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Drz400 starting problem

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I took delivery of a 2001 drz 400 s at the start of the week which although it has been well maintained and slightly crashed (previous owner was a bike mechanic who left the country after having 2 drz's stollen and several fights with the police trying to get them back. Last straw was a fool driving out in front of him on a roundabout) and the bike has sat for 7 years without being run. I am assured that it was running before he left it.

Anyway... I connected a big battery and a squirt of oil in the spark plug hole and gave it a hopefull crank.

Everything turned as expected, feel pressure at spark plug hole, (waiting on compression tester arriving), plug does spark (dont yet know how to check timing of spark?).

The carb was dry and fuel tank was empty so I put in fuel and flushed the carb and tried to crank with fuel and spark... no joy just a couple of small explosions from the exhaust. ( I assume that this means fuel is getting through, but is not burning in cylinder?)

I stripped the carb and cleaned with carb cleaner anyway which did not help ( no I did not change any carb settings! )

I found a post somewhere suggesting disconnecting a connector with 3 yellow wires which I tried without success.

I am thinking next steps are valve clearances, then check if piston rings are stuck on piston, but I would like to hear any other suggestions before I start stripping down (I am used to 2strokes and am nervous about messing with cams.)

I need to buy some bits before I can try a bumpstart ( missing sprocket and gear selector and cluch lever and rear spindle nut and sprocket bolts and... you get the idea dont worry I got the bike cheep). But was thinking the extra cranking speed might just be enough to get it going?

Any thoughts/ suggestions greatly appreciated.

Also anyone with a cheep spare front wheel or many many other parts please get in touch and I can take them off your hands ; )

Before pic attached (came with plastics fuel tank seat computer and a pile of broken bits lol)

Edit: one other thing... while cranking the engine if I put my hand over exhaust I can feel it blow and suck alternately is this normal or are the exhaust valves stuck open? Seems unlikely because I can feel pressure at spark plug hole but not sure whats normal on this beast.

1382603635956.jpg

Edited by alienargg

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I took delivery of a 2001 drz 400 s at the start of the week which although it has been well maintained and slightly crashed (previous owner was a bike mechanic who left the country after having 2 drz's stollen and several fights with the police trying to get them back. Last straw was a fool driving out in front of him on a roundabout) and the bike has sat for 7 years without being run. I am assured that it was running before he left it.

Anyway... I connected a big battery and a squirt of oil in the spark plug hole and gave it a hopefull crank.

Everything turned as expected, feel pressure at spark plug hole, (waiting on compression tester arriving), plug does spark (dont yet know how to check timing of spark?).

The carb was dry and fuel tank was empty so I put in fuel and flushed the carb and tried to crank with fuel and spark... no joy just a couple of small explosions from the exhaust. ( I assume that this means fuel is getting through, but is not burning in cylinder?)

I stripped the carb and cleaned with carb cleaner anyway which did not help ( no I did not change any carb settings! )

I found a post somewhere suggesting disconnecting a connector with 3 yellow wires which I tried without success.

I am thinking next steps are valve clearances, then check if piston rings are stuck on piston, but I would like to hear any other suggestions before I start stripping down (I am used to 2strokes and am nervous about messing with cams.)

I need to buy some bits before I can try a bumpstart ( missing sprocket and gear selector and cluch lever and rear spindle nut and sprocket bolts and... you get the idea dont worry I got the bike cheep). But was thinking the extra cranking speed might just be enough to get it going?

Any thoughts/ suggestions greatly appreciated.

Also anyone with a cheep spare front wheel or many many other parts please get in touch and I can take them off your hands ; )

Before pic attached (came with plastics fuel tank seat computer and a pile of broken bits lol)

 

 

What colour is your spark? A healthy spark is usually a blue/purple kind of colour, white spark will only detonate an ULTRA flooded engine, and I suspect that is what was happening with the backfiring. If its been sitting for 7 years, theres a good chance the plug has degraded. Start there, with a fresh plug.

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Its a blueish spark and plug looks like new but I will try a new one anyway.

Thanks

 

 

With regards to being used to two strokes and nervous with the extra pudge, you should be able to take the Chead and all the valve train off in one clump. YOu'll have to disconnect the camchain obviously but that shouldn't be too hard. Then you'll be able to stare straight down at hte piston and rings and see if there an obvious problem. Check your clearances while the head is sitting on a bench. 

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i'll bet the rings are rusted in their grooves = low compression. 

 

pull the tank, then the plug, and put the crank at bottom dead center (or wherever low) and dump some penetrant in there. let it sit a few days. then suck all you can out with a hose, and try again. 

 

it's going to take some time to break the rings loose with the starter. 

 

as soon as it fires and runs, it's time for an oil change or three to flush out all that penetrant, water (from sitting) and old sludgy oil. 

 

clean the screen too. it's likely gummed up. 

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What sort of penetrant? I hear wd40 should not be taken internally I dont want to spray something in to avoid dismantling only to have to dismantle to replace seals etc.

