Running problems?
 

Hi folks,

I'm currently preping my 99' suzuki dr650SE for an african tour. The main things which are bothering me at the moment is the fact the bike does not start first time and when finally running it spits and splutters as if its missing every other firing, and similarly anything below 3rd gear at slow speed and the bikes feels very ropey. Being a novice to the world of mechanics and motorbikes in general I am guessing it could be due to the carb??

I've recently fitted the 4.9IMS tank and due to the new petcock arrangement had to fit a cap on the vacuum hose outlet, could this be affecting the running?

Also how easy is it to change the steering head berings since these have also seen their last days.

Any help would be much appreciated,

cheers

If this problem is new since you fitted the big tank then check that the carb is getting enough fuel. There is a little sieve filter in the inlet pipe of the carb.

Replacing the bearings is the same as on most other bikes. Quite a job, if you've never done it before. Getting the race of the stem is the hard part. I've had some poor quality bearings recently, probably made in China. Make sure you get good quality bearings from Japan or Europe. If in doubt stick with the genuine Suzi parts.

Cheers beddhist,

Since posting last things have subsequently got worse, the bike has problems starting and when I finally manage to get her going it cuts out immediately when given any throttle.

I'm going to assess the way in which the vacuum hose has been plugged, possibly drain and flush the carb and check the inlet filter, and clean the spark plugs. I can't think of what else to do?

I've seen quite a few posts regarding the reserve level not being completely used after fitting the IMS tank, could this be due to the amount of pressure decreasing above the fuel line and so not delivering the fuel without the vacuum pump? Becasue of the close proximity of the new petcock with the carb the fuel hose between the two forms something resembling an upturned U-bend, again this could be a problem in the delivery of the fuel but can't really be changed since the carb inlet extends upwards above the horizontal petcock outlet?

Similarly when the engine cuts out or is switched off it does so with a clunk, should this be a concern? :confused1:

You raise several issues here:

The problem with reserve in this case is most likely either the upended U bend or the fact that the bottom of the tank is too low for fuel to flow into the carb voluntarily. I have similar problems, but only when the fuel level is low. I take it you have problems even with a full tank?

There is no vacuum pump, there is a vacuum operated fuel tap on the stock tank. When the engine stops there is no vacuum and the tap closes via a spring-loaded membrane.

The clunk: have you checked your bike for the "engine grenade" problem? See separate topic on this deadly issue. If your bike is first registered in 99 then it may be a 98 model and they are ALL concerned, as far as I know.

Interestingly, my former gf's DR had a lound clunk when starting or stopping the engine. The noise sounds horrendous, as if the engine was about to explode, especially if the bike doesn't want to start. Mine didn't have this problem and neither bike has the engine grenade parts. Through a process of elimination I have narrowed the cause down to the starter clutch. I can't see anything wrong with it, but hers lets go a little before engaging when you turn it by hand. The proof came when I swapped it into my bike: I now have the noise and she doesn't. My bike now has well over 140000 km on the clock and the starter clutch has done even more. It still makes this noise every other time I stop the engine. I'm no longer worried about it. (Famous last words... :eek3: )

an upturned U-bend in the fuel line is the perfect way to cause a vapourlock & make the bike run crap. what happens is the heat from the engine causes the petrol to vapourise & rise. this petrol gas effectively blocks the fuel line so you bike suffers fuel starvation. i'd reroute that line in a flatter manner, even if you have to make it longer to do so.

IMS tanks are known to have small plastic particals - unless cleaned out before installation these block the inlet filter on the carby. If that has already been removed then you may have blocked jets inside the carby.

There is no vacum pump on a DR. The vacum line from the carb goes to the standard fuel cock to turn it on .. it does not in any way pump the fuel.

I've managed to clear the inlet filter on the carb, it was full of silty, fibrous dust. Initially I thought this may have solved my problems and after draining and flushing the carb things looked ok.

The bike still seems very boggy and does definately seem to be missing every other firing, I presume this could be a result of fouled spark plugs. I've re-cleaned the tank (it was full of all sorts of rubbish, even metal tags similar to those found on bottle tops) and shoved some Redex in there so hopefully that should sort the problem.

Having cleaned my new IMS tank I'm not at all impressed, especially with the fact that the flow of fuel from the RHS to the LHS in which the petcock is seated is very poor. I can only presume I'll have to lean the bike to one side to get any use of the fuel sitting in the RHS gully, anyone else realised the bad design?

p.s thanks for all the help and advice so far!

I have the same set up as you. You should get at least 350kms on the tank by which time you'll be looking for more fuel as I generally didn't get to the last 2 or 3 Litres in the tank. As fuel quality varies considerably, I normally tried to fill up after 300kms if I could.

Have you also checked the air filter is clean and nothing is blocking the air inlet?

Possibly there is more gunk in the fuel line? From teh right petcock .. you did clean the petcocks?

Most people throw away that fuel filter on the carb inlet.

Sound like someone has put rubbish in your tank .. T'd be geting some carb cleaner and making certain the jets are clean.

For future reference: I found the Clarke tank to be the better choice for the DR. Although smaller (16l) it still gives you a reasonable fuel range of 300km on average.
It fits like a glove (after you realize that you have to remove the black plastic cover thing on top of the frame ;D ), uses the oem tap and isof very decent quality.

Starter noises:
Note that there are two different noises:
A loud clunk at switch off. It happens on all bikes and most of the times when you switch off. Most DR owners don't regard it as scary or unusual for this reason. I think it's caused by the crank not making it to TDC against compression and reversing.

The other noise is a screeching horrible noise notable when cranking the bike. If you listen carefully you will note that the noise occurs when the engine "overtakes" the starter gear in the combustion stroke and as soon as the bike fires up. This noise is related to the starter clutch and the bike will do many tens of thousands of kilometres without breaking. That's why I can't tell you what EXACTLY is causing the problem as I never bothered to fix it (Three of my seven DR650SE of year model 1996, 2000, 2001 and 2007 developed the problem.)
On one of the bikes the starter clutch was replaced after I sold it (rather expensive) and the noise was gone.

For the mentioned running problems take a thorough approach:
If you get enough fuel:
Check air filter & fit new plugs. If that does not help get the carb cleaned.

Veering a little off-topic: I had the screeching noise twice and each time it was lack of lubrication in the starter motor bearings. Relatively easy to fix. I've heard starter clutches on other bikes make horrible clonking and rattling noises, but never screeching.

Remove and Clean the Carb
 

Good luck, safe riding! nnnnnnnnnnnnnnnnn

Remove the exhaust
Remove the starter
Open the starter & lube. Be careful when pulling the rotor out of the rear shield with the brushes, it's a bit of a mission to get it back together, you'll have to push the brushes back and lock them with some wire or a screwdriver.

Re the steering head bearings: Probably the best to buy OEM Suzuki as they come with an integrated shaft seal to keep dust / water out. Not available as generics afaik.
Every bike should have steering head bearings sealed like the ones in the DR (especially the F650GS!)

In addition to the exhaust header you also need to remove the lower oil pipe and move it out of the way and I think the cam chain tensioner.

There are some bushes, probably sinter metal at both ends, put a little MoS2 grease in there. Make sure you know how to retract the tensioner before reinstalling it.