Fuel lines with a Mikuni How to run them?

photoguy_43420 · Apr 28, 2020

Changed my old hard fuel lines. I never liked how they were ran. How are others running fuel lines with a single Mikuni?

Thanks,
Guy

NPeteN · Apr 28, 2020

Both lines down to a T on bottom right side of carb, up the right side through a filter and over the top to the inlet on the left side.

This worked well for me but boredom had me change to a similar configuration but in the space above/infront of the carb. I don't like it as much.

river700 · Apr 30, 2020

Right side through filter, over manifold to T connecting left tap and into carb. Filter only does rt tap, left is reserve.
Done by PO, thinking of a change so both sides get filtered.

Peavey Jeltz · Apr 30, 2020

90° petcock fittings like http://www.rockypointcycle.com/p-2940.html make for a neater Mikuni fuel line setup. These are 1/4" (6mm) and the nipple on the Mikuni is 8mm. You can find 6mm x 8mm T fittings which also help sanitize things. Over the top of the manifold and T pointing down to the nipple on the carb.

swooshdave · Apr 30, 2020

Fuel lines with a Mikuni How to run them?

I’m not saying this is the best way but it’s one way. One advantage is that it doesn’t have loops hanging down.

river700 · Apr 30, 2020

river700 said:
Right side through filter, over manifold to T connecting left tap and into carb. Filter only does rt tap, left is reserve.
Done by PO, thinking of a change so both sides get filtered.

Craig · May 1, 2020

I like the loop , most debris will settle there , no filter , never an issue, do drain tank and carb dry yearly .... “Old Brits” I think used to list fuel line setup for single Mikuni , with photos ....

jaydee75 · May 1, 2020

I used an Amal filter to turn the corner on the left and then teed the lines together on the right side.
Jaydee

RoadScholar · May 1, 2020

If you have the 90 degree petcock fittings I recommend coming off the right petcock, going around the back side of the carb, put the "T" fitting directly over the carb's fuel input nipple with a short piece of fuel line between the nipple and the "T", then continue to the left petcock; making sure that the fuel line does not make contact any point that can start-up an abrasion process. This configuration will give you ample room to fit 2 fuel filters and keeps the fuel line as far away from the engine's heat as possible.

Do check to see what alcohol percentage the line you select tolerate, the poly line that I am most familiar with is speced up to E10. I recommend the Continental 7mm braided, cloth covered line as used on VWs; not hard to find.

Best

swooshdave · May 1, 2020

I’m still a big fan of Tygon fuel rated lines. They do tend to get hard after ten years or so.

RoadScholar · May 1, 2020

swooshdave said:
I’m still a big fan of Tygon fuel rated lines. They do tend to get hard after ten years or so.

Probably the best line out there, but last time I looked into it the price was $45/foot. At $4.25/foot I believe that the Continental braided cloth covered would appear to offer a better value proposition; many of the BMW airheads still have the Continental that they came out of the factory with. If Tygon has become competitive please let us know, it is the best.

Best.

NPeteN · May 1, 2020

RoadScholar said:
Probably the best line out there, but last time I looked into it the price was $45/foot. At $4.25/foot I believe that the Continental braided cloth covered would appear to offer a better value proposition; many of the BMW airheads still have the Continental that they came out of the factory with. If Tygon has become competitive please let us know, it is the best.

Best.

Tygon is cheap, unless I'm missing something it's like $2.50/ft