Hi all, I have had the 97 Tiger since February. When I went out to buy it, after a few minutes warm up with last seasons fuel, I took it down the road for a test. The PO had not bothered to add any stabilizer or keep the tank full, so when it hesitated at 2100rpm in 3rd, I just kept on going, eventually it straightened out. It was a bargaining point that allowed me to get the bike 400 cheaper, and had run great all through spring and summer.
In early September I jumped on to zip up the road for a small beer run, and noticed a "bog" and lack of power throttling up through second. Looked at the choke to make sure it was not on, check, so turned around and jumped on the Trophy instead. Last ride on the Tiger had been 3 weeks previous, a trip through the Trinity Alps with co-workers totaling about 250 miles, ran like a dream. So I thought maybe it was a fuel issue, added some Stabil, fired it up and let it idle a couple minutes, test run up the street, same thing.
Choke mechanism seems to be operating fine, (outside visual inspection), idle is steady, but when I crack the throttle I get the sense it's loaded up, and some popping/ backfire. So pulled the covers and tank, plugs are a bit black, like the mix is too rich (?). Changed plugs, but no difference. Fast forward a week, and more reading, I now have the breather box and carbs removed. I was going to pull out the filter and clean it, but there are two pair of #10 coarse thread screws on either side that won't seem to come out.
First question, how do the silly screws extract so I can clean the filter. And should I take a run at cleaning the carbs while they're off? I have read related postings where the thought was similar, " while the carbs are out, may as well clean them", followed by, " after reassembly it now runs worse than before" :icon_frown:.
PO had adjusted the valves, he has experience as a machinist so I feel they were done correctly. Rubber boots on both sides of the carbs are not cracked and seemed to be fitted well. All air box components are present and in the correct configuration, so my pea brain keeps coming back to carbs/ choke.
Thanks
Looks like you have the later (I think) air box with two M5 screws rather than one self tapper. You'll have to take the carbs off to get the air box out anyway so you might as well give them a one over at the same time.
The M5 screws go into brass captive inserts, so they have probably seized. Just pull them, then you can epoxy them back once you get them free.
Quote from: nucleardon on October 02, 2014, 08:03:13 PM
:blah :blah :blah Last ride on the Tiger had been 3 weeks previous, :blah :blah :blah..................
so my pea brain keeps coming back to carbs/ choke.
Thanks
3 weeks is enough time for things to go south with ethanol .
clean the carbs ...take them apart and clean 1 at a time , when you get everything all tidy put it back together , then do the next one , repeat for the third
nothing gets mixed up and if you get confused on reassembly you can still see how it goes together with one of the other carbs you haven't touched yet .
theres a sticky thread on how to clean the mikunis , they need it by the sounds of things
Quote from: Mustang on October 02, 2014, 08:55:04 PM
3 weeks is enough time for things to go south with ethanol
Yes; I speak from experience. Always stabilise the fuel if the bike is going to sit for any length of time.
Great, thanks for the input. Let you know how it goes. :icon_salut:
As Mustang said, clean the carbs thoroughly, pay special attention to the pilot screws, you need to use a strand of wire or similar to clean them out, don`t rely on just soaking them in cleaner or you`ll be chasing your tail.
Quote
clean the carbs ...take them apart and clean 1 at a time , when you get everything all tidy put it back together , then do the next one , repeat for the third
nothing gets mixed up and if you get confused on reassembly you can still see how it goes together with one of the other carbs you haven't touched yet .
Doing them 1 at a time is a great tip! Never thought of that.
Quote from: rf9rider on October 03, 2014, 02:37:19 AM
As Mustang said, clean the carbs thoroughly, pay special attention to the pilot screws, you need to use a strand of wire or similar to clean them out, don`t rely on just soaking them in cleaner or you`ll be chasing your tail.
Thanks, it's always the details that have you clinching in your sleep.
Soooo.... :icon_sad:, no joy on fixing the problem by cleaning the carbs. They did need cleaning, two of the three had jelled residue and clogged pilots, now they are clean as a whistle. I refitted the airbox with the K&N that was in the box of spares that came with the bike. The filter in the box, once I managed to split it open, was literally caked with a dirt and oil melange' and was beyond cleaning. I also refreshed the pre-filter on the open side of the intake as it had all but disintegrated.
Tank back on, battery with a fresh trickle charge, and it fires up and idles like before, making a slight adjustment of the idle screw to no doubt compensate for the work I had done. I slowly advance the throttle after letting her warm a bit, and can get her to high revs, but with some smoke issuing out both pipes, followed by popping that seems to be prominent from the right can.
Deeper issue? I have a new fondness for my Trophy and her trouble free three years of riding joy,(crap, I just jinxed my self). :icon_rolleyes:.
Just a small synopsis, ran great on a long day ride, parked three weeks, issue with poor running and power loss surfaces, addressed carbs, air box, new plugs, fresh fuel and stabil added at the fill.
Thanks for any suggestions on which direction to go next :wave
I have rebuilt the carbs on my Legend, which are Keihins, and then the Mikunis on my Tiger. All I can say is Mr. Mikuni's brother must have owned an o-ring factory, as these carbs take a bunch of different sizes and are much more fiddly to put back together.
My point is that doing a thorough cleaning and rebuild is not difficult, but it does take care and patience. It would be easy to forget something or clean everything. The float needle adjustment, for example, is fiddly.
If you are confident that you did everything perfectly, and all of the float heights were in spec, then here is where I would next look, keeping in mind the holy trinity (air, fuel and spark):
1- Fuel: upstream at the petcock filters (I assume you cleaned the duckbill filter in the fuel line?). You didn't pinch the fuel line when you installed it? This is easy to do.
