First Outing on my KZ750 LTD

After weeks of waiting, I finally managed to get my 1982 KZ750 LTD tagged and insured. So this past weekend, I decided to get her off my neighborhood roads and test her on the highway.

Day 1:
Saturday started on a good note. I took the ol' girl to the gas station for her first fill-up; a short 10 minute run. Next was to my local Kawasaki place for a quick state inspection sticker. She checked out fine, so now it was time to up the ante.

I headed back down towards home...contemplating going home but the bike answered that for me when I sped past the turn. I kept going and going down the road to work just to see how she would handle on some iffy curves should I want to ride to work one day...no problem.

I continued on another 20 miles or so....not really knowing where the road was going...and didnt really care. I was just enjoying the ride. I ended up near an overpass for a major highway. I pulled into a nearby gas station for a quick snack. I called up a friend who lived in the nearby town to see if they wanted to grab lunch.

So after working up the courage, I hopped back on the bike and headed down the highway...moment of truth. To my relief, she managed to hold 70 MPH with no trouble and handled flawlessly.

After lunch, I headed back home, going down the same highway only going much further. I managed to get about 20 miles down the highway when I had an "OH SH**!!" moment. The bike started sputtering; like she was starving for fuel. I managed to get up the offramp, but as soon as I clutched, the engine died. I coasted to a stop and when to work. The tank had plenty of fuel and everything looked fine, but she just didnt wanna run. I finally set the fuel valve to PRIME for a few seconds and choked it to full. She finally fired up and sounded better. I got back home without incident, so I decided to take a little sight-seeing trip around town to see if it happened again. After an hour or so and no problems, I went back to my Kawasaki place to find some grip glue to repair my left handgrip. I told the guy what had happened and he seemed to think it was a blockage in the cap vent.

I got home and let the bike rest, but since the days ride was awesome (albeit scary as hell) I wanted to go again. So that night, I took her for a evening cruise through down. Got a bite to eat then back home...taking the scenic route before putting the ol girl up for the night.


DAY 2:
After Saturday, I was looking for any excuse to ride. So when another friend asked to meet me for lunch, I broke out the leather and lid. Bike performed flawlessly on a short highway run at 70 MPH.

After lunch, I decided to really test my bike. I went to see my dad who lives about 30 miles from me...all highway. Initially, the bike did awesome, but not suprisingly, she stalled out again; this time about 25 miles into the trip. Again, I managed to get her going again by fillinf the carbs with the prime and choke. She managed the rest of the trip with no problem.

I waited a few hours to head back on account of rain. I managed the entire highway leg without a problem. I was passing through another town and stopped at a red light. I opened the fuel cap to see if that was the issue. Sadly, a few miles down the road, she stalled out again. Again, prime and choke got her going again and I got her home safe and sound.

All in all, the bike did well and handled traffic and highway better than i expected. Im sure that the stalling problem is a small blockage and an easy fix. The inside of the tank is pretty rusty so it may be the strainer in the petcock.

All in all, the bike is well worth the money I paid for her.

Congrats! Clean out that fuel tank - there's a document posted on here about using an acid solution available from the hardware store to clean out the tank - worked well for me.

This was what I did:

kzrider.com/forum/6-paint-a-bodywork/387...ing-rusty-fuel-tank/

This is what I loosely followed:

kzrider.com/filebase/doc_download/248-ho...an-a-rusty-fuel-tank

Sounds like fuel starvation resulting from a clogged vent in the fuel tank cap.

Could ride with the cap ajar (which assures venting) to see whether it makes a difference.

Good Fortune!

I had that problem with my 83 KZ750 L3... I had a lot of rust inside the tank that would clog up the in-tank strainer. It took cleaning out the tank with old nuts (shaking the empty tank with about 30 nuts...) Then I used a rust remover solution, and then creamed the inside of the tank to prevent future rust. I also added an in-line fuel filter... It works great now.
Best of luck.
you may want to clean your carbs too... They may be partially clogged from rust.

I've had a similar thing occur to me after 40 minute highway runs. Though mine wasn't sputtering, it would die at the end of an offramp. It seemed to me that it had some problem with the vacuum petcock (ON position), since it never occurred when I ran highway in the PRIME position. I did inspect and replace the diaphragm in trying to fix it but the old one was fine and it didn't fix it.

It also had stalled a couple of times during long lights with it in the ON position.

I've always been a bit leery of small inline fuel filters, as somehow they really clog up quickly. They look fine but then they just magically stop working. Crystals or something.

Im fairly certain the problem stems from the tank. I noticed it is fairly rusty, so tonight I plan on popping the tank off and flushing it with grout cleaner and chain and shake out the strainer. Hopefully whatevers blockin my fuel flow will be gone with that.

Thanks to DoubleDub for the link

Use this procedure for rust removal on your gas tank:

Oxalic Acid Rust Removal On Gas Tanks(Found On the internet at www.wgcarbs.com )

Just ordered a few pounds of it this morning, it "should" remove the rust in my Kaw tank and it's great for removing rust on shop tools or whatever too.

