Still trying to get the bandit going...

Ok so I've done about everything I think I can possibly do.

Carbs are clear, fuel is flowing, bike is good electrically... but still not quite there.

I cranked the crap out of it this afternoon after squirting fuel through the carbies into the cylinder and it seemed to kick over a couple of times, but it sounded pretty weak. I reckon she's either got low compression or the timing is out - suppose the latter is better than the former. Not sure how I can test the compression without getting a gauge but as you're supposed to do it with a warm engine I wonder if it's even worth the investment.

Open to ideas though - anyone know how I can check the timing?

 

Yes I'm pretty sure they are clear. I didn't completely disassemble the carby but I cleared all the jets accessible through the bowls and also the needles and plungers. Everything looked good, bone dry.

Yes I have checked for spark and it looks pretty good.

The battery is brand new

Yes I have tried all choke settings

I'm not sure start ya bastard will help much - I'll explain more below.

The bike was in bits because the previous guy was trying to do what I am doing but gave up when the magnets fell off the flywheel. He said it definitely runs, although he admitted it was a bit rough.

As for the second this is where it gets interesting. I squirted 1ml of fuel though the carby into each cylinder and kicked her over. Nothing much changed, she did kind of find a bit more but nothing significant (this is why I think start ya bastard won't have much effect). THEN i changed the firing order so I knew it was WRONG. It is supposed to be LHS 1&4 and RHS 2&3 but I recalled that when I got the bike it was LHS 1&3 and RHS 2&4 plugged in. So when I made it 1/3 and 2/4 it almost started, albeit very weakly. I'm starting to think some dildo mechanic had no freaking idea what the firing order was (it takes some brains to look on the internet to find the info about an imported bike) and probably messed with the timing to try and make it work on the wrong firing order...

I probably could, but compression tests are supposed to be done when the engine is warm so I'm not entirely sure how accurate it would be. I've got brand new oil in it so not to keen on flushing my $60 down the toilet but if it comes to that I'll try the ajax thing. As for carbon build up I wouldn't be surprised. The old plugs were quite carbonated, and looking in the exhaust it is also quite carbonated on the inside. so the valve seats may be an issue - still I would think it would kick over a bit more than what it is doing. I may end up taking the rocker cover off to see what the valves look like but I was seriously trying to avoid having to do this.

Appreciate the help guys. I'm really thinking I need to check the timing though... any ideas how to do it? It doesn't have points (or there aren't any on the bike) so no idea how to do it on a CDI bike without points heh...

 

Hmm. After some research I'm starting to wonder if there's anything I can do with the timing. The ignition advancer should be keyed, so it can only go in the one spot. Being CDI controlled, I can't see how I can actually change the timing. I'm gonna go check it now.

If timing's out, compression is the only thing remaining - which could be due to valve seating issues or a number of other things. An annoying thing to fix... hmm...

 

I cranked it over for a minute or so again. Feels like compression may be an issue somewhere.

Exhaust smells like fuel, could see a misty cloud coming out the exhaust. I took off the engine oil cap for a sniff but couldn't smell fuel there. Took all 4 spark plugs out. Don't know what you consider "wet" but I didn't think they were. Interestingly they were all covered in carbon, which just wiped off. These are brand new plugs so I'm a bit stumped.

 

No I haven't done a compression test yet but I ordered a kit so should get it done this week. Plugs didn't seem wet to me, which I found a bit strange. Yes each cylinder has good spark.

I have tried squirting fuel into each cylinder directly but it didn't make much difference.

I'm thinking a compression test may give me news I don't want to hear, but I wouldn't be surprised if the valves aren't seating properly due to carbon. Looks like the bike was running rich for quite a while the engine is probably full of it.

 

The engine's still on the bike at the moment, the bike is just shy over 30,000 kms so I can't see why it would have a cracked piston/cylinder. Cleaning out the valves seems the next logical option. I popped the head to check the timing and when 1 is TDC on the intake 2 and on the exhaust exhaust 3 are vertical, which seems to align with what the Bandit 400 manual says - so the timing is probably OK.

The compression test should tell me where the problem is (I'm doubtful every cylinder would be a problem) then it's a process of elimination to see what has happened in that area.

I'm hoping it's just carbonated valves. I do vaguely recall hearing a slight hiss when I was cranking it but didn't think too much of it at the time. But then again it could just be the pressure relieving after the power stroke.

Getting it running will be good, then I know where it stands. The amount I've learned by going over this bike I may end up keeping it longer term than I had planned - at least I know what I'm looking at!

 

Here's a vid of what it is doing. May be a bit hard to hear. Even when I put in fuel into the plug holes it didn't make much difference. It does cough a bit now and then but nothing serious.

 

I always hold the clutch in - just a habit of mine. In this case it's definitely in neutral.

I also thought about a push start. I am doubtful it will go, but I guess no harm in trying. I may wait until I do the compression test first though. Also on my agenda is that side stand switch in case it's faulty and the cause of all my problems. Wouldn't that be embarrassing haha

Doesn't it sound "weak" to you guys? in terms of the "put put" sound going along with the starter? I'm used to something that packs a bit more punch but perhaps this is normal for a little 250 motor...?

 

Ok so.. good news and bad news.

Good news is I got my $26 universal compression test kit today. Yay!

Bad news is closure is a bitch.

All four cylinders are well... very far out of spec. I am surprised to see that as I would have thought compression would be lost across a cylinder or two rather than all four of them. But (hopefully) this may be due to consistently carbonated valves... guess I'll have to dig deeper to find out.

My reference is here:

http://www1.synapse.ne.jp/s-hara/bandit/ban-spece.html

My readings are (dry) #1 at 125 PSI, #2 at 125 PSI, #3 at 100 PSI and #4 at 100 PSI.

So the link has the units in kg/cm2 which is easily converted (I'm lazy so online converter it is) and to be in spec I should have between 163 and 192 PSI on each cylinder, with a difference of less than 28 PSI across cylinders.

Well at least I got the last bit, right...?

The one that probably holds the biggest piece of information is the "use limit" spec of 113 PSI. That probably explains why the damn thing won't start, 2 cylinders have lost so much compression they wouldn't even be near working.

So... I'm torn about what to do next. Rebuilding the engine isn't outside of my capabilities (learn as you go after all) but I really did not want to have to go that far. I think next should probably be a leak test of some sort, I need to know why it's lost compression to see how far the rabbit hole goes. Unless anyone else has ideas on how I can tell myself. I'm really hoping it's just the valves, but I'm not holding my breath.

I'd be more willing if it wasn't an imported bike and didn't have to deal with wreckers that will try to milk me dry.