Anyone fitted a fuel filter to a 1991 CBR1000FM?
#13
Something sticking now???
The fuel filter is fitted and seems to be working well (at least for the 5 miles I've driven so far). Getting the bike (temporarily) back on the road has made me discover what appears to be a "new" problem - sighs. If I open up the throttle and release it again and then immediately pull the clutch, the revs increase as if the throttle is still held open. This can last a few seconds. The same happens when changing gear. It's as if something holds the throttle open for a few seconds before it then re-closes itself. And it seems to get worse as the engine warms up. I haven't yet checked the lie of the throttle cable runs for any snags (it's too early for that but will do later this morning) but I'm pretty sure that's not the problem. I did notice when cleaning the carbs (again) that one of the sliders was a bit "sticky" when both rising and falling and now wonder whether that could be the problem. I did try gently cleaning the slider and carb body where the slider runs up/down but didn't want to go at it too hard in case of damaging something. Could it be a sticky slider causing the problem or something else causing the symptoms? If I'm forced to remove the carbs a third time to tackle it, does anyone have a suggestion how best to remove the stickiness from the slider without wrecking the plastic of the slider or damaging the bore of the carb in the process? Starting to drive me crazy but I suppose all this shows it's best to do things properly once........
#14
That looks good. I have a tiny little guy I bought at a Honda dealership that hasn't been installed yet, not sure you would have to worry about fuel starvation anyway. It is barely larger than the fuel line diameter. If you have issues still, I'll tell you how mine worked when I get it put in. My bike is rideable so I don't want to take my tank and carbs off yet as I need to figure out my idle problem as well.
#15
The fuel filter is fitted and seems to be working well (at least for the 5 miles I've driven so far). Getting the bike (temporarily) back on the road has made me discover what appears to be a "new" problem - sighs. If I open up the throttle and release it again and then immediately pull the clutch, the revs increase as if the throttle is still held open. This can last a few seconds. The same happens when changing gear. It's as if something holds the throttle open for a few seconds before it then re-closes itself. And it seems to get worse as the engine warms up. I haven't yet checked the lie of the throttle cable runs for any snags (it's too early for that but will do later this morning) but I'm pretty sure that's not the problem. I did notice when cleaning the carbs (again) that one of the sliders was a bit "sticky" when both rising and falling and now wonder whether that could be the problem. I did try gently cleaning the slider and carb body where the slider runs up/down but didn't want to go at it too hard in case of damaging something. Could it be a sticky slider causing the problem or something else causing the symptoms? If I'm forced to remove the carbs a third time to tackle it, does anyone have a suggestion how best to remove the stickiness from the slider without wrecking the plastic of the slider or damaging the bore of the carb in the process? Starting to drive me crazy but I suppose all this shows it's best to do things properly once........
#16
[QUOTE=KMCBR1000FM;1315935I haven't yet checked the lie of the throttle cable runs for any snags (it's too early for that but will do later this morning) but I'm pretty sure that's not the problem.
I did notice when cleaning the carbs (again) that one of the sliders was a bit "sticky" when both rising and falling and now wonder whether that could be the problem.[/QUOTE]
The throttle cables would be my first port of call, might also be an idea to turn the handle bars from lock to lock and listen for any change in the idle speed.
Mine were old and sticky and a bit pinched, so I didn't bother with lubing them, I just changed them out for new ones.
The sliders can be checked with the carbs still on the bike, just pull the air-box and you can lift each one up with a finger. They should snap back down fairly quickly, any dragging will affect your throttle response.
If they are slow, it's worth giving them a squirt of carb cleaner and moving them through their range of motion, to see if they improve. It can work as a quick fix.
I did notice when cleaning the carbs (again) that one of the sliders was a bit "sticky" when both rising and falling and now wonder whether that could be the problem.[/QUOTE]
The throttle cables would be my first port of call, might also be an idea to turn the handle bars from lock to lock and listen for any change in the idle speed.
Mine were old and sticky and a bit pinched, so I didn't bother with lubing them, I just changed them out for new ones.
The sliders can be checked with the carbs still on the bike, just pull the air-box and you can lift each one up with a finger. They should snap back down fairly quickly, any dragging will affect your throttle response.
If they are slow, it's worth giving them a squirt of carb cleaner and moving them through their range of motion, to see if they improve. It can work as a quick fix.
#17
Hawkwind2016, thanks for your response. The cables are fine , and it is "as if" the throttle is sticking open causing the revs to race, but the throttle and handgrip snaps back normally so it's not them or the cable that are the problem. I've tried to remove the airbox to access the slides without actually dismounting the carbs but on the CBR1000F that seems impossible (unfortunately). But I get the impression you too think it could be a problem of sticking slider(s). Yes? If so, do you have a preferred way to clean the sliders and carb bore. I've given both a good dose of carb cleaner twice to no avail. Is a gentle wet'n'dry safe for the plastic slider?
#18
I wouldn't advise any abrasives near the carbs at all.
I only suspect the sliders because you said you noticed one of them sticking.
It might also be a vacuum leak, so check all the pipes and connections are tight and not leaking.
I sold my bike a couple of years ago and cleaned the carbs years before that so memories are a bit vague I'm afraid, maybe this vid will help
Also have you balanced the carbs since you worked on them?
I only suspect the sliders because you said you noticed one of them sticking.
It might also be a vacuum leak, so check all the pipes and connections are tight and not leaking.
I sold my bike a couple of years ago and cleaned the carbs years before that so memories are a bit vague I'm afraid, maybe this vid will help
Also have you balanced the carbs since you worked on them?
Last edited by Hawkwind2016; 07-08-2018 at 03:02 PM.
#19
Hi (again) hawkwind2016. P-L-E-A-S-E take a look at my "Can I sand my carbs..." thread as things have moved on (well, backwards actually). I haven't sanded the carbs (you'll be pleased to learn). I won't repeat what I've written in that other thread as it would just be filling up the forum but I'm back to just 3-out-of-4 cyldrs and that's with a fuel filter fitted. I will take a look at that video you linked for me. Thanks again (please do take a look at that other thread) as I need all the morale boosting that's around!
#20
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