I used this stuff while I lived in Florida where the humidity usually averaged 100% and it saved me a lot of labor ... it's Eco friendly too. Our humidity here in Alabama is just about as bad as on the gulf coast ... so even if it won't completely clean the tank rust out ... and I truly believe it will ... I can make good use of it

Don't know why I didn't think about it sooner, mixes with tap water, flushes out easy, it won't harm paint, plastics, aluminum or anything of that nature ... just kills the rust and leaves the metal coated to help prevent future rusting.

The guy's name is Gregg and he has a ebay store but you can buy directly from him, send payment by check or paypal. I talked to him yesterday and told him there would probably be more folks from the forum inquiring about it. He said to have whoever calls or emails to remind him they're from the forum.

It sells for $4 a pound and he can fit 4 pounds into a flat rate priority mail package and ship it for $4.95. So 4 pounds should go along way since it can be used over and over again. $20.95 for 4 pounds shipped isn't bad at all in my opinion. The only way he's making any profit on it is by buying LARGE quantities and selling small.
I'm probably going to set up a large vat to soak tanks and tools in.
This stuff will eventually turn black after heavy use but it still cleans good and washes clean with tap water.
He claims he's had several people use it for cleaning rusty tanks with great results and I know I had good luck with it before too, just never used any on a tank ... but will soon.

Here's his info: Best to try his cell first.

Gregg MacEllven
Sea Shield Marine Products (sales rep)
Mac's Pacs; teak/mahog plugs, flax, oxalic, etc.
macspacs@sbcglobal.net
310-547-2687 (home)
310-547-2606 (fax)
310-721-9667 (cell)

Late yesterday afternoon I mixed up a batch and put it inside my original KZ tank.
The tank had what I would call a medium overall surface rust throughout the inside and a fairly heavy rust build up along the entire bottom surface.

The instructions suggest warm water but I talked with Gregg and he said it wouldn't really matter as long as I wasn't looking for INSTANT results and let it soak so I used unheated water from the hose and about 8 heaping tablespoons of Oxalic acid and let it soak for 24 hours.

I just drained the tank and the water was colored kind of a light brown, I flushed the tank with clean water twice and looked inside as far as I could see with a strong miniature LED flashlight and NO RUST was present ANYWHERE including the bottom surfaces.
The Oxalic acid left behind a off white colored protective coating on the metal surface just like Gregg said it would

Once I got the tank dry I saturated a shop rag with gas and rubbed the white coating with it and the coating stayed put.

But ... I will highly recommend you folks give this stuff a try because it sure takes the work out of removing rust from our gas tanks and it did not faze the paint either where I overfilled it.

This old tank will get repainted and used now that the rust is gone ... but for you folks that have internal surface rust on tanks that still have good paint on them, don't worry ... this is the ticket right here !

I can tell you right now that it works very well, the tanks I cleaned back in November have sat in my shop until I decided to tag & drive my 78 KZ a few days ago.

I looked at all 3 tanks & they still looked rust free inside other than a small haze which may be simply what the metal looks like after sitting so long after being treated. I thru a 1/2 gallon of gas in it, sloshed it around, poured it out, installed the tank with clear gas line & the fuel runs out CLEAN ... no rust deposit showing up in the filter either !

Oxalic acid WORKS better than anything I've ever tried in 30 years of wrenching. Use hot water, mix it up double or triple strength, fill the tank to the rim and let it sit overnight. If you don't get the results you want, do it again, this stuff is cheap and WILL clean the rust out of tanks without harming the paint even.

I kept several gallons of used mix in a large plastic container & constantly throw stuff in it like a set of rusted boat trailer wheels, impact sockets etc. & it cleans them like new, may take a while but it works.


Some tanks may require more acid to do the job but this stuff is cheap & easy to use, won't even burn the grass when poured out.

I did a Honda tank for a buddy that had some ridiculous rust along the inside bottom flat areas & top part of the hump. I tripled the recipe & let it sit a couple of days and it came out CLEAN.

Would rather NOT use a tank liner product that may or may not peel away ... oxolic axid won't hurt the paint either, so that's a huge plus.

Thanks MFolks. Ill have to give it a try.

I took the tank off and noticed the fuel line from the prime spiggot on the valve had what appeard to be a BENT plastic in-line fuel filer.

I flushed the tank with muratic acid last night about three times using a 2-foot length of chain. (baaaaad juju that stuff)

After the first round, the rust that came out was unbelievable, but there was still quite a bit left in the tank. So I gave it two more rounds, rinsed out with water then again with alcohol, WD-40. Let it drain/dry then rinsed with gas. The gas that drained out was nice and clean.

When it gets too cold to ride, Ill probably take her to a friend of mine whos a bike mechanic and get the carbs cleaned and dipped. as for now, I think she'll be ready to make an entrance for Thanksgiving.

One other thing to watch is the petcock. If you have to original vacuum petcock, you could experience some of the issues I had with my '82 750 Ltd. Routing the vacuum line is a little tricky to keep from kinking the line, but I especially had problems sometimes if the line got hot and softened up enough to practically crimp the line, closing the petcock.

Just had to make sure I routed the vacuum line to mimimize that possibility.

Good luck! Loved my 750 when I had it.