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Topics - Jimr1999

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Tech Forum / CDI ignition
« on: 30 Sep 22, 11:42 am »
Morning all, and here I go again experimenting.

This is a winter project for me on the engine.
The aim is to widen the power band of the engine by having self advancing timing as the revs build, Like most motor vehicles.
Peak power should not be effected as our engines are designed stock to only produce peak power at about 3500 revs.
Quite a few people add 40 of advance by filing the key. I have not. Doing this shifts the peak power up the rev range.

with a 7:1 gearing plus TAV overdrive at 1:1, 6000 revs would give approximately 60mph!!! on a 17" wheel + tyre so our rev range for power is probably best low down, and ideally over as wide a band as possible. If I were a Kart with small wheels, filing the key would be a great advantage where I needed it as the gearing is lower. As we state 35mph as an aim for the CycleKarts, having a wide band of power around 3500 revs should be the aim.
I have come across a fellow  in Canada who is producing basic CDI kits for our engines and persuaded him to ship me one.
If it works it should put less stress on the engine, have a better fuel economy, a wider power band, wider torque band and be easy to start.

These things are quite new and the fellow is a small business trying to establish a market. It is an experiment and I may go back to stock if it doesn't work out. If I were you and you were thinking of giving it a go, I would let me spend the small amount of cash on it first and see how it works out.
Thoughts please

Tech Forum / Safe-D-Speeder planetary gear?
« on: 18 Sep 22, 09:37 am »
Morning all,
what is the group think about using this...

In line in the steering column with a pitman arm steering set up to reduce effort. It has a four to one ratio so would give about one and a half turns lock to lock.
I do not intend to use this if the Pitman arm set up is to my liking when I manage to get some track time, but it is another option other than using a rack?
The Safe-D-Speeder was a thing before variable speed drills to use with masonry bits at lower speed and higher torque.
Answers and thoughts please.

Off Topic / What can I do with this...
« on: 11 Sep 22, 12:57 pm »
So, I have acquired this. I know exactly what you are thinking, and yes it was possibly just more junk but here it is. A frame from an aluminium scaffold staging rated to 250kg, 20" wide, 61" ish hook to hook, not twisted or dinged, fairly lightweight and possibly, just possibly adaptable to chassis material. Rails are about 3" by 2".
Semi elliptical springs on the front would give me the wheelbase or there-about.

It's time to employ group think. Let your thoughts run freely please, no such thing as a bad idea, they are just starting points for improvement.

What would you do with it and where would it lead you in terms of inspiration car?

Where to get stuff / TAV clone U.K. vendor
« on: 17 Jul 22, 12:54 pm »
Noticed that Hutt imports are selling these, don't know how good they are but available and reasonable.

Tech Forum / Reverse from YouTube feed
« on: 26 Jun 22, 05:47 pm »
Got this in my feed today...
Simple reverse if you have a battery

Tech Forum / oil
« on: 22 May 22, 10:59 am »
I am in a bit of a quandary regarding the subject of oil.
 Cut price racing in Australia says this...
Yet the GX tuning store seems to recommend them.

What are your thoughts?

The post lady dropped off my rather natty Nomex brown boiler suit today, as you can see, it brings the bad boy out in me and with a shirt and a spivvy tie, you may know me as "Slippery Jim" when the effects of the Nomex kick in.  ;) :D :D

Feel free to take the Michael.

Tech Forum / Kill switch recommendations and wiring
« on: 08 May 22, 08:26 am »
Electrickery is not quite a dark art to me but I know when I need advice on it. After watching a CK video where the back of the kill switch was sparking when runnning I am asking for advice on.
1 which switch is a good un
2 Which wire it should interrupt

Any pointers welcome  :)

Tech Forum / Flexible exhaust
« on: 23 Apr 22, 07:06 am »
Has anyone had experience of this type of flexible exhaust with the Honda engine?
The flexible pipe bit, not necessarily the can...

Tech Forum / Gemini steering arm to pitman arm ratio?
« on: 20 Apr 22, 09:24 pm »
Looking at the Gemini spindles and steering arms, they measure about 105mm from king pin centre to drilled centre for tie rods.
I am in the process of working out the length of the pitman arm between steering column centre and tie rod attachment point and I think it should be 70mm . Anyone come up with vastly different figures
... Or the same ratio and have any comments as to how it works in reality?

Just been surfing YouTube and found this

Has anyone made a rack out of one of these gears, we come across so many broken ones that just get replaced, it could be a source of bits???

Tech Forum / Spring travel
« on: 26 Mar 22, 07:02 am »
Morning all,
First spannering together yesterday of the springs on the BSA 3W. As they are an utter unknown, made out of wood bed slats, and may not make it to the final assembly I put a band hinge leaf to the hub underneath, then a full spring hub to hub, then a long thin stainless steel tie/washer (2 foot rule from old ones that have gone out of standard) then another shorter spring on top - times four - like the original BSA.

Loading the front end yesterday with my 100kg frame the amount of travel was minimal, less than 25mm. After my initial experiments with the springs and loadings this has come as a bit of a surprise. I am considering losing the shorter springs to get more bounce...

What is a typical amount of deflection on cyclekart springs for a similar loading?
Is harder better for our circuits?

As always your input is valued.

Tech Forum / Pit bike SDG wheel bearing spacers
« on: 04 Mar 22, 01:55 pm »
Having just got two outwardly identical front 17" pit bike wheels and stripped the bearings out, I find that they have differing bearing spaces.
Spacer tube 1 is 53.3mm long and the wheel had no dust seals
Spacer tube 2 is 42.2mm and had dust seals.

I have the Gemini 70mm stub axles (measure just over 69mm) which would indicate that the 53.3mm one plus 2 10mm bearings would be about 4mm of tightening down.

two questions.
Q1. Is 4mm of tightening down too much (or too little)?
Q.2 The seats on the hub are deeper on the one with dust seals. I intend to get as much space between the bearings as I can for better lateral load handling, do I need to shim out the depth of the seats to stop the bearings moving or is this not an issue.
Thanks for your responses in advance,

Tech Forum / Gemini front steering arm/ axle v2 question
« on: 20 Feb 22, 01:46 pm »
I'm looking at getting the Gemini front steering arm/ axle V2 and having trawled through some of the old posts here it seems some are running 70mm x17mm axles with pit bike wheels and some are running 62mm x 17mm ones for Honda wheels. The king pin inclination is set to 16 degrees on Gemini's site.

On Gemini's website I can only see the 62mm x 17mm with 16 degrees of king pin inclination built in.

Question. Are pit bike wheels better suited?
 And if, so do Gemini make a different axle to suit them and how do you order it?
Also, is 16 degrees right for the contact patch for the wheels?
Thanks in advance

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