Hi there,

I am sorry about the basic level of this question, but would appreciate any help.

I have finally got a GSXR engine (1100WP on carbs) fitted.


Sparks
I am running the standard Ignitor unit with my own loom. The low tension circuit works (tested with bulb) and the high tension circuit works (sparks seen). So, with the spark plug outside the engine I seem to have sparks. The coils use a "wasted spark" system so 1&4 and 2&3 are paired. I am fairly confident (70%) that I have the correct pairings (i.e. I am firing on 1&4 when I should be firing on 1&4) this is based only on the wiring diagram that I have.


Fuel.
I had some fuel leaks for a while, but I have replaced some seals on the input T pieces to sort this. I have good pressure. The carbs are from a sidecar chap and I have given them a clean (with carb cleaner) but haven't done a full dismantle and rebuild. They are in good condition (from a general perspective, nothing is sloppy or loose), but haven't been used for a while. There was no idle screw when I got these, but there is now one fitted, so I don't know how to set this, so I have set it to give the butterflies very almost closed.


Engine history.
The engine came from a reputable (if such a thing exists) person on e-bay. It turns over reasonably, and with the plugs out I get nice sparks on all plugs. I think it is fine (although I can do a compression test, but at the moment it doesn't fire on anything).


Recent starting success/failures
I had been working on the sparking, and at that point turned the fuel off (no fuel in carbs). Once the sparks were sorted I tried with fuel. Initially I got nothing and then I swapped the sparks (1&4 to 2&3) and one cylinder seemed to pop a bit, but it didn't start. As it didn't start (and at that point I had a slight fuel seep and the battery wasn't tip-top) I sorted the carb T piece. Then I put it back together and with a fully charged battery and I tried again. I should point out that the temp was about 1deg C (maybe slightly colder) as I am doing this outside and it is a cool night. The result this time was condensation out of the exhaust ports (no manifold/headers) but no firing. I warmed the inlet temperature using a hot air gun and tried again with a similar result (no firing).

Then I got out the plugs and had a look. All were damp with fuel. I warmed them up and dried them off and tried again. Still no firing (at all).


From all this I am deducing that I have probably stuffed the plugs (£30) with over fueling. This may either be becuase my carbs are putting out too much fuel or that I messed it when the wiring was wrong (i.e. 1&4 swapped with 2&3).


My plan for tomorrow (when it is warmer) is to try new plugs, and use the battery from my car (to remove the worry about low voltages to the ignition).



So here are my questions:
1) what is the fool proof (I use those words with confidence) method of configuring the carbs to get sensible fueling. I suspect I am overfueling from the fuel condensation form the exhaust ports, but have no real basis for this. Where should I set the idle screw on the throttle cable, should I use the choke? And how do I investigate whether they are sticking open (they have been out of action for a couple of years) or other effects of dormancy.

2) How do I check that I have 1&4 2&3 set correctly? I have a CDI that is only approximately correct, so am not 100% of these being correct (I guess I can try it wither way around, but what do I look at to tell what should be what, in an easy way).


Any thoughts/plans would be appreciated. It seems so easy/obvious when I read Dave Walkers explanations of how he fixes problems in PPC.


Thanks,

Matt

p.s. anyone in Oxfordshire fancy a cup of tea? I'm only in Yarnton!

If you suspect the carbs are a problem (ie a fuelling problem) try squirting some Eazeestart down the trumpets and see if that gets the mojo flowing. If it does you can guarantee it's a fuelling problem. If you think you're massively over-fuelling try pulling the fuel pump fuse, turn it over and squirt the Eazeestart down the trumpet. At least that way you can't flood the plugs....

If Mr Eazeestart doesn't do anything then you can pretty much rule out a fuelling problem and go looking for ignition / spark problems. It's true that bike plugs are a bit sensitive and won't take flooding like car plugs. Some people have "resurrected" flooded plugs by baking in an oven but I've found that once they're shagged they're shagged The key is to get the engine running the give it some (gentle) rpm's. Idling for long periods of time can knacker the plugs....

I dream of idling!

The carb contains quite a lot of fuel (it contains a big old store of fuel, I know this because last time it spilled on the kitchen floor!), so removing the fuse won't be suffient.

But I very much like the idea of putting on a good (car) battery, taking off the carbs, wanging in new plugs and trying E-Z start.

That will prove/disprove my ignition quite conclusively without breaking a new set of plugs.


So, once that is sorted how do I set my fueling? I am assuming that it works.


Matt

What fuel pump are you using? What's the pressure set at? and what plugs?

I ran a highly modified WP engine in my Mallock (on Keihin Flatslides) after changing from a X-Flow. There was a certain type of competition plug that was a complete bitch for fouling, and I ended up changing to an NGK road plug. Unfortunately I can't remember what make the competition plugs were... (It was a few years ago). I also seem to remember that those platinum tipped plugs were absolutely useless.

You really need something like a Dyna 2000 ignition system (has switchable engine maps), and Dyna coils. You may be lucky and find a used set-up.

I used a Honda CBR600 (carb obviously) fuel pump.

I don't know your history, but If you've gone from a car engine installation on Webers, have you turned the pressure down? Bike carbs need 1 to 1.5 psi wheras Webers need 3 to 4psi of fuel pressure.

Also... If you're running without filters, but the carbs are jetted for use with filters, you'll have a weak mixture that will be difficult to ignite, particularly from cold. Running open exhausts just compounds the problem. You may not be over-fuelling but under fuelling.
Cheers Chris.

[Edited on 29/11/08 by Memphis Twin]

For setting the carbs I'd use a colortune. That's how I set my ST1100 carbs. Had them screwed in almost all the way (so the car was just about running) then slowly screwed out the idle screw until the combustion colour changed through the colortune window.

Sorry,

I thought I had replied already. My message must be lost in internet-space.


I am running a zx9 pump. I have standard spark plugs (from suzuki, so nothing special except the price).


I picked up some EZ start today. Warmed it in the kitchen for a while (can said 20deg). Took off the carbs, gave it a squirt and tried the engine. It fired up.

So, the wiring was correct and I was getting sparks (plugs weren't knackered).

So, I popped the carbs back on and gave a squirt of the EZ-start and then turned the key.

Damn it is loud!!!! (no manifold, no nothing). It fired up and ran at a very fast idle. I don't know how fast as the tacho doesn't work (it is from a different type of bike). I ran the engine until the net curtains started twitching and then turned off sat back and smiled.


I need to sort out the noise (I have put the standard manifold on, in the inverted fashion, i.e. snorkel mode, and it helps a bit, but not enough) before can sort out the fueling properly (and all the other bits and bobs that don't work). Then I think I will follow the instructions on carb set-up, and try a colourtune (as suggested).

Incidentally I tried to get a colourtune kit from my local car parts emporium. Gunson was bought out, and these kits are not available (according to them, I guess e-bay is the way).


I would like to say a big thank you for your comments and help. EZ-start is my new friend!

Thanks,

Matt

After years of playig with bikes and also with more recent experince with the 'Blade engine yes they are sensitive to flooding the plugs, but I don'y believe flooding the plugs mean's a new set! So in a locot way save your plug money and dry them out. Best thing is ovet the gas ring, wire brush them too if you like, them get them back in the engiene whilst they'er still warm

Mister ReMan,

You were correct. My plugs were fine.

Although I have found that you can apply sods-law to repair most things. In this case I ordered a new set of plugs first, therefore guaranteeing that the originals would be recoverable ;-)

Matt