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Discussion Starter #1
found a set of Keihins for my Trident 900. I presently have Mikunis on it. A prior owner removed the air box and rejetted the carbs. Would the swap over be worth it? What will I gain, or what will I sacrifice if I do it. My Mikunis are running fine and as stated have individual pod filters on already, and the Kehins are coming off of a Trophy that had K & N filters on them. Since the bike was running when they came off I assume the Kehins were rejetted and will bolt right up to my bike. Any suggestions or info would be appreciated.
 

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G'day,

I haven't experienced Mikuni's on a triple but I do believe the Keihin's will give better fuel economy at the very least. The Mikuni's seem to wear out the needle and seat too but that may be after a number of years service. Most people with Keihin's that previously had Mikuni's reckon that they are a big improvement.

I am interested in your pod set-up. Not many people have had success with the pods, it seems that the stock air box gives the best all round performance. Also, I have read that the pods have to be beaten into submission as they interfere with each other. Is that the case with yours? How is performance across the range? Finally, what exhaust are you running?

Cheers,

Roden
 

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Discussion Starter #3 (Edited)
I've only had the bike a few months, and the airbox was off the bike when I got it. It ran ok when I got it, but runs better now since I've gone thru it. When I got the bike the idle was a little erattic , the vacum line for the fuel tap was open, the plugs were old, filters needed cleaning, and the carbs were a bit out of sync. When I pulled the old plugs the wear on them appeared normal with no indication of fouling or anything. Now with the vacum straightened out, cabs synced, with new plugs, the idle has smoothed out and it seems to run ok. I would note that in syncing the carbs we had a tough time getting them to remain equal over the power range. As you increased throttle one cylinder (generally #1 seemed to pull more vacum) and one cylinder (generally #3) seemed to lag. We finally settled to have them balanced at idle and a little above 4k rpm. I don't have enough experience with the bike to comment on its performance, but it seems ok thru the power range with perhaps a slightly (if even existent) decrease in power between 4k and 5k rpm. Beyond that is seems very smooth. The bike is stock except for the airbox, and some micron pipes, but with the airbox gone and the pipes changed I'm sure that the Mikunis were re-jetted for those modifications, otherwise I doubt if it would still run. I haven't had a chance yet to get it to the dealer for really tuning the carbs on the dyno, but that's my intention. If I change over the carbs I will probably wait to do that with the new carbs on. Other than to satisfy my curiosity and see if the new ones actually increase power, there is no reason to spend the money on dyno time (until after I change the carbs). I'll know if performance is impacted, and mileage will be apparent.

I've searched thru the forum and it seems as if everyone who changed to Keihins got better mileage, and perceived better performance. IMO, my mileage in the mid 30's range seems low, but others with the same engine have said that's about normal. I don't intend to race around, just cruise and occasionally get my jollies by getting on the gas a little (part of the thrill of a bike) so I'm not looking for any dramatic increase in power. However, if I can get a small increase in power, same performance, and better gas mileage I would probably make the changeover......
 

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I think that you would like the Keihins. I'm not bashing Mikuni but the Keihins are better built and last longer. They also provide better fuel economy. The nicest feature of the Keihins is that the throttle slides run on rollers so there is no metal to metal wear on the slide or body (and subsequently the main jet/needle).

Depending on how you ride your fuel economy seems low. When touring, I get about 45 mpg at 70 mph. I typically lose 1 mpg for every mph I ride over that. On a really good back road romp I'll get 35-40. The best ever was 60 mph but that was a 1.5 gallon top-off after being stuck in national park traffic all afternoon.
 

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I used to average about 35-40 from my 900 Trident. My Super3 is better. A recent trip to N Wales worked out at 57mpg. More hp,more mpg? More efficiency I guess:confused: (Mikunis fitted)
 

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pods

G'day,

I haven't experienced Mikuni's on a triple but I do believe the Keihin's will give better fuel economy at the very least. The Mikuni's seem to wear out the needle and seat too but that may be after a number of years service. Most people with Keihin's that previously had Mikuni's reckon that they are a big improvement.

