Can't Get 72 Kawi F6 To Start

[KawiF6Rider]

Just got a 1972 Kawi 125 F 6 two-stroke dual purpose bike for free. They claim they had it running last fall. It's got over 5000 miles on it. Only numbers we found on it were F6-24154. It was made on 10-1971. We've got spark, fuel, but can't seem to get it to start. Used carb cleaner to no avail. She sputtered once for a sec or two but no more now. New gas. What should I do now? It's got an electric start on it but I've got no battery for it so I'm just kickin it right now and it's startin to hurt. Thanks for any help guys. :worship:

 

[reelrazor]

F-6? Is that thing rotary valved? A lot of the old Kawi's were. The carb will be under a plate on the side of the engine if it is.

If so, the rotary valve may be munched. The rotary valve is akin to reed valves in that it allows fuel in as a timed event and seals the crankcase with eth charge trapped in it so the transfers can pump it into the combustion chamber.

..."She sputtered once for a sec or two but no more now".......

Did you replace the plug and try it? What did the old plug look and smell like?

...."New gas"

Was it new when you started trying to get it to run? Did you drain the bowl of the old gas? Did you drain the tank entirely?

 

[KawiF6Rider]

The guys who had it running last fall replaced the plug and it's in good condition. I've got really good spark. Really bright blue almost white. Again, last year they claimed they drained the tank and put in new gas. I emptied the tank this morning after takin the petcock off to clean it. I did add some fresh gas last night as I was trying to get it to start. Yes this F6 is a rotory valve engine. This morning my brother pulled me around the yard with his quad. It would run when I had it in gear and moving of course, and when I pulled the clutch lever it would run only for a little bit then it would die. But when I gave it throttle it almost instaneously killed it. Any more information on how to adjust the rotory valve or anything else would be greatly appreciated. I got this bike for free and I know if I get it running it would be really fun. I'm gonna pick up a battery for it today hopefully and see if it starts that way. Thanks, Bryce

 

[reelrazor]

No adjustment on the rotary valve. It is a disc with a timed hole/slot cut in it and it is keyed onto the crankshaft and can only be in one position. They are either good or bad. The factory R.V. was steel and when they would go they would tear some **** up. When this happened people replaced them with fiber valves and had the case surface machined. The fiber valves can slowly degrade and basically disappear(from the outer edge in). This causes the engine to run like crap for a while then not run.(it will try, or run but so poorly you can't ride it). You can check it by removing the carb from its' boot, remove the plug and roll the engine over slowly while watching the valve turn. If it is good, you will see the side of the disc(valve) and it will have a cut-out in it for part of its' circumference that looks machine made(not raggedy or bent up).

I think you should check it just for peace of mind, but your real issue is in the carb. Clean it, clean it well. If you haven't done that before, have someone who has(verifiably) show you how.

 

[KawiF6Rider]

Alrighty I'll do that. I've also noticed a rattling sound while trying to kick it over. I've taken the ignition timing cover off and found out that the crankshaft nut has come loose alittle and has stripped the threads from the nut, luckily not the crank itself. I had plenty of spark last night and now I've got none at all. So I cleaned the points real well and my dad (who is a tool and die machinist) is going to get me a new nut and a die to clean the crank threads before I install the new nut. There's a little timing tooth that sticks out of the crankcase and there's another timing mark on the balancer that I pulled (flywheel?) and my question is, how do I adjust the spark timing? I'm thinking I align those marks and tighten the nut down. Please let me know. I'm going to have my grandfather who's an automotive mechanic help me clean the carb cause I bet it needs cleaned. I took the carb cover off and it looks really nice and clean, but looks are most likely deceiving with carbs. Also, where can I get replacement parts for this bike? Like a carb kit and R.V.'s. Thanks again for everything.

 

[reelrazor]

Check to make sure the flywheel key didn't shear. It aligns the flywheel(what you are calling 'the balancer') and the crank. It is usually a woodruff key. If teh flywheel nut was loose, the key has likely sheared. You will often still have good spark but not even close to 'on time spark' when this happens.

Check that before you go to playing with timing, you may have just found the real problem.
Get back to here and let me(us) know what you found before you mess with the timing otherwise.

 

[reelrazor]

Ohh and I doubt if any of the old skool aftermarket companies who used to make replacement disc valves still do. You might want to check with some vintage mx bike sites on that.

