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8 Posts
Discussion Starter · #1 ·
Bought 1990 Kat 750 off Ebay on the very cheap. It was sitting about 1 year before I bought it.

Had keys made (she lost them over the year it was sitting)
Re-charged battery (it was dead)
Checked for spark to #1 wire (good) and plug looks good
Removed and replaced fuel in tank with good hi-octane fuel
Checked to make sure fuel line was full of gas to carbs (it is)
Choke seems to move freely in adjusting to each carb (both on and off)

Bike turns over like crazy but will not fire.
Maybe carb problems, maybe something else.

Can I spray starting fluid into each carb ( a little) to see if it will acutally start?
It was suggested by my local dealer to put a teaspoon of fuel in each plug and turn it over from there. (I have yet to try this but will later today).

Anything else I should check??? Maybe I need to clean the carbs but I do not know how.. so any thoughts on that would also be appreciated.

I bought the bike real right and could always part it out and easily make back the money, I just would rather see where this leads first.

Thank you in advance for any suggestions and detailed help.

· Registered
8 Posts
Discussion Starter · #4 ·
Pulled all the plug wires and checked and cleaned each plug. A couple of the wires were cracked (very small), and so we pulled plug wires and ignition off a 98 Kat 600 and swapped them to see if it might help. We were told to put a little gas (2 teaspoons) down each plg hole before reinstalling the plugs and wires.. so we did.
After a deep charge of the battery, clean plugs, drained and replaced all fuel, full oil change, little gas down the plugs... we have fire and lift off. Runs pretty sad, but I have added some cleaner to the gas to help clean out all the carbs. No big improvment yet, but it is getting too cold to drive for long anyway.
Will end up being a winter project.
Thank you for your interest and all suggestions.

· Registered
42 Posts
BenchFalco said:
Yeah carb cleaner is a good idea especially since it's been sitting a long time.

You can use the spray type that you spray into the engine while it's running. I used this on mine and it worked wonders. But afterward be sure to remove the plugs and clean them as all the gunk from the carbs will stick to your plugs. If there's enough gunk, it could prevent them from sparking at all.

Since it might be a winter project you could remove the carbs and do a complete cleaning and give them a little tune up as well.

Since it's been sitting it's likely old gasoline that's gelled/solidified in the carbs. The bike may just be running on a couple well performing, out of the four, while the others might be working, but not as well as they should. (a good cleaning seems necessary)

Be sure to make sure you have a clean air filter too.

Since it's runnning it's just a matter of tweaking things now. Glad to hear it has a heartbeat again!!

My bet is you have varnish (gelled gas) in the carbs blocking the idle jet, one of more of the mains, and or the needles too.

Take them down, clean them well with Carb Cleaner, squirting each and EVERY hole in the carb you can find, then blow them out with air, and re-assemble.

Katanas do foul plugs often, especially when choked too long and also after setting up (like any carburated bike).

So be sure and get another set of plugs too.

Good Luck,
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