I am interested in your pod set-up. Not many people have had success with the pods, it seems that the stock air box gives the best all round performance. Also, I have read that the pods have to be beaten into submission as they interfere with each other. Is that the case with yours? How is performance across the range? Finally, what exhaust are you running?

Cheers,

Roden
i have pods on one of my super 111, they are part# ru-2780,, it took a little playing around with, and a dyno jet kit , to get all to work right with the scoripion street extream exhaust,, but all said in done it came out great,, but i would not recomend to someone who just wants to put pods on and go,, cause you wont go very far or fast, total cost of all parts were ,, 1000.00 for pipes. 120.00 for k&ns. and 175.00 for full jet kit,,, ..the cost was worth the great sound, and 10 bhp.. ,, it also took 2 trips to the dyno ,but that was freebie,,and this is with the miks.
 

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mikuni main and pilot jets

Hi guys, I see a couple of you are running pod filters with mikunis. Any idea what main and pilot jets you've got in there?
 

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Having a set of both with stock airboxes and three sets of T3 carbs lying around, I can share my personal experiences with the stock setups and one experience with dynojet kit on the Mikunis. The airbox is part of the overall equation - running with parts of it off and it generally runs like its missing a cylinder, when its on it acts as a resonator in the intake system.

1. Stock Mikunis: when set-up right and freshly rebuilt, the throttle response is excellent, and I expect this is because the plastic slides have less mass. This is my personal favorite right now. The slides and needles begin wearing from the get go, but when they are fresh, they work great. I ride a couple of FI bikes from time to time and the drivability of these Mikunis is better than the FI systems in my little test sample, especially off idle, imo. Replacing a worn-out slide is about $40 each, needles/needle jet $10-15 each.

2. Stock Keihins CVK: Somewhat slower throttle response, particularly off idle for me, better 30% better fuel mileage for some unknown reason. Reportedly wear better (I have not had them long enough to notice wear or not). If you have a Mikuni bike and switch to CVKs, I think you'll probably want a Keihin-series throttle cable to get the best fit and you'll need different airbox rubbers and clamps if you want to play with the stock airbox at all. Slides are metal, but I didn't see any "rollers" the last time I had them apart. Maybe that is for the FCRs.

3. Mikunis with the Dynojet 5102 kit - Dynojet needles, jets, needlejet, drilled slides per kit. Worst off-idle throttle response and low speed drivability, a bit flat response down low, responds (abrupt power transition) 3000-3500 rpm on up. Fuel mileage the worst of all. My least favorite as it needs to be caned all the time to stay in the power. I have had this set on both bikes and liked them on neither. I might have a different opinion if I only did track days or dyno runs with these.

Sorta depends what you want to do. For puttering around at reasonable and sane speeds with an occasional zoom, it is hard to fault the stock setup for drivability, ime. WOT/high performance is a different target. I personally spend much more time in the former (and a more useful setup form me) and only a little bit in the latter.

When you move to pods and start fiddling with jet kits, you are into the territory where you'll have to rely on the experience reports of others, good or bad, and the one-off set-ups that work best for them. Plenty of people report great results but I have no personal experience on pods, or dyno data for my three setups, but someone might have something on their personal pod setups.

The old hinkley faq might be worth reading also as it spend a lot of time on Mikuni tuning, and some discussion on (not) diddling with the stock airbox, and dyno results.

I'm with dphex - I think the Mikuni BST-36 vs. Keihin CVK is Triumph least-cost-provider decision as to who put the least expensive package together for the model year. Although I enjoy playing with the setups for now, I personally don't see a compelling reason to switch for the price involved. You can performance tune either quite a lot and wear items/replacement parts for either are readily available.

Now don't get the other guys started on the FCRs... :D Whole 'nother kettle of fish.
 
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