Jump to content

Stalling, cold down pipes, no power


craynerd
 Share

Recommended Posts

Guys, I`ve bought a ZXR400 and it was apparently stood for 9 months unused. I changed the break pads, oil, oil filter... took it to the MOT centre and it passed with flying colours. I spent the afternoon riding it around. Next day, came to start it and it just stalled and wouldn`t idle!


The bike now won`t idle, hard to start. When it does start I can rev it high but the rev counter doesnt seem to register correctly. There is no power - stick it in first gear and it will ride but the revs stay low with very little power then it sort of comes around and the revs increase but it splutters and coughs. There are 4 down pipes and the middle two get hot but the outer too are cold.


It clearly isn`t running on two cylinders but I`m just worried why this happened all of sudden after running OK the day before after sitting still for months.

Any ideas? What would you do? Obviously I need to check the spark plugs but nothing will happen now until weekend and I`d appreciate your thoughts before I start fiddling!

Chris

Link to comment
Share on other sites

check the connections to the ignition coils, you might get lucky :)

Yup, get a tester on the iffy coil to check the voltage to it, and resistances of the primary and secondary windings if wiggling the wires doesn't work.

Link to comment
Share on other sites

Hi guys, thanks for all the advice. I am a bike beginner and so I've done what I wanted to attempt to do before coming on here and asking for more advice.


So I've changed the spark plugs and replaced the air filter. I also purchased second hand coil off eBay but bizzarly the cap didn't fit despite being off the same bike - the cap was longer and had a wider rubber plug at the top. Consequently, I've switched the coil and plugs but have the same caps and lead.


It was a hell of a mission to get it going this morning, but I think the battery was low which didn't help, I ended up bump starting it. It coughed and spluttered but came to life. Drove it around the block a good few times and it was much better - once at temperature it was idling ok but it was still bumping and coughing in lower gears, 1st 2nd. All my power was back but it just felt it wasn't idling smoothly. I even had a backfire with quite a bit of popping and bumping going on in the engine. Certainly wasn't a smooth enjoyable ride, felt like cutting out at any second but it didn't. Once it was home and hot it idled just fine in neutral.


Does it sound like carbs or something else still?? I admit, it scares me to death just looking at them!!


One random question. When pulling the fuel tank on and off I had a hell of a job! I presumed the fuel knob thingy, off, on reserve, would lock the fuel from coming out but it doesn't! It the valve broke or do I need to do something else?


I'll start from cold in another hour and report back but any thoughts welcome!

Link to comment
Share on other sites

Has the bike got standard exhausts on it......and what condition are the downpipes?.......any leaks on the exhaust system can cause poor running.......and some aftermarket cans can cause popping and banging.....especially on the overrun...... :wink:

Link to comment
Share on other sites

What did the sparkplugs look like?

For the sake of £15 id buy new ones and gap them.

.


I have fitted new ones!

NGK Iridium IX CR9EIX 3521

 

Has the bike got standard exhausts on it......and what condition are the downpipes?.......any leaks on the exhaust system can cause poor running.......and some aftermarket cans can cause popping and banging.....especially on the overrun...... :wink:

 

No it hasn't and the down pipes are shot and there is a hole in it ... I'm sorry, I've only noticed after reading your message but I didn't realise this would effect things on the other side of the engine but stupid of me. The guy I got the bike off actually gave me a set of good condition used down pipes to fit but it looks a big job - this was obviously a known issue! I guess I better get around to fitting them!


Chris

Link to comment
Share on other sites

That dosnt help then lol.

You can get away with bigger gaps on irridum plugs then what the book suggests.

You got any feeler gauges?


Just put some in a ducati.

Iirc the book was 0.024. Run like a dog. Gapped at 0.035 and now it runs sweet

Link to comment
Share on other sites

Have they got warmer with a plug change?

Holes arnt a good thing because a N/A engine needs a bit of back pressure to work right.

Pops and bangs is unburnt fuel.

If your taking them out to re gap them dont prise on the electrode. Iridum is very brittel.

Id start at 0.010 more then the book, see if its better.

Link to comment
Share on other sites

Set the plug gaps to the manufacturer specs do no open them up more or close them up!


Cockercas whoever told you that you can open them up more is talking shite just because it's worked on a ducati before doesn't mean it's right!

Link to comment
Share on other sites

http://www.ngksparkplugs.com/tech_suppo ... p?mode=nml

 

Another consideration that should be taken into account is the extent of any modifications that you may have made to the engine. As an example, when you raise compression or add forced induction (a turbo system, nitrous or supercharger kit) you must reduce the gap (about .004" for every 50 hp you add). However, when you add a high power ignition system (such as those offered by MSD, Crane, Nology) you can open the gap from .002-.005".

 

I think these guys know best and I doubt it he is running a supercharger or high power ignition


Keep it within specs

Link to comment
Share on other sites

Well I've been using the bike on and off all day. I filled the tank with a little more petrol and did some miles and it has run in a lot. It starts first time, even after being left a few hours and seems to idle ok. I think adding the new fuel helped. I've listened a lot to the bike and the pops do seem to be from the hole in the exhaust so like you said, next step is replacing the down pipes.......which looks like a hell of a job!!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Sign up now

    Registration is quick and easy 

×
×
  • Create New...

Important Information

Terms of Use Privacy Policy Guidelines We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Please Sign In or Sign Up