Otherwise, it is OEM Kawasaki.

Carb kits can be had from the carb manufacturor's distributor (Sudco/Mikuni USA in the case of a Mikuni carb, which your old kawi likely has-google sudco).

 

[KawiF6Rider]

Yes it has sheared the flywheel wooodruf key. The pieces were stuck to the flywheel through it's magnetic properties. I used electrical cleaner spray to clean the points and the coils so they are in good shape. But yes it has sheared the woodruf key. What now?

 

[dirt bike dave]

Replace the woodruff key and start up that bad boy! If you have difficulty finding an OEM replacement, you can make a key by cutting a slice off of a properly sized washer.

Perhaps you have a local hardware store or motorcycle shop that has an assortment of keys from which to choose.

When reassembling the flywheel onto the crank, you want a tight fit with lots of friction, so don't put any grease on the mating surfaces.

 

[KawiF6Rider]

Alrighty I've got plenty of washers to screw around with so I'll try that tomorrow night. Also, I've been having trouble locating a carb rebuild kit for my F6. I didn't see any stamping on the carb as to what kind it is. I think Mikuni? I would like to find a carb rebuild kit so I can get it running really good. I've got the title so I may get my motorcycle license and register it to run back and forth to school with. It needs a new brake light cover cause it's busted out and some turn signals. Any idea whereas to get the replacement brake light cover? Thanks again to everybody.

 

[reelrazor]

I would try to find a real woodruff key before I used the washer route. DBD is right when he says to check with hardware stores and cycle shops and even automotive supply stores as to a woodruff key assortment. Take the pieces you found to match up. Also take the dimensions (width of the slot, depth of the slot, and you can grind one that is too long to fit, but one that is too short to fit won't work worth a crap).

Unless the float needle is bad, you should be able to clean the carb without a 'rebuild kit'.

Lay a clean rag on a bench, take the carb off the bike and take the carb apart on the bench. unscrew teh cap that holds the slide in the carb body and let teh cap and slide hang on the cable. Make sure you have a clean workspace. Have a notepad or digital cam at hand. Make notes/take shots of things to give yourself a reference.

Take the carb apart, noting where everything goes. There will be an idle adjust screw on the side of the carb body right next to the slide. Leave it alone, no air or fuel passage is affected by it. Near the downstream end of the carb body will be a small brass screw head showing, in a little recess. That is teh pilot air screw. It will have a slot for a flathead screwdriver. Turn this in(clockwise), counting how many turns it takes to reach 'bottom'(don't crank it down hard). Make a note of this(usually 1-1.5 ). It will have to be reset when re-assembling carb. Now, remove that screw all the way(counter-clockwise). It will have a taper on it. Check this taper and that it has not got a groove worn into it. There will be a spring under the screw, which will prolly stay in the recess. You need to get it out, same with the o-ring that is in there. All rubber parts should be off the carb body or they may get screwed up by the carb cleaner.
Shoot carb cleaner through all the carb passages, paying special attention to the jets(brass orifices) and to the holes in the upstream carb throat. Remove the needle jet if possible(it is the brass tube above the main jet and goes out through the top of the carb).

Dry it with compressed air if possible.

Re-assemble.

I didn't include the whole process because I got to thinking about how much typing I was doing and how many little details are critical and so I wrote what follows.

I strongly suggest you be realistic about your abilities and find someone who has experience doing this to help you, or remove the carb and have a shop clean it. It won't be all that expensive(not nearly as expensive as screwing the carb up).

 

[KawiF6Rider]

Thank you very much for that information. I will aid my grandfather in cleaning the carb so I know how to do it next time. Like I said before my dad is a tool and die machinest so if for any reason at all I cannot find a woodruf key he'll make one for me. Just for references, would anyone happen to know where I can find an exploded parts diagram of the carb on my F6? It would greatly help if my grandfather and I got stuck. Thanks guys.

 

[KawiF6Rider]

Oh and one more thing. When I do get a woodruf key, a nut to go on the crank and my carb cleaned, how do I time the spark?

