Triumphrat

fundyrider

Update, I've talked to the dealer that sold me the bike last fall and explained to them the situation, if it is gummed up carbs, they will fix it, no charge. I'll let y'all know what they find.

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"You gotta make the journey out and in" Mike Pinder

fundyrider

Carbs were clean but o rings were rotted, , this a commom problem? The bike is a '99.

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"You gotta make the journey out and in" Mike Pinder

mcG63

The o-rings either dry out or are affected by the fuel that has gone bad over time. Since I bought new float assemblies and synchronized the carbs I have had lots of power and no hard starts!! Hope everything worked out with the carb overhaul.
McG63

narrowminded

Since we're on this thread about fuel leaks., I have a question. I've noticed a slight gas odor. Is this normal?

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ervdrvr1

I get a slight fuel smell from mine from time to time also, mostly noticable in the garage out of the wind. I havn't found any leaks, so I'm assuming it's just vapours coming from the carb vents. My engine runs great and fuel milage is good(well, as good as can be expected), so I don't think it's a major concern.

Erv
Deep in the Heart of Texas!!

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"Life is tough, but it's tougher when your STUPID!" John Wayne

jmccarrell

Is the problem with the float assemblies specific to the Mikuni carbs? Or do folks see the problem with the Keihin's as well?
I am looking at a 96 900 that has flooded the cases with fuel.
I'm under the impression that the 96 900 has Keihin carbs (can't check right at the moment) and I see lots of refs to issues with the Mikuni carbs.
Have folks seen case flooding with the Keihin carbs too?

ervdrvr1

If I remember right, all the 1200's have Mikuni's and the early 900's had Keihin's and later switched to Mikuni's(or vice versa, I forget). I think both have had probs with floats sticking open, particularly if parked on the side stand. However, the BIG prob is not just a float sticking, it's the fuel tap sticking open or left on prime AND a float sticking open. There's not enough fuel in the fuel lines to fill the crankcase by itself. I've had the #1 carb float stick open a couple of times and leak a little fuel out the airbox when parked on the side stand, but never fillled the crankcase. I check the fuel tap on a regular basis to ensure it's not leaking. Float leaks can come from the float sticking open a little on the side stand, the float seat o-rings damaged, the float valve seals old(they get a little round groove in them from be seated for long periods of time). O-rings and float valve seal damage will usually result in a rich running engine due to fuel leaking past. Best thing to do is to inspect the fuel tap to ensure it's not leaking on a regular basis. When not riding for extended periods, park on the center stand and drain the carbs and leave the drains open. This way, if the fuel tap leaks, you'll get fuel all over the floor, but you won't get your crankcase filled possably causing a hydrolic lock bending/breaking a con rod, blown piston/head gasket, etc. Of course, you can replace the vacuum fuel tap with a manual one(ala Pingle)and then all you will have to worry about is remembering to turn it off.

Hope this helps.

Erv
Deep in the Heart of Texas!!

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"Life is tough, but it's tougher when your STUPID!" John Wayne

sailfish

My '98 Sprint 900 has Keihins. I'm not sure of the year that Triumph switched from Mikunis but I'm guessing that it's '97 or '98. From the reading that I've done on the Trophy and the T3 Sport Touring forums, it appears that the flooding from non-sealing float valves is exclusively a Mikuni problem (knock on wood). After 10-12 years of being bathed constantly in gasoline the o-rings give up. I don't remember the details of the Keihin float valves, it's been 2 years, but I don't recall any serviceable parts in them like o-rings so a leak would require a complete valve replacement.

jmccarrell

Ok, I checked and this '96 Trophy 900 has Mikuni carbs. And, as I live in California, it has all of the extra vent lines and carbon cannisters.

The crankcase was flooded with fuel after the bike sat for ~2 years or so.
When we tried to start it, the fuel / oil mixture pumped out through the crankcase vent hose into the bottom of the airbox and then on the ground.

So I take it the recommended advice is to:

• replace the float assemblies
• inspect the fuel shutoff valve for leaks
• or possibly replace the fuel valve with a Pingle fuel valve

• Do you guys have a known quality vendor for the Mikuni carb parts?
• Where can I find a description of how to check the fuel shutoff valve for leaks? The tank has 2 vacuum lines attached to it (thanks for the info so now I know what the heck those lines are!) which is more than this dirt bike owner is used to!
• Ok, so I found the Pingle fuel valves here. $75 per, but compared to gasoline in the crankcase, I guess it would be money well spent.
  They don't look like they have any vacuum lines on them, so I take it I just remove the vacuum line that goes to the stock petcock altogether and leave the other vacuum line on the bottom of the tank?

ervdrvr1

jmc,
Attached is the vacuum line routing for the Cali Evap system. You may not need to replace the floats, you'll have to pull the carbs and disassemble, clean, and inspect first. It's been sitting for 2 years, so this needs to be done anyways. Also, drain and change the oil and filter. Also, pull the spark plugs and pour appx 1 tablespoon of oil into each cylinder and turn over engine by hand to lube the cylinders/piston rings(fuel washes the oil away). To inspect the fuel tap, disconnect the fuel lines, NO fuel should come out the fuel tap on "run" or "res" with the engine off. Fuel should come out on "pri" only. Any fuel coming out on run or res means the diaphram valve in the fuel tap is stuck open and needs repairing/replacing. This is assuming that the fuel tab knob isn't broken and just spinning on the shaft. If not broken, pull the knob off and fill the voids on the back side with epoxy to prevent it from breaking. If it is broken, get an new one from Triumph(appx $9) and epoxy before installing. The Pingle fuel tap is a manual tap so no vacuum line is needed. If you go with a manual tap, just disconnect the vacuum line from the carb to the fuel tap and put a vacuum plug on the carb take-off port. This vacuum line is not connected to the evap system. Also, only one of the lines off the rear of the tank is a vacuum line, the other is just an overflow drain from the fuel cap(see attachment).

Hope this helps.

Erv
Deep in the Heart of Texas!!

Attached Images

900 Cali Evap.JPG (73.8 KB, 12 views)

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"Life is tough, but it's tougher when your STUPID!" John Wayne