Author Topic: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER  (Read 543 times)

teezer250

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SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« on: May 07, 2018, 08:26:35 PM »
Went out on a 80 mile fast ride today and near the end,heading back towards home,the engine was struggling to tick over and was bogging down when setting off from traffic lights.It runs ok once past tickover at around 3000-4000 revs.
After getting home I stripped the carbs yet again and got them in the ultrasonic cleaner after only cleaning them a week ago and putting inline fuel filters on.

I noticed the trumpet in the airbox was slightly not sitting properly in the lid so I unscrewed the lid and fixed the trumpet into place.
I then noticed the original air filter with a large hole in it and upon removing the filter,the crumbling remains were in the bottom of the airbox and some around the support grid and near the inside of the rubber intake hoses.
I dare say some has been sucked into the carbs so that's why they were stripped yet again for cleaning out.Some may have got in the engine but i have looked at the reed inlets and there is no sign of any crumbling foam there.
Looks like 32 years has finally took it's toll on the air filter so have to get a new one now.

SeaR1ck

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #1 on: May 08, 2018, 11:45:30 PM »
Can only blame yourself still using the oem air filter they need to be swapped after so long.

teezer250

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #2 on: May 09, 2018, 02:03:47 PM »
Can only blame yourself still using the oem air filter they need to be swapped after so long.

Yes you're right,not realised how long since I last cleaned and re-oiled it,time flies.

I took out the inlet rubbers and reed valves and found traces of crumbled foam in them and also in the crankcase/crankshaft area so I poured some petrol in and turned the engine over a few times to flush out any foam particles to the bottom and soak them up with a rag after.
New air filter fitted and the bike is running fine now and ticking over as it should.

ybk

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #3 on: May 09, 2018, 09:17:56 PM »
Yeah the filters do that over time. They look fine but literally turn to dust the moment you touch them.

davewills4

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #4 on: May 09, 2018, 11:56:28 PM »
Hi teezer, where did you get your new air filter from as could do with replacing mine.

SeaR1ck

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #5 on: May 10, 2018, 12:01:55 AM »
I just buy the square foam from like uni and cut one to fit myself.

teezer250

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #6 on: May 10, 2018, 02:35:11 PM »
Hi teezer, where did you get your new air filter from as could do with replacing mine.
Hi Dave,
I got 2 genuine yamaha ones from Fowlers of bristol on their website,7.06 each +3.00 p&p.
They only had 3 in stock when I got mine so only 1 left.
https://www.fowlersparts.co.uk/

Go to the parts section and type in the part number: 1kt-14451-00 and it lists it for the r1-z zeal but not the 2ma/1kt but it is the correct part as I checked in my workshop manual and fitted it yesterday after slightly oiling it with 2t oil.

jcsnook

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #7 on: May 10, 2018, 10:35:02 PM »
I just went thru that.  My filters were not that old either...or at least I didn't think they were.
If your not mixing gas, your not hauling ass!

jcsnook

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #8 on: May 10, 2018, 10:35:40 PM »
I just buy the square foam from like uni and cut one to fit myself.

I like that idea!  Work well?
If your not mixing gas, your not hauling ass!

SeaR1ck

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #9 on: May 11, 2018, 01:01:43 AM »
Yes it works great did it on my rgv and a few other bikes. Just make sure you get a big enough one.

James P

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #10 on: May 11, 2018, 02:46:25 AM »
Yes it works great did it on my rgv and a few other bikes. Just make sure you get a big enough one.

I'm glad it worked for you, but it doesn't work for me. It is probably easier if the filter outline has nice smooth curves and large diameter corners. However, if it has tight corners and scallops for air box cover screws etc., I find it a nightmare to cut these correctly. Foam can't even be marked accurately, so some other way must be devised for obtaining the correct outline. I've tried making an accurate cardboard template, but it is difficult to keep the foam and template in the same relative positions during cutting. If the outline isn't cut very close to the original outline, there will be gaps around the edge, leading to unfiltered air getting in.

Another factor is the density of the foam. It may be OK buying a foam sheet from a maker of air filters (e.g. Uni), but whichever foam is bought, how does one know that the foam is the same density as used for the OEM filter? Any difference could cause rich or lean running - not a problem if you're willing to spend time jetting to suit, but hardly as quick and easy (and with a good result practically guaranteed) as fitting a new OEM filter.

I tried the cut-it-yourself method for my KR-1 because the filters were no longer available from Kawasaki, but found it such a hit-and-miss affair that I wouldn't recommend it. Thus, I would recommend that if the OEM filter is still available from the manufacturer at a reasonable price, buy it!

Regards,
James

SeaR1ck

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #11 on: May 11, 2018, 03:57:22 AM »
Then your just horrible at cutting it's not that hard just can't rush it. The uni foam is fine not enough difference in density to effect jetting.

James P

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #12 on: May 18, 2018, 01:18:57 PM »
Then your just horrible at cutting...

 :)) I must be!

evan_calgary

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Re: SLOW RUNNING PROBLEMS AND DISINTEGRATING AIR FILTER
« Reply #13 on: May 31, 2018, 04:22:32 AM »
Same deal with the foam on bottoms of old gas tanks.  Just crumbles into dust.  That is an annoying problem but just part of the fun on rebuilding older motorcycles as i'm sure you are well aware!  Will keep an eye on for that.  My most recent one came with no filter so cut one from a sheet of foam as well.  The TZR has a fairly easy shape to cut  but I suppose to each their own.