Starting problem, thoughts anybody???

[Slingshot]

Hi all, I need some suggestions please...my bike ain't running to well

It's a 89' GSXR250R and it doesn't like starting or idling.

When I got it I had real problems when it rained, water filled up the hole that the spark plug sit in and it wouldn't start and had real problems developing power. I'm sure it was only running on three cylinders at the best of times.
I took it into the shop and they changed the spark plugs & ordered new plug caps which seems to have fixed that problem.

Now, sometimes I have to apply full throttle to get it started and at full throttle it only just runs. If you ease off a bit it stalls, eventually if I leave it struggling at full throttle it will all of a sudden burst into life. It also doesn't feel like it develops power as well now either.

I figure it could be crap in the fuel lines, problems getting the spark plug to spark or maybe unbalanced carbs (although I don't really know).

Anyone have any ideas???

[Hitcher]

Sounds entirely sub-optimal. It also sounds like plugs/spark and maybe mixture. If you're going to change things, do one thing at a time -- otherwise it will be harder to know what made the difference!

[Eddieb]

Hi Slingshot

Does it do it from cold or only while hot? If it's when hot it could be a dodgy coil. From my own experience they get a bit dodgy as they get older on the smaller suzuki's and cause the sort of thing you seem to be experiencing.
If it's all the time then maybe check both fuel and spark systems.

Eddie

[Slingshot]

Hi Slingshot

Does it do it from cold or only while hot? If it's when hot it could be a dodgy coil. From my own experience they get a bit dodgy as they get older on the smaller suzuki's and cause the sort of thing you seem to be experiencing.
If it's all the time then maybe check both fuel and spark systems.

Eddie

It does it from both hot and cold. I went over the Taka's last weekend and stopped at the top for a smoke, it was most embarrising trying to get it to start again
How do you alter the mixture???

[Yamahamaman]

I had a similar problem with a Kawasaki ZZR400 I once owned. Turned out to be a dodgy battery. Just did not have enough grunt to turn the engine over and provide the necessary current for the high tension.

[MrMelon]

This is exactly what was happening with my tzr when it was leaking coolant into one of the cylinders via a blown gasket,and fouling one of the plugs :/

Do you know what cylinder it's doing it on?
Take the plugs out and take a look at them, and if there's one that's covered in oil and crap, try replacing it and see if it sorts it out.

[Motoracer]

I know this doesn't help but when my 88 GSXR-250, I took it to the shop a few times, spent about 700 then got rid of the bitch when the problem just kept comming back! I hope your problem gets sorted out for good without costing too much.

In my opinion, I think it could be worn out needels on your carbs.

[Slingshot]

Thanks for the suggestions everyone, come thursday this week I'll be the proud owner of a double garage (oh and a house), so I'm looking forward having a bit of a tinker.

This morning it fired into life straight away, I applied a little choke to get the revs up a little then proceeded to kit up. After about 2 mintues of running on the choke the rev dropped off and it stalled
Then trying to start it I had the same old full throttle/barely running problem, I held the throttle at full open and after about a minute it all of a sudden fired into life again.
Hopefully my limited mechnical skills will be able to solve the problem.

Any further suggestions are most welcome.

[Slingshot]

I've just had a mate a work have a look at my bike. We've discovered at least one of the carbs is pissing out fuel when the bike was started (this explains the smell of fuel).
His thoughts are that one or more of the carb floats is sticking and that all I need to do is pull the carbs of and give them a good clean.

Thanks for the replies, I'll keep you all posted as to how I get on.

[Dave]

The symptoms you describe are flooding. The needle valve in the float will have some shit under it. What you can do is reach across under the floatbowl on the carbs with a long thin flatblade screw driver and undo the drain screws on the bowls. Let the fuel run through for a minute and then tighten the screws. That should flush any rubbish from under the seats and fix your problem.if it still does it, you'll have to get the carbs stripped and cleaned

[Slingshot]

Update: Last week I took the carbs off my bike, in the weekend I finally got a chance to strip them down and clean them out.

I used CRC Carb R Cleaner which seemed to do a pretty good job.
Basically all I did was took the float bowls & floats off each carb then took the diaphragm covers and diaphragm slides off. I left the jets in (cause I tried to get one out and it didn't want to come) and sprayed the CRC through them, the combination of the cleaner itself and the pressure that it came out of the can at cleaned them well. I then proceeded to spray everywhere I could. I reassembled everything the put the bike back together.

The bike is now running pretty good, except it tends to hold back a bit (feels like it's out of fuel) but as soon as I change the fuel tap to Prime it goes fine, so I think there must be a kink in the fuel pressure line, I'm gonna take the tank off again tonight and fix this up.

The morale of the story is that cleaning out your carbs is actually fairly easy. My only advise is when dismantling the carbs, take your time and do one at a time so if you forget how they go back together you can look at one of the others.

Photos of the carbs

[riffer]

The morale of the story is that cleaning out your carbs is actually fairly easy.

Hmmm. I guess I might add this to the list of things to check on my bike too. Glad to hear it worked out good mate.

How did you go with balancing the carbs afterwards? Did you do this or was it unnecessary?

[Slingshot]

I didn't touch the mixture screws at all, I didn't want the headache of having to re-balance them.

[alan_w]

When I bought my '89 GSXR250R Slingshot it had awesome problems with the bike not running below 8k rpm at all, acting like it was constantly flooded.

After finding the choke cable seized wide open (I couldn't believe this!), lowering the float levels, balancing the carbs, and lowering the needles slightly it has worked nicely.

However recently it's been on a race stand for six weeks, during which time I've advanced the ignition 3.5 degrees and drilled two 8mm holes in the can's rear baffle. Now it bogs down if the throttle is opened further than about 1/2 way. I'm hoping its just stale fuel in the bowls and that taking it for a good long ride will fix this.

Also Slingshot, I've sent you a pm.

Thanx
Alan

[mccool]

Slingshot, it might be worth cleaning out the petrol tank while you are at it. If the carbs had cwap in them the fuel tap could also be partly blocked. Method = when there is not much petrol in the tank take it off without shaking it around too much. Remove the fuel tap (usually 2 screws) and empty the petrol through that hole, not the filler cap, into a sturdy container. Be amazed at the amount of paints flakes, animal bones, small packets of white powder, and general gunk that spills out. If necessary, carefully clean the gauze filter on the fuel tap.

Another easy thing to check - are the HT leads securely jammed into the suppressor caps that jam onto the spark plugs? If someone has been pulling the caps of by the leads you can end up with a dodgy circuit there.

If all this is stating the bleedin' obvious, telling you to suck eggs etc, I'm sorry.

Seeya
Larry