DR650 Choking at high speeds

[andrewmclagan]

hi all,

im in Argentina, Bariloche. My DR650SE (2006) is running great... apart from at high speeds (between 50-70mph) if i give her a bit to overtake, she chokes and splutters until i lay off the throttle. I discovered this while overtaking a bus and two cars with on comming traffic... was a near miss. I had a previous problem where the bike would do the same thing at any speed. This ended up being the vacuum hose from the fuel tank (after market over sized tank), not sure if the hose was blocked or kinked as my spanish at the time of this problem was minimal. Although the current problem seems to be the same symptoms apart from happening only at high speeds when accelerating fast.. any ideas.. people?

thanks!

[Big Yellow Tractor]

Could be a similar issue.

It might be a fuel feed problem which could be down to the breather restricting the amount of air into the tank and therefor the fuel flow out. Or a kinked fuel line. If you run with the fuel cap loose does the problem happen ?

How clean is your air-filter ? a choked up filter can give the same issues.

Are you at a higher altitude than your bike is set up for ?

[BlackBeast]

Have you also checked that little white stock filter in the carb inlet - just another possibilty.
Daryll

[shu...]

Check also the little filter for the carb breather tube under the seat. Mine had a little bit of rag sucked into it and showed the same symptoms you're describing.

(# 20 at the bottom of this parts diagram)

Yamaha Suzuki Victory Can-Am Mineola, #1 NY Dealer, Discount Motorcycles ATV Scooters. We sell New and Used. We also ship parts and accessories. Rent a motorcycle on premises.

............shu

[andrewmclagan]

hmm thanks people will have a look at these things this arvo.

thanks

[farqhuar]

Definitely sounds like some sort of fuel blockage. I suggest removing the fuel bowl and needle valve to make sure there isn't any grit or sand in there.

[andrewmclagan]

ok problem solved! It was a seriously blocked vacume hose full of black grit... No idea what the stuff was. Or how it hot there. Was part of the vacume hose after the valve before the little black box... Sorry for the grammer... Writing from a mobile

[andrewmclagan]

ok im on a computer now so i will be a little clearer for everyone.

i blew through the vaccume hose and realised their was a blockage somwhere in the line. So through a process of elimination i discovered the hose connecting to the canister (red stripe, inlet) was block with a large amount of black grit..

no idea how it got there as i just bought the bike.

DR650SE 2006 18000 miles

although now she runs sweet

=andrew

[MikeS]

Don't forget to clean the air filter regularly, it's amazing how much crap gets in there on SA roads.

[AzzaClazza]

Just to add my two cents. I found this thread because I was having the same problem. I had some water in the fuel which I thought was the original issue but apparently not. I've been traveling through Northern India for 5 or 6 days with the problem. It's not so bad at the low speeds one normally does here but when passing or accelerating, the bike sputters badly, top speed only 60kph.
I did the following without any improvements:
-cleaned the air filter
-cleaned the small filter leading to the top of the carby
-cleaned all 3 fuel filters
-took the carby off, ensured all pipes seemed clear, lubricated moving parts to ensure they weren't sticking
I was at wits end. I emailed the dealer and they suggested dismantling the carby completely and cleaning it out. It's spotless on the inside and I've already poked wires into every orifice
In desperation, I finally took it to a local mechanic in Leh. 2 motorbike shops reccomended I use Mohan. He put his hand over the exhaust and gunned the engine. His hand came out black so he said it was getting too much fuel. He popped out a sparkplug and it was black and sooty. All he did was take off the sump on the carb and put a piece of wire inside the intake jet to restrict the fuel flow. Problem solved! He also cleaned the plugs.
He only wanted 100 rupees for his trouble but I was so happy I gave him 500 and a hug. Finally I had full power!
I don't think the problem is entirely related to altitude. It is 3500m here but the problem started 2000m lower. What caused the problem is still a mystery but the simple workaround of a piece of wire in the intake jet has saved my bacon. Hopefully it will save yours too.
If anyone needs a mechanic in Leh, India. Mohan is your man.
FYI: I'm riding a DR650 with under 4000km on the clock.

[Gipper]

AzzaClazza

Is you DR stock ? do Aussie DR's have the EPA blanking plug on the Carb? have you removed this and put an extended fuel screw in the bottom of the carb?

Even though it does sound like a fuel flow issue you should not need to put bits of wire into the jet. The stock DR runs very lean, but the stock airbox also strangles the DR, if you have problems at high elevation, remove the side cover of the airbox and test it, if it improves it, as a minimum you can remove the airbox snorkel to get more air in or you can cut it open more, bear in mind that back at sea level you may have to cover the enlarged hole up as it may run lean (if the fuel screw is in stock position)

How do you have your 3 fuel filters set up ? most DR owners junk the small carb inlet filter as its very small and even a small amount of crud in there will block it instantly, much better to use just aftermarket inline filters, if your fuel filters are close to the engine/exhaust you may also be getting some vapour locking if the ambient air temp is also hot.

If you have not done so already, join the DRRiders forum here:

www.DRRiders.com

- lots of mechanical knowledge for the DR650, as well as using the HUBB of course!

[AzzaClazza]

Hi Grif
The bike does have an aftermarket exhaust and as part of that operation extra holes were cut into the airbox. I don't know if the jet is standard or not, it's size 45. I know I shouldn't have to have had the wire in there but it got me out of a tight spot. I don't know what an EPA blanking plug is...I'll look into it. and there is no adjustable fuel screw. I believe I can get one but it'll have to wait until Istanbul now. I'm planning on changing tires there, fixing headlights and getting a proper mechanic to look at the carby if it's still not running right after I remove the wire.
Question though...if the bike appears to be running well when I'm under 2000m, or under 1000m...should I remove the wire? Can running lean (if it seems to be running ok from my perspective) damage the engine?

[Walkabout]

Originally Posted by AzzaClazza

Can running lean damage the engine?

Yes.
Definitely not recommended.
I suggest you check your spark plug for the correct colour.