2- Air: did a carb rubber get squished on either the intake manifold side or the air box side when you installed the air box? This is also easy to do. I run a stock air box myself, so I can't say if your K&N will mess up the air/fuel ratio enough to be an issue now that your carbs are adjusted correctly. Carbs out of synch can also make a bike run real ragged, and when you doing any work on the carbs, you should always re-synch after you are done.
3- Spark: not likely, but could coincidentally have started just as your fuel problem was addressed. Plugs, coils, wires, etc.
2-
I'm having exactly the same problem and have tried the same remedies with no result. I've also followed the advice on here and changed the jet size and put in the washers. To my ears it runs beautifully when idling or gently revving it up but when under load it bogs down.
Could it be the coils? If so how would I check. If not what? many thanks in anticipation.
i live up in newcastle you could wip up and ill stick 3 coils on for you to test it.could be the way to go or you may have a fuel blockage check filters in tank. :icon_salut:
Did you check and/or remove the filter in the T between the carbs?
When you say fresh fuel, was the tank actually empty? Check the petcock strainers inside the tank. My personal preference is to ditch the tank and carb filters to fit a line filter after the petcock, either a replaceable or cleanable one.
If you didn't use a decent balance tool is unlikely you will even be close, triples are not easy.
Quote from: Sin_Tiger on October 20, 2014, 06:47:13 PM
Did you check and/or remove the filter in the T between the carbs?
When you say fresh fuel, was the tank actually empty? Check the petcock strainers inside the tank. My personal preference is to ditch the tank and carb filters to fit a line filter after the petcock, either a replaceable or cleanable one.
If you didn't use a decent balance tool is unlikely you will even be close, triples are not easy.
:iagree
Thanks for the kind offer ynotbiker. I may take you up on that if i can't solve this. For now I'm going to check all the filters...anything but take the carbs out again...
Thanks all.
Here is my logic:
The issue with the bike is exactly the same as it was before. The cleaning and filter change, although necessary, made no difference either way, leading me to believe that I was on the wrong trail on my investigation. No problem, knowledge is gained with every experience.
The duckbill was cleaned, the external filter below the petcock was replaced, I did clamp the fuel line, but not the one between the filter and the carbs, because, of course the factory pet is not very good about actually stopping the fuel flow in the closed position.
Balancing the carbs is my next step, perhaps that was at issue from the start, I don't have triple gauges, or even three singles but will hit up a friend who builds customs and borrow .( As a Harley guy, he just gets a shy grin and sheepish manner when I start asking for opinions on my bikes). I will be reviewing the vacuum balance procedure from here and my Haynes.
The infamous coils....., since there was some mention of spark, and it is common knowledge that the coils have been problematic from that era, I plan to temporarily swap the coils from my perfectly running Trophy 900 as a test, once I confirm they are compatible.
If it turns out to be a coil, any suggestions on what to buy for replacement? And does it make sense to renew all three at the same time?
Thanks again, nic, sin and ssevy, :thumbsup
Definitely worth swapping coils. If itt is a coil,Pvl is your best bet(Nology use them). Use leads aswell. Worth checking crank pick-up gap? Is your airbox STD,good condition,and filter? Strange if bike was running OK previously?
Go on, take 'em out! I don't have a Steamer but I became adept at getting the carbs in and out on my mate's using Mustang's method and a couple of goes :thumbsup
Trophy 900 coils are same as s t Kramer
Steamer damn it, fuckin auto correct
Quote from: Mustang on October 23, 2014, 03:21:47 PM
Steamer damn it, fuckin auto correct
:ImaPoser Glad it's not just me.
Did you check the strainers INSIDE the tank? They are fixed to the petcock suction pipes, just remove the two screws holding the petcock to the tank, carefully! Oh and is a good idea to empty the petrol first :icon_redface:
Decided to put 3 new coils on as she's getting on. Runs like a dream. Thanks for support and really recommend the jet upgrade :icon_lol:
Happy Sunday to ya :wheel. Just an update on my power/ throttle up issues. I swapped the coils from my Trophy and no improvement, kinda figured but felt it was worth the half hour effort. I then proceeded to acquire three vacuum gauges, actually just picked up three fuel pump/ vacuum gauge kits from Harbor Freight for about $45, can see some other uses for them on my auto projects. Compared to a 4 gang set that is specific to motorcycle use, these did not have a damper so had to engage my high speed vision to average out the needle position as they did the flutter at idle.
Haynes recommends that you warm up the bike, then adjust the idle screw, which is connected to the #2 carb, to a spec idle of 1000 rpm, plus or minus 50. Once satisfied with the smooth idle, installed the gauges and compared the vacuum across all three, using #2 as the standard value. Now the manual indicates a certain range, 127-152 mmHg. Since the gauges were in Inches of Hg, I sort of punted and just adjusted to have all three gauges approximately equal, and the throttle response simultaneously good.
I'm happy to say the test ride went well, great response, smooth acceleration. Still concerned that the engine noise is greater than my Trophy, perhaps it is just the difference in the amount of faring on the bikes damping the sound on the Trophy, or perhaps I need Scotty to rebuild the warp engines :icon_rolleyes:.
Quick recap for those who may be traveling the same road with their Tiger: Sudden loss of acceleration/ throttle up after previously running well. Attention given to cleaning carbs, replacing spark plugs, replacing air filter, checking coils by swapping, emptying and cleaning out tank and fuel filters, ensuring the fuel line was not compromised, and finally syncing the carbs, which may have been the heart of the problem from the start. All items were necessary maintenance, and a good bonding experience with the old girl.
Thanks for all the input :wave.
Good for you. It's always satisfying when you solve an issue for yourself without having to resort to 'expert' (= expensive) help. And as you rightly say it is a good bonding experience.