A forum for owners of Yamaha TTR250 trail and enduro bikes!

Mike Wright · Veteran Member

Inline fuel filter information - hints & tips

TT-R250M · Super Guru

Inline fuel filter

noeyedear · Senior Member

I also have a fuel filler fitted. Is a lot smaller than the one in the picture. But not to small as to restrict fuel flow. My one is for a trial bike not sure of model

Maniot · Veteran Member

The above comment about a 6mm in-line filter being too small is interesting.....I have experienced misfiring/fuel starvation on the 1998 TTR purchased last week.....there is a tiny filter fitted (pencil diameter) which I was suspicious about.....I'll try fitting a bigger one I think! .......perhaps along with a quick-release coupling for easier fuel tank removal while at it !

locky · Guru

Petrol filter.

Cubber · Super Guru

I bought my TTR from the Guru in August 2010.

It didn't come with any petrol filter other than the screen in the tap and the one (if there is one) in the carburettor. wink

It's still running with no problem.

You put the "clean" petrol in, presumably, and therefore it's your choice. hmm

Martyn

ago · Veteran Member

locky I installed one of those car type clear plastic canister filters just after I bought my 2011 model which had less than 300 klms on it. I just cable tied it to the frame adjacent to and above the level of fuel in the carby on the l.h.s. never had any feed problems with it and at least you can see if fuel is flowing to the carby visually.

TTRfan · Super Guru

I always used to run inline filters but have found that the cheaper plastic ones get brittle with age and the inlet/outlet pipes can break off making it a tad awkward to repair if you are out on the trails.

I have sourced a small metal filter which can be split to check/clean the internal filter but it gives no visual clue as to whether petrol is going through it. It's been on the bench for a long time and just haven't felt the need to fit it.

I now just rely on the in-tank tap filters and the one above the float valve and haven't had any issues.

It would be unusual for a carb to be affected by dirt in the petrol on the TTR I would think. Water in the carb is the most common problem and a quick drain of the float bowl usually clears both any water and debris.

Brian

ago · Veteran Member

brian most of the good quality filters of all types down here are made by a company called RYCO. I have used the cheap filters and i'm wondering how your consumer standards people would allow a fuel filter that could represent a fire hazard from cracking or breaking to be sold. I would imagine the plastics used for fuel filters would have to meet strict manufacturing guidelines similar to fuel containers. it's amazing the amount of foreign matter I have seen inside the float bowls of older cars with carburetors over the years. unfortunately with a single cylinder machine if you get a blocked jet the engine will probably stop unlike multiple carby setups.

DC · Veteran Member

Inline fuel filter

peteBLUEttr · Super Guru

CLICK

DC · Veteran Member

Thanks for that link Pete. What sort of duration/miles would you expect to change it after? Just curious really, they are cheap to change.

peteBLUEttr · Super Guru

They seem to go on forever. Petrol is ususally pretty clean to be fair, and you have a plastic tank so theres no issue with rust

locky · Guru

I planned to fit one but didn't bother in the end. The filter on the fuel tap and in the carb should be enough.

Bsturkie · Member

I have seen where ethanol gas has made the pet**** filters crumble inside of the tank. Even though I don't run ethanol gas I use inline filters on everything possible. I scored a bag of 20 or so on Ebay for a great price.

TTRfan · Super Guru

Robin Webb sent me some info on the inline filters he uses. He uses his TTR in foreign climes and in some places where the cleanliness of the fuel might be questionable!

This is what he said:

"I still rate these filters. Stronger than plastic and still lightweight.

They are old Motrax stock that’s still floating around the system.

I used to use 6mm but found the 8mm work a bit snugger in the ¼’’ Motion Pro fuel line I use.

They have foam elements. Pretty thorough filtering.

Over some time and I’m guessing with some dodgy/variable fuel over-seas, the foam does breakdown and the collect in the carb filter. Probably to no ill effect.

But for belt and braces I added the metal filter mesh to catch the bits of foam.

The mesh needs a little shaping to make it concave. Then it fits neatly between two 2mm thick o-rings and is clamped in place when you screw the two parts together.

Also I used different/ stronger hose clips to hold in place.

Just checked prices. They pretty cheap out there. Like less than £5 when they used to be £10.

Plus J&S have 20% off at the mo.

5/16’’ is the 8mm as I’m sure you know."

Links:

O ring 7mm ID 2mm cross section.

https://www.ebay.co.uk/itm/Metric-Viton-Rubber-O-Rings-2mm-Cross-Section-1mm-30mm-ID-UK-SUPPLIER/141455807170?ssPageName=STRK%3AMEBIDX%3AIT&var=440603746052&_trksid=p2057872.m2749.l2649

filter mesh

https://www.ebay.co.uk/itm/L11091-RC-Nitro-Engine-Fuel-Filter-Wire-Meshing-Mesh-Paper-x-10-11mm/331368301417?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Motrax filters:

8mm

https://www.jsaccessories.co.uk/buy/motrax-mf2-micro-filter-alu-5-16%22/3741.htm