I acquired an 04 DRZ400s with an ign prob. Spark plug left out approximately 2 years. sad face.

I traded work for a non functioning DRZ400s. it was parked because it lost spark. While it sat it was "diagnosed" to have a failed CDI box. This person left the plug out and the engine took on a lot of water. Now I assume the motor must be at least partially torn down and rebuilt, but to what extent? any advice would be helpful....

Unforunately you won't know the extent of the damage until you pull the head / jug / piston. I would say at a minimum you will need a new jug / piston.

Hit it with a ton of wd-40 if it's seized.

Let it sit with the wd-40 for a couple days.

Then try to crank it over.

If it doesn't, more oil and a few more days.

It should free up.

 

Clean the crud out of the carb.

 

Then change the oil and coolant. Run it for a bit.

Then change the oil and coolant again.

Should be good to go, or at least until you feel the need to rebuild it.

Alright. It's been a while and I've gotten the bike out of the woods and had it apart. A lot of WD-40 and also 10w-30 motor oil went into the cylinder and now it turns over beautifully via the flywheel nut under the side case. That made me feel better. On to the main problem- no spark. apparently the bike charges its battery when run for an hour or so, but I discovered that it was mistreated ie. bump starting with a low low battery, jump starting off a truck or car, you name it. anyway it has been abused and now doesn't run. Bikes 99% perfect, but it doesn't have this one thing.. I want to piggyback on other people's knowledge if possible and I'm sure the machine will function some day 


Alright. It's been a while and I've gotten the bike out of the woods and had it apart. A lot of WD-40 and also 10w-30 motor oil went into the cylinder and now it turns over beautifully via the flywheel nut under the side case. That made me feel better. On to the main problem- no spark. apparently the bike charges its battery when run for an hour or so, but I discovered that it was mistreated ie. bump starting with a low low battery, jump starting off a truck or car, you name it. anyway it has been abused and now doesn't run. Bikes 99% perfect, but it doesn't have this one thing.. I want to piggyback on other people's knowledge if possible and I'm sure the machine will function some day 

No spark ? .. test the stator

Be prepared for some smoke pouring out of the exhaust when you eventually get to running .

1: just because it turns over, does not mean it's ready to run.

 I think you'll find low compression (frozen rings) if you check.

2: You know it has no spark? Or you just think that is why it wont start?

3: Why was it left in the woods?

4: Go to the FAQ and follow the diagnostics for checking the stator / charging system.

I am hoping and praying that 'out of the woods' is just a turn of phrase and not the actual location... :(

 

+1 to the compression check.

Diagnosis fundamentals:

1. Compression (mechanical - includes valve and timing)

2. Electrical (stator, CDI(which is by process of elemination, unless you have the right tools and knowledge))

3. Fuel - air mixture. (Carb)

The first two can be misread as the third.

 

If you put a lot of time and effort into the electrical and the pump won't hold compression...time and money wasted.

Edited by clutch23w

Piston and cylinder are the least of my concerns.  Bearings in the lower end are suspect if there was any water in the oil.  Even if not, sitting outside for extended period of time with no plug can damage the hardened steel bearings (not very resistant to corrosion)  Bearing steel has lot of carbon in it to form  wear resistant hard carbides.  The carbides in the iron matrix forms a nice little battery, all it needs is electrolyte (water) to completer the circuit.

 

I suppose there is little to loose by running it.  It is either damaged or it is not at this point, but me, I would take it apart and evaluate what I find.  Minimal cost for a few gaskets if all is well.  If there are problems then you know what you have before you spend money on the electrical system.

Piston and cylinder are the least of my concerns.  Bearings in the lower end are suspect if there was any water in the oil.  Even if not, sitting outside for extended period of time with no plug can damage the hardened steel bearings (not very resistant to corrosion)  Bearing steel has lot of carbon in it to form  wear resistant hard carbides.  The carbides in the iron matrix forms a nice little battery, all it needs is electrolyte (water) to completer the circuit.

 

I suppose there is little to loose by running it.  It is either damaged or it is not at this point, but me, I would take it apart and evaluate what I find.  Minimal cost for a few gaskets if all is well.  If there are problems then you know what you have before you spend money on the electrical system.

Noble is dead on.... It was a concern of mine as well. Seeing as it was going to be run either way.. I only commented on things that would keep it from starting / running 

It runs!! So many lessons. New cylinder + Rings, Stock piston was cleaned and reused, absolutely patient break-in of the recommended 3 hrs. Absolutely spectacular machine work on head  by a local shop

Hhaha awesome 18months?

Hhaha awesome 18months?

Spectacular machine work takes time,  lol

More and more little details about this bike keep surfacing- previous owner had allowed chain to run very loose, which effectively removed the protection of the slider, to the point where it grated into the swingarm at least 1/16 ". It does seem to be in a critical spot, and the aluminum is fairly thin there. Is this a major concern?

if its not through the metal i wouldnt worry about it .. you do need to replace things and get some new components if you expect it to be reliable though ..

Now I am going through the carburetor ( repeatedly) to try and bring it back to it's former glory.. Totally stock except fuel screw (TT) installed, 142.5 MJ, stock needle.  . My first goal is to try and make it run like it used to after a rebuild. I noticed the spark was weak and orange red when I removed the plug, which seemed like a culprit. The stator was replaced initially to fix the ignition problem. I am purchasing a new plug today to see if it could be an issue, and am planning on changing the main and pilot jet. Stock exhaust

All the problems I am having with this carb seem pretty familiar to owners of this bike ,Wide open it seems flawless, but in slower riding has  many aggravations, high idle, idle dropping off , then stall with a very difficult restart.  . Coming off of very simplistic 2 stroke style carbs, some of this is hard to understand for me. I thought I knew this stuff! 4 strokes are a little tougher. back to work

Don't forget that since you're in the People's Republik to remove the blanking plug and clean and adjust the idle screw.  (If that hasn't already been done.)  It may be covered with an aluminium plug that can fool into missing it.

Alright the bike did start after cleaning and rebuilding the carb-- new plug installed NGK CR8E, no ability to idle normally, only with idle speed screw turned up excessively. Also, the stator was replaced early on in the process of fixing this bike. .and it has run normally for a short time when first reassembled.

I would suggest you are having trouble with your Pilot Air Jet circuit and fuel screw/idle settings. Check to make sure the fuel screw tip has not broken off in the carb. Stock or aftermarket. When you went through the carb did you just open it up and clean it or did you get some rebuild kit/ replacement parts for reassembly of the cleaned carb? The orifices for the jets and PAJ are small and easily clogged which can affect how it runs. Is the ACV diagphram in good condish? No cracks? The little o-ring under the top cap in place? How about the float needle end and the float needle seat o-ring and little screen? Did you check them? Also is the vacuum line to the petcock hooked up?

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