 

[reelrazor]

http://www.carbparts.com/mikuni/vm20_44.gif

http://www.mikuni.com/pdf/vmmanual.pdf

http://www.geocities.com/mraxl/carb/mikuniflow.jpg

Your carb may vary in details, but most of what you need(if you do indeed have a Mikuni) will be somewhere in one of those links.

Timing? Again, too many little details to cover to type it all out. There should be marks on the flywheel(maybe an 'F' or maybe just a line) and a pointer on the engine case. With a new flywheel key and the fact that it ran before, the timing can't be too far off. I would replace the key, make sure your point gap is close(.014"-.016") and just verify that you have the timing close with a timing light. There will be slotted holes on the stator plate (the part the points are mounted to). You turn the stator plate in the direction the engine turns to retard the timing, and opposite to advance.

 

[KawiF6Rider]

Well I finally got the key, cleaned the partly stripped crankshaft and have the flywheel installed. I have no spark to the plug. So I traced wires with a test light and discovered that I do have power to the coil but none coming out of it. So my question now is, where do I get a replacement coil or is there another coil which will do the job right? Thanks guys.

 

[reelrazor]

Well I finally got the key, cleaned the partly stripped crankshaft and have the flywheel installed. I have no spark to the plug. So I traced wires with a test light and discovered that I do have power to the coil but none coming out of it. So my question now is, where do I get a replacement coil or is there another coil which will do the job right? Thanks guys.

****Okay. Don't jump to conclusions about that coil just yet. When the flywheel was loose and wobbling on the crank did it happen to grind its' inner edge into the stator windings?(they are the coils that are under the flywheel-one for ignition{primary coil/windings}, the other for lights/charging). You will have seen gouges in the flywheel's inner surface and scrapes on the stator. I fthat heppened, damn, I am sorry for you, but better to know now before you spend too much on un-necessary parts.

If the stator is intact and untouched (re) check the basics first.

The points switch the circuit through the coil 'on' and 'off'. The points are CLOSING and opening to the right spec(again .014"-.016") aren't they?

Did the wire to the points get cut by the flywheel?

etc. etc.

 

[KawiF6Rider]

Nope. My dad and I thoroughly checked over everything. We weren't getting anything but a spark here and there out of the flywheel even when we had it put back together so we took a small file and filed down the points cause they were glazed over alittle. Now we've got the good power to the coil but none out of it. The flywheel looked good no physical scrapes or anything like that. So I'm almost 100% positive that I'm ok in that field. We did check the points and they are closing and opening like they should be. So now I guess I'm lookin for a coil to replace this one. The only number on it is 461021. I'm assuming that's an old Kawi number and it's pretty much useless now but I'm tryin not to jump to conclusions. I'll be posting a pic of it in a little bit and I will reply with my website.

 

[KawiF6Rider]

Alrighty got the pic up. It's under the album 1972 Kawi F6. Check out my 4-wheeler while you're at it too. Let me know whatcha think about the coil.
http://f2.pg.photos.yahoo.com/g_force_racing_i4

 

[reelrazor]

Test the coil for continuity.(all wires off) Where the power goes in, through to the other small wire(primary side of the coil) you should have continuity. From the primary to the secondary(spark plug lead) there should be NO continuity. With wires OFF the coil and spak plug, there should be no continuity to ground through either/any connector on the coil. If any of these is wrong on yours, then yes, you have found your problem.

Ohh and, what do you mean "spark at the flywheel"..?

 

[KawiF6Rider]

Sorry I mean the spark plug. It would spark once like every 40 or 50 times I would turn the motor over. It was a very weak spark too. My dad works with an electrician so he's gonna test the coil out. I'll let ya know the results. Thanks again!

 

[KawiF6Rider]

i was unable to check the coil for continuity...what's the OHMs reading and voltage that is supposed to be running through the coil?...i'm in automotive technology vocational class and my instructor is an electricals expert so he's gonna help me out...possible find another coil that would work with my setup...thanks for any information

 

[KawiF6Rider]

Well got it running finally....it's been awhile huh?....the ignition switch has two wires that were frayed and contacting each other and wouldn't allow enough juice to coil for spark....well she started and ran just great the other night and now all of the sudden she'll run for alittle bit then eventually die and i can't do anything to keep her running....i'm thinking something to do with the float...but i also need a new spark plug for it and the one that came with it doesn't seem to be the right one....anyone have any numbers i can cross reference? thanks for anything