TZR 250 wierd problem

[Gazdaman]

Ok, I can just about bump start the bike. It will start firing, I can whip the clutch in, and with full throttle it'll get to about 7k revs before dieing.

Not sure what causes it to die. The plug isn't oily enough to stop it sparking I think. The mixture may be horribly wrong, but surely it wouldn't start in the first place...

Please suggest something someone, I really want to get this running. It's a new wiring loom as I thought that might be the problem.

Could be a lack of compression, but again why would it start.

I can turn it over by hand when it's warmish, not easily, but I can. Does that indicate low compression to anyone?

It's entirely possible it has a mangled piston or a broken ring or something, I've never looked inside the head.
Also checked the reed valves, not cracked or perished or anything, although one reed on the l/h block doesn't *quite* seat properly.

Also, after running, the left exhaust was warmer than the right. The left plug is slightly oily/petrolly, and the right plug looks virginic.

Gaz

[Vin]

Its running one one cylinder obviously. If the right hand plug is dry then it points towards a carb blockage. This means a carb strip. Not too difficult. Whats the history has the bike been standing?
As a TZR owner you might be interested in a yahoo group dedicated to TZR's Good links to manuals, spares and a generally knowledgable lot.

[Gazdaman]

I have had both carbs apart before, although I agree it sounds carb related.

Although if it can get to 7k revs, I thought it should at least be able to sustain it slightly even on only 1 cylinder.

The history is it sat in a garden for a long while after being bought from a scrap yard .

Since I've had the bike I've almost completely stripped it, and documented everything at www.gaz-racing.co.uk

Gaz

[Gazdaman]

Ok, the main jets were blocked SOLID.

The petrol tank has a fairly amazing amount of shit in it. Although it all seems to be flowing fairly well. Problem?
Unblocked the jets and it started better, and propelled me, but it still dies after a short while.
It's running on both cylinders.

Any idea what'd cause it to cut out like this? It's running 230 main jets.
Watch the vid for exactly what it does. (Not sure my neighbours enjoyed the making of this video).

www.gaz-racing.co.uk/bike/TZR/TZR.wmv


*Any* suggestions appreciated, I'd really like to take this to the trackday I've got booked in 2 weeks.

Gaz

Gaz

[Kickstart]

Hi

Suspect that some of the other jets are blocked. Try cleaning some of the rest of the carbs out.

Suspect they are gummed up to hell. You might be able to get away getting it to run, and putting some REALLY strong carb cleaner additive into the fuel and give it a run. Few people have had good results with Forte fuel additive, but personally no experience of it.

Not sure if there is anything that you could use to soak the carbs in. You might be able to strip them right down and leave them soaking in some solvent (probably have to remove all the rubber components first). I would not suggest petrol as although it might do the job well it could also be a bit dangerous as it evaporates.

You can get the carbs ultrasonically cleaned, but it is not cheap (around £50 a carb).

All the best

Keith
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[Gazdaman]

Getting the rubber bits off the carb is proving a bit of a tease.

1. The pin won't budge to remove the floats, and the screw underneath the floats has rounded.

2. I found one of the chokes was stuck on. Which won't have helped obviously.

3. I gave it a healthy dose of WD40 and it's cleaned a lot of the crap off. But surprisingly the main jets weren't blocked again.

I'll do some more cleaning tomorrow and I'm going to blast the tank clean too. I think it's a fuel flow problem tbh.

It's got 230 main jets in there, which are standard, I guess it's going to need altering to suit the freer flowing airfilters and the race pipes.

There's light at the end of the tunnel!

Gaz

[Vin]

Gaz,
I couldn't get the float retaining pins out of mine either. Decided to leave it in the end. My carbs were really horrible after 8 years standing. I soaked all the bits in cellulose thinners. Please be careful as they are very flammable, narcotic and can give you dermatitis. I replaced all the jets. Pilot and mains and spent many a happy hour on the back step with a toothbrush scrapping the brown shit away.

You will definitely need to re-jet for the filters and pipes. Good luck.

Actually change the air filters as they are bloody old.

After carb cleaning my TZR went OK for a while. As posted else where by me it refused to start recently. As suggested by some on here and other mates I changed the plugs and managed to start it by holding the throttle wide and kicking away. Obviously a flooded engine. I have just cleaned the air filter, which was filthy. I am hoping this will cure my problem. I’ll keep you posted.
On the tank issue I had to change the filter inside the tank because it was completely blocked where the old petrol had been. I also washed out the tank and used a tank restoration kit. I can’t remember what it was called but I got it from a company called Frost. I was a bit worried about it because it uses a resin to coat the inside of the tank. God knows if it will last!!

It’ll be worth it when is running well. Then I have to start making it look good!!
Cheers
Vin

[gavin]

sounds like an air circuit problem in the carb. you need to take all the brass jets out of the carb and thoroughly clean them, remember to tap out the emulsion tube, clean all the holes out carefully with a toothbrush and a piece of copper wire if its really crudded up. if the air cant move through the passageways in the carb properly, the fuel wont atomise properly and it will run just as you describe.

blast the powerjet in the float bowl through with some aerosol injection system cleaner, as the hole in this jet is tiny and easily missed.

soak them and the carb body in genuine full sugar Coke for a few days, it works!

[Vin]

[gavin]

yeah ive used it, and it works. cheap cola isnt so good, and it seems to help if its fresh and fizzy.

[Vin]

And rinse the coke off with something presumably

[isoJK]

dumb that shitty yamaha and buy Honda.
____________________
Happy pimppi? with Honda

[Gazdaman]

Ok, I don't know what this is. But it was under a small plastic tube just next to the main jet. And I had to pull out the plastic tube, then unscrew this.

Should I be able to blow through it? Because if I should be able to, it's SEVERELY bunged up.

(Believe it's the pilot jet, and I really think I should be able to blow through it...)

https://www.gaz-racing.co.uk/bike/TZR/DSCI0184%20(Small).JPG

Gaz

[Vin]

Looks like the pilot jet to me. Like I said I just bought new ones as they are really difficult to clean. Might be why your bike keeps dying.

[Gazdaman]

I shall buy new ones then! I need some bigger main jets anyway.

Thanks for the help Vin!

Gaz

[Vin]

Gaz,
Does this help?
Vin

[Gazdaman]

Yes it does!

Looks like I've only had the 'main nozzle' out..

Although the main jet is clear. And the thing I have that's severely blocked is definitely the pilot jet. The pilot air jet is clear aswell.

Gaz