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Filter or no filter?
Posted: Wed Feb 11, 2015 5:45 pm
by alanscottj
Tried running my scooter today without the filter, runs much, much nicer. The scoot (muggy 198)was dyno'd with a filter on and I am using a power jet and have an EGT meter so I am able to tweak the carb if temps get too hot, I also have CHT to keep an eye on that too.
What are your thoughts on running without a filter???
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 5:50 pm
by bristolmod
worn rings; worn bore; crap all over the engine bay area; get something big sucked in (e.g. a stone or young child) then its bye bye top end. mixture could go "lean" very quickly= holed piston etc.
Chris
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 6:05 pm
by soulboy
I used to run my balls out tuned m.b 190 t5 with no filter no hassle

Re: Filter or no filter?
Posted: Wed Feb 11, 2015 6:13 pm
by Adam_Winstone
Much of this depends on what type and size of filter you are running. Any decent filter should make very little difference to performance, however, too many of the filters that I and others have been sold by scooter dealers are far too small and far too restrictive to allow the motor to breathe correctly, choking intake and killing performance
Adam
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 6:31 pm
by alanscottj
Adam_Winstone wrote:Much of this depends on what type and size of filter you are running. Any decent filter should make very little difference to performance, however, too many of the filters that I and others have been sold by scooter dealers are far too small and far too restrictive to allow the motor to breathe correctly, choking intake and killing performance
Adam
I have a small RamAir sponge filter at the mo. I should add that the only reason I took it off is that it was running a bit rough, probably because of the weather as it has been running fine. As soon as I took it off the difference was significant.
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 6:40 pm
by Grumpy225
alanscottj wrote:Adam_Winstone wrote:Much of this depends on what type and size of filter you are running. Any decent filter should make very little difference to performance, however, too many of the filters that I and others have been sold by scooter dealers are far too small and far too restrictive to allow the motor to breathe correctly, choking intake and killing performance
Adam
I have a small RamAir sponge filter at the mo. I should add that the only reason I took it off is that it was running a bit rough, probably because of the weather as it has been running fine. As soon as I took it off the difference was significant.
Sounds like it's time to clean the filter.
Using the correct filter set up there should be no noticeable decrease in air flow.
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 7:00 pm
by alanscottj
Sounds like it's time to clean the filter.
Using the correct filter set up there should be no noticeable decrease in air flow.[/quote]
Your probably right, I haven't cleaned it yet. Might even consider getting the breathe right one?
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 7:08 pm
by Adam_Winstone
If it is a small RAM then it is probably time to give the filter to someone that wants a remote filter for a standard LI125!
RAM filters are very good but their double skinned construction makes them pretty restrictive unless the filter has enough surface area to flow enough air at a fast enough rate. I bought a RAM air from a dealer and it was instantly a huge restriction to flow and performance... so I bought a bigger RAM filter, which made the situation noticeably better but I still found it was choking the performance on a mild tune 200 with 30mm carb. I then made the change to a Breathe Sweet filter (one layer of less dense foam) and performance then matched the open mouth performance.
I did find that I could use the bigger RAM filter on a standard 175 iron barrel that I was running a 28mm PHBH with, and RS clubman, and this didn't restrict the performance. However, my small RAM filter went straight in the bin!
Adam
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 7:15 pm
by alanscottj
Adam_Winstone wrote:If it is a small RAM then it is probably time to give the filter to someone that wants a remote filter for a standard LI125!
RAM filters are very good but their double skinned construction makes them pretty restrictive unless the filter has enough surface area to flow enough air at a fast enough rate. I bought a RAM air from a dealer and it was instantly a huge restriction to flow and performance... so I bought a bigger RAM filter, which made the situation noticeably better but I still found it was choking the performance on a mild tune 200 with 30mm carb. I then made the change to a Breathe Sweet filter (one layer of less dense foam) and performance then matched the open mouth performance.
I did find that I could use the bigger RAM filter on a standard 175 iron barrel that I was running a 28mm PHBH with, and RS clubman, and this didn't restrict the performance. However, my small RAM filter went straight in the bin!
Adam
Thanks Adam, tbh it's my first time with a tuned motor so picking up knowledge as I go, but what you say makes total sense.
Re: Filter or no filter?
Posted: Wed Feb 11, 2015 7:54 pm
by ipman
a piece of ladys tights and an elastic band adds abit of protection from rocks,kids and oily fingers