Author Topic: TM400R Flywheel Weight (Read 7420 times)

TIKI · « **on:** May 12, 2015, 04:40:10 PM »

Hi Guy’s

Does anyone have any experience or know about the aftermarket flywheel weights on a 1971 Suzuki TM400R. I started working one and assume they thread on the stock flywheel so once the nut a lock washer are removed it should thread off counterclockwise? I want to pull everything off to replace the crank seal and clean it up. I also assume that sense the weight covers the timing marks on the flywheel the weight needs to be removed to check the timing. I have included a photo of the weight on the TM400 and one without the weight on another TM400 I have, also a photo from an old article about installing the weight as it looks very similar to my set-up. Any thoughts or input on Weight removal? Thanks

With Weight

Without Weight

Article Photo

sleepy · « **Reply #1 on:** May 12, 2015, 05:13:39 PM »

It is just screwed on but are there grub screws in those 3 little holes which lock it on to the rotor. Yes the timing marks are on the front of the rotor.

TIKI · « **Reply #2 on:** May 13, 2015, 09:44:43 AM »

Quote from: sleepy on May 12, 2015, 05:13:39 PM

but are there grub screws in those 3 little holes which lock it on to the rotor.

Man I hope not but I'll need to clean out all the rusty crap and take a look inside. if there are screws in there it's going to be a job to get them out if at all.

sleepy · « **Reply #3 on:** May 13, 2015, 11:33:51 AM »

If no screws then it would rely on a stepped washer under the main nut to stop it undoing. The 3 holes could be use to make a spaner with 3 pegs to undo the weight.

bazza · « **Reply #4 on:** May 13, 2015, 11:49:30 AM »

Thought from memory you could put on a heavier TS400 flywheel to help get rid of the razor power band??

frostype400 · « **Reply #5 on:** May 13, 2015, 12:02:53 PM »

You could put a complete ts400 ignition if you are not up to riding one stock my two are stock I might get my 74 seat done in gripper material when it launches it is so slippery on the vinyl.

Plus the vibrations you get through the bars make it hard to hold on to for an extended time especially when the front is coming up it is the only bike I have ridden that really feels dangerous and hits so hard when you give it a bit nothing for a sec then bang great fun.

I put wide pegs on my 74 I will probably do the 71 as a lounge room piece.

TIKI · « **Reply #6 on:** May 13, 2015, 04:25:23 PM »

Got the flywheel off tonight but the weight is still connected I’ll try to separate the two at some point, no screws in the 3 holes. Both the crank end nut and the threads on the flywheel look to be RH threads meaning righty tighty lefty loosey , am I correct on that? The flywheel puller for this bike is listed as 30mm x 1.5mm Right Hand Threads so why does the article I posted above say to install the weight counterclockwise?

sleepy · « **Reply #7 on:** May 13, 2015, 05:42:00 PM »

Maybe the clocks go backwards in the US!!!
You are correct ,the threads are normal right hand so to undo turn anticlock.
Good amount of rust happening there, was it underwater for a while?

TIKI · « **Reply #8 on:** May 14, 2015, 12:31:21 AM »

Not the entire bike but I can see a waterline on the weight as the case had water in it at some point.

TIKI · « **Reply #9 on:** May 15, 2015, 12:05:35 PM »

Well I’m at a loss as to how to remove this weight. I tack welded a piece of square stock to the weight so I could put it in a vise and with channel locks I cannot get the flywheel to move. Why are there 3 holes in the weight? They are about 1/8” deep but defiantly no screws in them, could there be rivets or pins in them attaching the weight to the flywheel? If so the 3 holes don’t line up with any holes in the flywheel so if they were to attach the weight to the flywheel you would need to thread the weight on drill the flywheel through the holes and drive the pins in and that doesn’t make sense. Are the part of the machining process when the weight was made? My last option is to take it to work and put a 3’ pipe wrench on it. Any thoughts here? Thanks

sleepy · « **Reply #10 on:** May 15, 2015, 12:51:45 PM »

I would think the 3 holes are for a tool with 3 pins to undo it.
By the look of the rust it will be quite hard to remove.
Don't use a pipe wrench on the flywheel may not end well.
If it won't come off leave it on and time it by other means. I can explain how or if you are close do it for you.

bazza · « **Reply #11 on:** May 15, 2015, 06:01:08 PM »

agree with sleepy, 3 holes to attach with tool to hold while tighten or loosen?
Coke to strip rust...lol

oldfart · « **Reply #12 on:** May 15, 2015, 07:09:46 PM »

I redcon it's rust welded on..... needs to sit in diesel or the like for a while to free up.
Also agree with sleepy

pokey · « **Reply #13 on:** May 15, 2015, 07:48:41 PM »

The Destructions apart from incorrectly stating to install counter clockwise also suggest using Loctite. Maybe thats what is holding it.

Loctite dissolves with acetone if you can get a bit on to that thread or soak it in acetone for awhile. ( nail polish remover has acetone just dont get busted when you pinch your wife or daughters) Loctite also softens with heat, dont damage the flywheel with too much direct heat. Dont apply heat directly after you apply acetone or bye bye eyebrows but you already knew that.

bazza · « **Reply #14 on:** May 15, 2015, 08:09:11 PM »

We also use heat at work on bike s with locktite be carefull

80-85 husky · « **Reply #15 on:** May 15, 2015, 09:39:29 PM »

razor band is apparently due to crook advance curves on tm's. ts ignition provides more stable ign curve I believe.

oldfart · « **Reply #16 on:** May 15, 2015, 09:48:04 PM »

Avoid riding them like the plague. Been there and done that.

Momus · « **Reply #17 on:** May 15, 2015, 10:35:10 PM »

Ideally you would make an aluminium split ring clamp to hold the flywheel tight in a vice and another tool to attach to the weight.

If it where my job I would drill and tap the 3 holes to M8 and make a matching bolt on flange and weld that to a 600 mm long bit of RHS or bar as the unwinder

I would then gently heat the threaded area with a welding tip oxy flame and watch for the telltale puff of smoke that comes out when you have killed the loctite- assuming there is any.

Prior to that I would have given it a good soaking with CRC.

Failing that, this:

http://www.ebay.com/itm/1971-SUZUKI-Cyclone-400-TM400-TM400R-FLYWHEEL-ROTOR-/361234746822?hash=item541b44cdc6&vxp=mtr

A new weight would be a simple job for any machinist.

TIKI · « **Reply #18 on:** May 16, 2015, 05:15:56 PM »

Thank you all for the reply’s and advice, I think at this point I will see if I can at least get it started and evaluate where I go from there. I did ride this a few years ago when I first bought it so the timing should be close as it sits. I just finished going through the carburetor which was leaking out of the overflow I tried setting the float level multiple times, tried a new needle and seat and found the brass overflow tube in the bowl had split from top to bottom. I had another float bowl which solved that issue so tomorrow I will try to fire it up.

TIKI · « **Reply #19 on:** May 18, 2015, 08:30:36 AM »

Quote from: sleepy on May 15, 2015, 12:51:45 PM

If it won't come off leave it on and time it by other means. I can explain how or if you are close do it for you.

Sleepy can you describe the timing process for me, my manual does not give a lot of detail on the process other than using a timing light but that is to check the timing while running and I am trying to get it running.

sleepy · « **Reply #20 on:** May 18, 2015, 10:46:49 AM »

I sent you a PM

Author Topic: TM400R Flywheel Weight (Read 7420 times)

oldfart

oldfart