightrunner]

Mine is the 98 with Kiehins so Mustang's advice on carbs is mo bettah.

I will add that you would benefit more (and for a lot less money) from going up one size on the pilots and raise the needles than wasting your money on a dynojet kit.  Dynojet kits focus on larger mains and proprietary needles, which will benefit you mainly at half to full throttle.

Here is a very good report on how carbs work.
http://hondanighthawks.net/carb14.htm (http://hondanighthawks.net/carb14.htm)

[ckarpurk]

Well Mr. Mustang you were right!

The bike is acting completely different now. What a difference a rubber cap makes! The bike now pulls like a John Deer in the mids, rather than slowing down... Hats off to you!

Nightrunner I am reading that report now, thanks for the info.

[Sin_Tiger]

This is just too weird :shock: , mine is almost exactly the same colour (still trying to get it resprayed) and has just a bit over 83,000 on the clock too.

The difference is this one is in Singapore, where are you?

I wish I could say mine hadn't been messed with  :roll:

[Colonel Nikolai]

Love the look of the silver tiger! Yeah, once I got the Mikuni's rebuilt on my 96 steamer, the bike was doing around 38 mpg. My 96 Sprint was getting 42 mpg when I first had the carbs done, now it's doing about the same as the Steamer. Both are mikunis. So in theory you _should_ be able to get 42 or so on them?

Someday I will learn how to tune carbs myself. Right now to me it's open heart surgery I want to leave to a qualified mechanic.

[Colonel Nikolai]

Tidbit on performance of these motors:

On my 96 Sprint I replaced the stock exhaust cans with a pair of straight microns and had the carbs tweaked. They weigh about 1/3 of the original and make the bike sound, well, mellifluous. There is nothing like the sound of the triple less restricted: makes my heart sing. Only the Ducati sounds as pretty (but totally different, natch).

The Microns added an amazing pull down low, but they cut down the top end: apparently the less restrictive cans mean the slides never raise quite as high  because they don't get the same amount of vacuum they used to. That's what the mechanic at Triumph told me. I noticed a slight fuel efficiency drop, too.