Topic: Hush's latest quizz

[Hush]

I'm working on my partner's GSX400 and finally got the timing and tuning right but find they were the easy parts.
I had a problem with the starter motor turning fast but the main motor only sluggishly, this turns out to be a major major problem.
The alternator end of the big end is badly scoured so badly that the alternator (which is part of the starter motor gearing as well) wont stay attached and slips causing the main engine not to start.
Normally you would expect to see a keyway that stops this happening but someone in the Suzuki design office in the early 80's thought better.
OK I'm open to (sensible) suggestions on how to attach the alternator to the bigend so that it does not slip, note that I am not going to remove the big end and have it specially machined so a keyway fits.
Check out the photos and give me your best ideas.

[scunny]

depends how sloppy it is. locktite bearing retainer might work, or as I did to a briggs and straton motor, super glue.

[Hush]

I've considered Locktite Scunny, never considered super glue.
I wonder if there is an industrial product that holds like a limpit?

[750goes]

weld the bastard on..

[Hush]

Sorry 750, its a sleeve tapered fit not exposed to the outside so I can't weld it.
I'm thinking a massively strong bonding agent of some sort, maybe NASA has something!

Wonder if I could use a hand grinder and cut a keyway into the shaft then drill a track in the armature?

[Don R]

We used to lock tite the flywheels on the briggs also. easier than the offset key for moving the timing around. It was also a tapered shaft but we didn't use it for the starter. Make sure the bolt isn't bottoming out, causing it to not tighten properly. maybe a star washer under the head of the bolt?

[myhondas]

Grind a flat spot on shaft and drill/tap a set screw

[Hush]

Good call on the star washer DonR and will get drastic with it like you suggest if this latest attempt fails Myhondas.

[bucky katt]

cut a keyway in the shaft and rotor?

[scunny]

another trick if the shaft etc are knackered. use some brass foil(tin foil from the kitchen may also work) wrap that around the shaft and then mount the rotor, the foil takes up the sloppiness.

[bryanj]

use valve grinding p[aste to "lap" the two surfaces until they are even gray, wash off all the grinding paste VERY carefully and then a small amount of medium grade loctite and dog the bolt up to B-Tight (Airgun if possible)

Cutting a key will not work unless the two surfaces are good it will just snap the key, believe me i had a 61 Triumph t120 that i could fit a clutch hub key in 14 minutes start to finish and bought them in 10's until i spent a whole Saturday doing it right----then it never loosened again

[Hasenkopf]

Nasa does have something, but I can't tell you what it is, as i signed a non-disclosure agreement.......

[Frankenkit]

GO-rilla glue.

[Hush]

Cheers BryanJ I have already "lapped" the shaft using valve grinding paste but it hasn't helped much.
I'm going to go with the JB Weld and add a star washer to assist the grip of the securing bolt plus Loctite the bolt thread before it goes in.

[Alan F.]

safety wire it?

[Hush]

Today I preped the shaft and alternator inner with degreaser then a soapy bath of dish wash and hot water, dried it off and now just awaiting on the postman to deliver that magic JB Weld stuff.
Got bored so cleaned out the shed, re-arranged the 4 bikes that live in there, got my sons CBR400RR running (had no gas in it  ) man that bike is soooo damn quiet but can it scream when you twist the throttle.

[bryanj]

Only other thing i can think of is that the bolt is bottoming on the thread or hitting the plain shank part before tightening the rotor up onto the taper, washer under head should fix that, also check that nothing is stopping the rotor/starter gear assembly going far enough on to catch the taper properly, if taper is good and bolt done up kin tight it simply should not spin!

[Hush]

This has been an ongoing problem since we got the bike Bryan, I think the PO rebuilt the motor but failed to tourque that bolt on.
The shaft was well scoured the first time we found the alternator loose, since then it's been a battle to keep it on.
Who builds a system like that without a bloody keyway anyhow?

Mind you it is only a problem at start up and without a kickstarter it happens all the time, at some stage in the early 80's the Japanese saw kickers as superfluous.....dang them.

[Hush]

OK the magic JB Weld has arrived, if it's as good as the blurb on the packet it is the best thing since sliced bread.

[Hush]

Damn that stuff sticks!
I coated the shaft with the mixture and painted the inside of the alternator rotor before reassembling it all again and retourquing the end bolt on adding Locktite to the thread.
Then about 6 hours later I had this terrible thought that it may have squished out the back and set the starter motor clutch hard as rock!
Yup sure enough it had grabbed the clutch sprocket but I managed to free it up so here's hoping it all works when I fire it up this afternoon (giving the JB Weld a full 18 hours to set).
I put Jaffa's bike all back together and gassed it up, if it fires up brilliant if not I'll shoot it.

[Frankenkit]

shoot it a couple times. One shot mighta done it before, but now that you've JB welded it, one shot might only piss it off.

[Hush]

Ahh damn it caught fire, I seem to have the Devils touch these days with vehicles.
I pressed the starter and smoke poured out from under the seat, an earth wire has fried all the way through the loom.
I'm guessing the JBWeld has caught the clutch sprocket again, or it could be totally unrelated event.
Anyhow I'm being press-ganged into going down to Otaki to visit with Jaffa's elderly parents for 2 days, it will all have to await my return on Monday damn it all.

[Hush]

The JB Weld has certainly cured the slipping problem but it still wont fire up!
I think I've killed it, fiddled it to death.
Am on the brink of doing the unthinkable and sending it to the motorcycle mechanic!

[bryanj]

OK mate, as an ex mechanic this is what i would do:-

(1) Check compressions with gauge, at same time have plugs resting on head to make sure of decent spark.

NB:-  use kickstart with throttle wide open and choke off and same number of kicks for each side observing not just the final figure but the steps on the way

(2) check that static timing of spark and points gap are spot on

(3) depending on results of (1) check and adjust tappets

(4) If all that checks out turn off gas tap,drain carbs and pour a small amount of petrol down each plug hole and with the throttle wide open and choke off see if it will cough--if it does the carbs aint right

[Hush]

Hi Bryan, it's more a case of slow turning of the motor by the starter, not sure if it is battery/starter related or if the bike is trying to seize?
It's like the starter hasn't got enough throw to spin the motor up or the battery isn't supplying enough oomph to spin the starter motor up!
I'm using the bikes own battery and when that fails I jumper lead it from a car battery, this morning I might try a new car battery and run the cables direct to the bike's frame for earth and the starter motor live for the positive.
It turns over fine with the plugs removed.....I'm still not quite sure what that means to me, is there too much compression? or is the starter circuit not strong enough to spin it up with the plugs in?

Additional: Being a 1982 it has no kick starter!