Lots of snake oil suggestions online, but which are safe to use?

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Did you clean pilot jet? Really clean it? Is the vacuum line from carb to fuel switch hooked up?

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I squirted carb cleaner through every orifice I could find, in both directions so I think I really cleaned it?

Vacuum line to fuel tank? The tap has a single outlet which I connected to the carb with a new piece of clear hose. Am I missing something? Fuel runs from the carb drain plug if I unscrew the drain screw. So I thought that was fine.

I tried a hotter twin spark plug the local bike shop gave me just to check but still no run.

Have squirted oil into cylinder to try to create a seal if the rings are stuck on the piston... no worky

Really appreciate the suggestions keep them coming and I will keep on trying them but I want to do a compression test before I start dismantling the top end because I am still hoping it is something simple...

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I squirted carb cleaner through every orifice I could find, in both directions so I think I really cleaned it?

Vacuum line to fuel tank? The tap has a single outlet which I connected to the carb with a new piece of clear hose. Am I missing something? Fuel runs from the carb drain plug if I unscrew the drain screw. So I thought that was fine.

I tried a hotter twin spark plug the local bike shop gave me just to check but still no run.

Have squirted oil into cylinder to try to create a seal if the rings are stuck on the piston... no worky

Really appreciate the suggestions keep them coming and I will keep on trying them but I want to do a compression test before I start dismantling the top end because I am still hoping it is something simple...

 

You're probably going to need to remove each jet to properly clean ..... replacement of the jets might be prudent since it has sat for so long.

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What sort of penetrant? I hear wd40 should not be taken internally I dont want to spray something in to avoid dismantling only to have to dismantle to replace seals etc.

Lots of snake oil suggestions online, but which are safe to use?

 

 

i'd use marvel mystery, or wd40, or anything that won't dissolve rubber seals for obvious reasons. 

 

the important part is that it -begins- to break the rust apart. the mechanical action of the piston slapping back/forth with each stroke will hopefully loosen the rings the rest of the way. if not, the rust will jam them in the grooves until there is very little compression at all (40-60lbs) and then require disassembly. if it does, a little time with a .004" feeler gauge after soaking in a more aggressive penetrant (kroil/pbblaster) will loosen the rings.

 

then it's up to you if you want to reinstall the old or replace with new. if i had the piston out, i'd replace the rings, toss on a new head/base gasket, check the valves, install a MCCT, cut off the exhaust auto-decomp mechanism, and enjoy a nice reliable bike for a while. 

 

keep in mind that rust on the rings will go other places you don't want it to during starting. that's why i suggested a few oil changes directly after it finally starts. 

 

 

if you want to see how to do a compression test (which you need at this point) see here for a quick way to disable the auto-decomp mechanism and get a good reading:

 

http://www.thumpertalk.com/topic/918152-2004-drz400-will-not-start/page-2#entry9579509

 

 

also, you can see very easily what (mine were over heated/jammed) stuck rings look like in this post:

 

http://www.thumpertalk.com/topic/918152-2004-drz400-will-not-start/page-4#entry9586906

 

 

 

i hope i'm not muddying the waters. :)

 

i'm assuming you've already tried a LITTLE bit of starting fluid to start the bike, and ruled out fueling issues. 

Edited by ohgood

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Ok so update time...

Compression gauge turned up but does not fit so might scrap that idea for now.

Clutch lever turned up allong with rear sprocket so just need the rear spindle bolt and gear lever and I can try a jump start but I noticed the clutch is creeping so that might be eventful with no working brakes.

I have taken the rocker cover off and checked the flywheel is alligned with tdc it might be 2 or 3 degrees out but the cams are aligned with each other.

One thing I did notice as I turned the flywheel and watched the cams turning after the intake cam releases and i turn the flywheel another 5-10 degrees there is a sort of pop/click. I have not identified what causes it but I wonder if an intake valve is sticking? or it could be the auto decompression doing its thing and I just cant see?

I had hoped the engine would run before I needed to buy loads of parts so I wouldnt have doubts about wasting cash on a lost cause but as long as I can get it running I will have to spend a little less than the cheepest (running) drz's on ebay. And im having loads of oily fun scratching my head.

Should get feeler gauges on monday so will dig a bit deeper then.

Turns out the bent front wheel rim broke 3 spokes and the brake disk and sheared a lobe off the hub so no new rim and rebuild job im looking for a full front wheel ideally with disc and possibly with new spindle if this one is bent. Anyone got a rusty spare in uk?

And thanks for the help, every post takes me closer to muddy fun.

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problem solved?

I got the cylinder off and found 2 rings glued into the piston by small carbon deposits.

Got the top ring out with a 0.05mm feeler gauge after half an hour but the other ring is a bit more stubborn.

Everything else looks good but a magnet on a stick saved me from having to split the crankcase when I dropped one of the cylinder locating dowels in to the bowels.

Next time will remove cylinder from the left side of the bike so they fall on the floor instead ;-)

Whats the best thing to remove carbon anyone tried oven cleaner?

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