Is a 920 kit worth it?

My twin 32mm JSmotorsport flatslides:

1) start first kick

2) idle like a rock

3) NEVER need synching, never need balancing, continue to be zero "maintainence" for 18 months now.

4) I had a single Mikuni before. There was no tradeoff, no compromise.

All I did was gain gain gain. Gain in power at low end, mid range, and top end.

I will never, ever, consider running a single carb set up now that I have experience first hand the benefits of a really good twin carb set up, and these flat slides are fabulous, an astounding improvement over a single carb.

1up3down said:

My twin 32mm JSmotorsport flatslides:

1) start first kick

2) idle like a rock

3) NEVER need synching, never need balancing, continue to be zero "maintainence" for 18 months now.

4) I had a single Mikuni before. There was no tradeoff, no compromise.

All I did was gain gain gain. Gain in power at low end, mid range, and top end.

I will never, ever, consider running a single carb set up now that I have experience first hand the benefits of a really good twin carb set up, and these flat slides are fabulous, an astounding improvement over a single carb.

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Great, thanks chaps, that's a good endorsement! Zero maintenance and gain, gain , gain is always good! Do you have a link for these wonderous devices?

Here's the link for the carbs. Also, why order the tuning book through the Victory link when you can order direct from the author? Same price but why add a middleman unless I'm missing something.


http://www.jsmotorsport.com/

ugh, I got my copy from Jim direct but in my haste over looked the Victory site source.

I'm still trying to come to grips on 920 extra torque w/o any extra rpms. Less shifting for one thing but maybe extra easy to trip out too.

crusader sports wrote;

Dare I ask what the Steve Maney barrels and pistons cost?

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Steve Maney 920 pistons and barrels =£998.00. :shock: :cry:

If you were trying to keep costs down, and were looking at converting some standard barrels, if you cannot find any competant local engineers, another option is to go straight to Pete Lovell and cut out the middleman (Emery). This will in my opinion, be both cheaper and a more pleasant experience. If Pete stills does them, he is a nice chap to deal with and does a lot of Norvils engineering work and has worked on Nortons since the seventies. Also he is a good source of info for getting better performance.

http://petelovelldevelopments.com/

I know when I discussed it with my local experienced enginners, they were happy to do it. I explained that there would be daylight showing between the fins after boring out the original liners and prior to inserting the 920 liners, but they weren't perturbed by it. I seem to recall though that it would be done at my risk.

There are days when I wonder if I should have converted it to 920 based on the cost, but as I originally said, you just have to know :wink:

Let us know how you go on.

Another option for you, but very expensive crusader, is as bwolfie says, the Steve Maney 1007 cc.

I gave the 1007cc variant very serious consideration. You know, in for a penny, in for a pound (or thousands in this case), on the basis of, that will be as far as I will go with the engine ever.

The main reason that I didn't was because Steve (Maney) will not machine "electric start" crankshafts for his engines (even though he tells me he has been asked many times....economics I think), and the 1007 requires a bigger stroke and hence a new S/M crankshaft. I didn't want to lose the electric foot, and to a lesser extent the cost decided it for me.

crusadersports wrote;

How do you find the mk2 Amals in terms of clean running/frequency of balancing/reliable tick over?

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(Sorry, just noticed this whilst looking through the posts).Initially they were a bit of a mare, with spitting back and poor running on very low throttle openings, but I've got them running fine now after adjusting the needle and pilot jets. Frequency of balancing is, set them up and leave them in other words once set up they stay in tune, and tickover is reliable. I do run with a Trispark though and this may help the tick over.

The only irritation/prob is the choke. It starts great then after 10 secs will start to bog down a bit, so I have to realease the choke and then when put it back on etc. This only lasts for about 30 seconds or so. I've contacted Amal to see if they did smaller choke jets but apparently they don't.

Hymph . Ran 32 Mk2s on the 750 , no bother . 36 deg BSA Adv unit gave it 500 rpm tickover .
Id have it a iota higher if you have traffic lights in profusion , but only recall one stall in traffic .
Winter in wet oil it'd spin up or stall at the toll gates if you wernt carefull , as the collector would
frown if the coin was in your mouth , or juggle it if in the fins . Can recall being harranged at a party
by a indignant toll collector to who my face looked familiar .( Briefly , he liked pommy M'cycles )
Ran 23 T so best move was 1.200 rpm held for first 20 yds .
More throttle lit it up , through to 4000 in third , well out .SS cam , MkIII type ports , 1 5/8 intakes .

Mandatory to have the chokes functining , as theres no Ticklers ( spell Enrichment device ) .
Was Supposed to be Cable opperated chokes available .

beng said:

I don't know how much the pistons weigh in the current 920 kits, maybe they have light ones that do not require rebalancing? I think the older kits were recommended to go with stronger than stock connecting rods.

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Yes there is a 920 kit with lightweight pistons and stronger than stock connecting rods that does not require rebalancing the crank and gives you a motor that has more torque as well as less vibration - the best of everything.

see the lightweight 920 piston kit at:

http://www.jsmotorsport.com/