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Discussion Starter #1
Hi peoples,
I have a 1994 1200 daytona that wont accelerate above 5000 revs.
carbs been cleaned twice, feels like it gets a gut full of air and no fuel.
slowly opening throttle make a minor difference but still nothing overall.
I have to ride around at idle to approx 4500revs then shift gears.
112.5 main jet. needle has no adjustment just one groove on it.
thoughts???????
 

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Hi Sukzuki, I do my own valve adjustments and one time I got it wrong. I had one of the cam gears out by one tooth. The bike wouldn't rev past 7K. Another thing to check is the vacuum diaphragms. Look for rips or holes, or if it is twisted. Don't lose that little bitty o-ring under the vacuum cap.
 

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Discussion Starter #4
Yes, Header pipe temp good across all four after a 10 min ride around the streets, ( but cant get above 5000r)
And yes diaphragms good and that little oring was replaced under all four caps.
Bike barely gets above that first level after cold on temp gauge, does the ecu kill spark if mtr doesnt get warm enough?
 

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The next thing to check is the valve timing. You won't have to take the cover completely off, just loosen the bolts to lift it. Also take the right side crankshaft cover off. You'll need a 15/16 (24mm) wrench to turn the crank nut. When the crank is at T1 the arrows on the cam gear should be pointing at each other at the same level where the cam cover meets the head.
Newer bikes have ECU's and the computer controls almost everything, spark advance, fuel injection timing, throttle opening, etc.
Our bikes are old school. The CDI box controls the spark advance, and rpm rev limiter, and that's about it. The side stand switch will kill the spark but it has nothing to do with the engine warmth.
 

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If your valve timing checks out, you could have a defective CDI or ignitor that Greg mentioned. I had a 2001 SV650S that started to bog down under load as if only one cylinder was firing. Went through all the systems, carbs, electrical, etc until I finally gave up and tried a used ignitor. You can't really test those units. That was the issue. You have an old bike and these electronic components do fail at times due to heat or just age. Good luck.
 

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Discussion Starter #7
in regards to ignitor ? ( signal generator) on the side of the crank. That was replaced because was faulty, the second hand part i believe was off a trident of the same era. Guy at the wreckers said it checked out in regards to part numbers as triumph crossed over parts in that era.
my original didnt fire up the bike, i put new second hand on and presumed that part was ok. Did check ohms to it and it measured up ok. cranked the bike and started and ran.
Any chance that it is wrong or i have fitted it wrong? i think i was about .8mm clearence on it.
Checked Diaphrams against 2 sets of 90 gsxr750 kehin carbs and the 90s slides snaps back alot quicker than the trumpy carbs. Is that normal? almost feels the spring in trumpy has to overcome alot of vacuum.
Havent checked cam gear, that will be next.
 

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Discussion Starter #8
Ok, just a quickie, but fitted 125 mains and adjusted mixture screws 2 1/4 turns out. bike rode heaps nicer up to 5000 revs then started to break down again, no acceleration poor running above this.
Anyone here got jetting specs for theses carbs.
cam gear this week ;)
 

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The signal generator is not the ignitor or CDI. The ignitor is s somewhat larger black box with lots of wires going to it. Probably under the passenger seat or similar area. If the carb pistons are sticking or slow to respond, that would cause issues as well. Worn needles also.
 

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Discussion Starter #11
Does anyone know if 1200 trophy carbs are the same? as in diaphrams and slides, wondering if this would be a cheap option? obviously will be jetted to suit.??
 

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Hi Dan, Well that is a surprise. I was sure it was the valve timing. That would have been a cheap and easy fix. Now what? Carbs?
The 1200's used the same Mikuni carbs thru the model run. The 900's also used the Mikunis up until 1998-1999. Then they went to Keihin carbs. I had Keihin carbs on my 900 Trophy for about a year, too civilized. Even the 900 carb parts swap out with the 1200's, but the linkage is different. I don't understand why the main jets are so much bigger on the 900's. 125's compared to 110's. Probably it's a milder cam. How many miles do you you have on those 1200 carbs? If over 60,000 the needle jet tubes would no longer be round. But it wouldn't be the cause of the lack of revs. I think the problem is coming down to 2 causes. The vacuum slides aren't coming up, or you've got a bad CDI box.
I have two extra 1200 CDI boxes, but they are impossible to get to right now. They are in the shipping boxes that has been sent to Arizona. I'll be leaving California soon.
 

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Discussion Starter #13
Thanks to the response from everybody so far, really help full and narrowing it down.

Will concentrated on carbs at this stage because slides just don't feel right.
Will go to the wreckers and suss out if i can replace slides and the bodies they slide in, from some gsxr750/1100 carbs as i cant find daytona carbs over here.
Does anyone have jetting specs or a link of where to find what factory settings were?
bike does have 60,000kays so if factory will presume they are worn but want to make sure what goes back in is as per factory.
Cheers
 

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sukzuki - before you go to a lot of effort and assuming you haven't tried this already, I would open the gas cap and try getting it to rev above 5K. If the vent holes are partially clogged, it may not be flowing sufficient fuel. It is an easy test and simple fix if it solves your problem.
 

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Discussion Starter #16
ok Coraja will try what you said > thanks.
Carb slide and bodies are plastic Felony so no can do on that one.
Cheers peoples.
 

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Hi Dan, I'm still thinking about this one. I've got an air compressor and if I blow air at the air inlets above the Venturis the slides will come up. If you lift the slides up they come back down when released but they don't snap back down, they just gently come down. There are fuel vents on the top on the carbs. Usually there is a hose coming off each vent. I used T connectors and tied those fuel vents together into one vent hose. Are the vents clogged? The only other thing I can think of is the condition of the diaphragms.
My other thought is why does it top out at 5 grand no matter what gear it is in? Or am I incorrect on this point? If that is true it seems as if it is a CDI box problem. It wouldn't take much throttle to get past 5 grand in 1st gear. My 1200 Trident used to be a 1200 Trophy. It's the bike Triumph should have built. The CDI box is under the seat. For some weird reason I have 2 more CDI boxes, I don't know how I got them. I'm over 70 and my memory ain't what it used to be. To be honest it never was much good. Anyway, one of the boxes has the ears and it is mounted in the fairing behind the headlights. The other has no ears and is mounted under the seat. Does that mean it is for a Daytona? I don't know, maybe the single headlight Trophy in 1995. Would you be interested in one of the CDI boxes. Send me a private email.
Greg
 

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Discussion Starter #18
ok, been a while
went for a ride with open gas lid and made no difference.
went to the wreckers and got some diaphram slides out of similar carbs, fitted, slide up and down nicely, similar to all the other carbs i have in the shed and smother in operation than originals.
Made no difference to the ride though, basically at 5500 it starts breaking down and feels like it only runs on 2. thoughts? should i start considering electric side of things?
ive pulled needle jets out of carbs, there are no markings on it. Does anyone have carb jetting specs for these please?
 

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Hi Dan, It has got to electrical at this point. Main jets are big enough that they never clog up and besides the needle is going up & down thru it constantly. Will it rev up to 6 or 7 grand in neutral?
Can you borrow somebody's 1200 CDI box? A 900 CDI box won't work.
Greg
 

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Main jets are big enough that they never clog up and besides the needle is going up & down thru it constantly.
The needle does NOT go up and down through the main jet. And they are not 'big enough that they never clog up'.

Perhaps you meant to say needle jet (also called emulsion tube esp. if holes drilled along its length).
 
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