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Starter motor - going bang / kick back when trying to start 1230


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The mod for the 1072 is to use the 1135 starter gear. I assume you have an 1135 engine bored out to 1230? If you have a 1072 bottom end that is the mod.

If you have an 1135 bottom end I would take a look at your starter clutch, your starter motor and if you are using a smaller battery under the seat  check  the cold cranking amps output and make sure it has enough.

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And the ignition mod is to put a seperate switch in the power feed to the spark box / coils so you can spin the engine without sparks then once spinning, hit the switch and light it up. An engine will generally appreciate not cranking against spark induced cylinder pressure - hence the kick back if anything is weak!

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The "kick back" is the engine backfiring, turning the opposite direction and so hammering the starter clutch and starter motor.

Holding off the ignition from producing sparks untill the crank is actually spinning - like the mod Gixer1460 is talking about- is one way to tackle this problem, altering the ignition advance at very low rpm is another.

Before aftermarket ignition systems became affordable, some drag racers used to modify the signal generator plate on the LH side of the crank so it could be rotated a few degrees via a lever. This setting would decrease the stock advance momentarily making the engine less susceptible to backfiring.

The EFE has an electronically controlled advance, but the mechanical advancer on the earlier engines can be modified to alter the angle of the advance (or so some people have reported) and would not need a signal generator rotation setup.

Thesedays aftermarket iginition systems have become available that offer adjustable igintion timing curves solving also the kick back issue. Of course these are always more expensive then a simple separate ignition switch like Gixer1460 suggests though.

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Thanks for the info, yes 1135 engine / bottom end.

I have a standard ignition, would a Dynatek unit fix the issue?

As its a Katana I might do the ignition wire mod and hook it up to one the the buttons on the side panel. Also work as a ani-theft device. Push the button and no spark, get the motor spinning and hit the button.

 

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22 hours ago, Dukeman said:

I have a standard ignition, would a Dynatek unit fix the issue?

It might. I have an early Dyna 2000 system on my 1327 EFE. This unit has 5 preset advance curves and the curves designed for 4 valve engines have an initial advance of just 5 deg. before going up to 15 deg. at around tickover. So this helps a lot with preventing the engine backfiring at startup. I believe the later Dyna 2000i units were/are fully programmable. They are costly however and have a bad reputation for breaking down (early batch of the 2000i version I think).

Obviously a single switch for engaging the ignition separately seems like a much better deal if you're only looking to solve the kick back issue than forking out for Dyna 2000 system. Beside Dynatek there are other iginition suppliers too, like Ignitech, if you do want to fit an aftermarket ignition system.

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On 7/22/2018 at 6:04 AM, arnout said:

The EFE has an electronically controlled advance, but the mechanical advancer on the earlier engines can be modified to alter the angle of the advance (or so some people have reported) and would not need a signal generator rotation setup. 

Yep, grind the red bit off and it has less advance when it's on the starter - as soon as the thing is firing and spinning at tickover, it's off the stops - gives you a few extra degrees of retard at the start. Max advance is unchanged.

advancer2.jpg

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15 hours ago, CockneyRick said:

Similar issue with the bored GS1100E. 

I did all the Starter clutch fixes as recommended, but i fear it has probably damaged it again.

Not sure what i can do with mine as it's running a Dyna S?

The Dyna S uses the original mechanical advance mechanism doesn't it? You can do as per what I did.

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8 hours ago, Gammaboy said:

The Dyna S uses the original mechanical advance mechanism doesn't it? You can do as per what I did.

Of course it does, i swear the Alzheimers is getting worse! Cheers for reminder. 

Will get it on ramp once the Drag bike is off, it & fatty need some TLC ;) 

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18 hours ago, Dukeman said:

Thanks Gammaboy, I will look in to this, my guess is not to use a 9inch grinder.

Now saying that I am correct to say I am grinding away the cam?

 

13 hours ago, Gixer1460 said:

No - the Arm NOT the cam!

This!

The arms. I used a flapper wheel in a 4" grinder, but if you've got a 9" flapper wheel, go for it. You basically grind the stepped bit down flush with the rest of the curve of the cam (ie the red bit gets removed)

Here's a photo without the red so you can see the shape of the bob weight:

advancer.jpg.b5b673a36684d5e116cc82abaefc584c.jpg

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