I have an almost new 2012 2.9 that is stalling on downhills. I have adjusted the float (in both directions actually, as an experiment) but that didn't help. I found the pilot to be clogged 2 times when I took the carb apart. I therefore drained the tank, put on new fuel lines and an inline filter. No help (though the jet is now staying clean). Bike runs really well otherwise. One of our local riders is trying to modify an early 2013 to put a "T" on the main fuel line. One branch will run to the carb and the other will return to the tank through a new inlet. He is wondering if this will prevent the pump from forcing too much fuel into the carb when the float should have shut off the fuel flow. Apparently the newer 2013s have this.

Anyone have any suggestions?

Love to know if anyone else has this problem, anyone come up with any fixes? We ride some very steep and long downhills here. It is a bit of a pain to have to think about bliping the throttle to prevent stalling when one should be focusing on brake control and survival.

Thanks in advance

I would look for a pop off tester

Watercraft dealers would have used these in the carb days

You would hold the carb upside down and test to see if the needle leaks and as you pressure it up it would pop and then reseal

Look for a steady weep to tell if the needle is leaking

You could also check fuel height (not float level) it should normally be near the gasket surface

You would make a tool to replace the drain plug and put a clear hose out so you can hold it alongside the carb body with the bike running

Look at this http://www.splatshop.co.uk/blog/2012/12/setting-the-float-height-on-the-keihin-pwk-28/ as a referance.

On my OKO, I went a mm or more so higher(lower level when upright) than that without issue, So basically flush with the appendage.

Contact Splatshop for more info.

I would look for a pop off tester

Watercraft dealers would have used these in the carb days

You would hold the carb upside down and test to see if the needle leaks and as you pressure it up it would pop and then reseal

Look for a steady weep to tell if the needle is leaking

You could also check fuel height (not float level) it should normally be near the gasket surface

You would make a tool to replace the drain plug and put a clear hose out so you can hold it alongside the carb body with the bike running

If you really want to see whats going on in the float bowl then easiest thing is to buy a oko clear float bowl if your bike is running a keihin which I suspect your bike is

http://www.ebay.com/itm/270876397516?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Have run 1 on my bike for a year or so & it's been worth every cent, just ordered another couple for another bike & a mate's beta factory

Here is a great reply I got from Splatshop

Yeah the valve needs to be closed but the spring wants to be fully extended. Many of the new bikes come with the float set higher than we show in the picture but we find on the Shercos they run best in the position show, it's a personal opinion though so please experiment and go with what you prefer.

The new bikes do come with a T piece in the fuel line, it goes between the Pump and the Carb and the pipe runs up to just above the breather pipe hole in the tank.

It uses the another nipple the same as the breather to go back into the tank:

http://www.splatshop.co.uk/sherco-fuel-tank-breather-nipple-2010.html

This is in my opinion designed to give the bike a little more fuel when it needs it the most and as you say to give the fuel somewhere to go if it over pressurisers.

There is a relief valve in the pump to do the same kind of thing so it might be worth checking this is clean and is still working, it's just a plastic ball and spring that seals a passage way between the two sides of the pump.

The main problem we found with the 2010 and 2011 bike was the angle of the carb, on the 2012 bike they lifted the front of the carb and dropped the back to bring it a bit closer to level. You might be able to do something similar with your if all else fails, the 2012 airbox will fit and you could probably get a new 26mm rubber manifold and cut it to lift the carb slightly and blend the top the manifold so you get a smooth flow.

In case anyone else has this problem, we have it fixed. Local rider and I both had the issue, we both did the same mod and both our bikes are running great now.

We basically added the 2013 fuel bypass line. The fuel now goes to a T piece after the pump. One branch goes to the carb and the other goes up to the top of the fuel tank and can dump the fuel back in there. This way the fuel pump is not pushing too much fuel Into the carb. When the float closes the fuel line, it now runs back up into the tank.

Bike runs better generally and no more stalling on downhills.

Hope that can help someone.

Good to know! Do be sure to pass on the feedback to Splatshop Chris as well, as he may have others inquire.

Did you get any pics or part numbers of the new installation?

I already emailed Chris at Splatshot and let him know. I will post a pic when I next have the plastic off.

Here is the new fuel line (yellow one).

I'm having the same problem with my 2013 250 so I'll give this mod a go, did you just drill and tap the tank to fit the extra nipple or did you get a pad welded on first for extra thickness ?

I just drilled and tapped. Worked well. had to be careful with the filings in the tank after but I cleaned it out really well. Generally, bike runs much better now. Glad I did it.

I guess I don't get around much.

There's a fuel pump on a carbureted engine?

yes mate

Bummer.

More stuff = more trouble, in my experience.

And the benefit is?

Lower C of G?

I could probably wear my tool bag lower and accomplish that.

Charlie, where have you been! They put the Tank where the airbox went and the Airbox where the tank went three or more years ago!

Simple enough, riding lawnmower technology on vacume operated pump! Better for balance on the rear wheel! And the air intake is close to being a WWII submarine!