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SirLanceUK

CVRT Heat shield

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I have an issue with the idle speed on my Spartan petrol engine. Talking to people who know I find I have to adjust the idle screw which of course is the wrong side of life.

There are a couple of options

1 lift the deck that should give me access, but of course I have to adjust the screw, put back the deck back, run the engine till hot and see if I got it right, it not lift the deck again and make another adjustment and so on

2 cut a hole on the heat shield  between the driver and the engine large enough to see and get tools in. Issue I would have to make a plug to replace the heat shielding I remove

(not really an issue) but what is the existing heat shield made of, could it be asbestos (not something I really want to be cutting and creating dust).

So can anyone confirm what the heat shield is made of or suggest another way to get at the idle adjustment screw?

Cheers 

 

Edited by SirLanceUK
bad grammer and spelling

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You don’t need the deck on to run the engine.

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I've managed to adjust ours through the engine hatches before now, it's not too difficult. 

Edited by Grasshopper

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8 hours ago, Grasshopper said:

I've managed to adjust ours through the engine hatches before now, it's not too difficult. 

Hi,

I had a look with the aid of some pictures and could not even begin to see the screw indicated on the pictures, 

It appears to be under the air intake and next to the fire wall. Is it worth another go :)

The picture was taken while the decks were off, before I took delivery

image2.jpeg

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If you take the seat out and the bulkhead it’s much easier. 

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That is why I thought of putting in a couple of "hatches" (holes) in the bulkhead to give me access to the carb and the oil filter. Which is why I asked what the existing heat shield was made of :)

Or are you saying that if I take the seat out I can get the bulkhead out without removing the deck

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The integrity of the bulkhead (drivers wall) is essential for your safety. It's a firewall to stop fire, fumes and fuel getting to the driver and occupants and killing them.

Both the throttle idle screw and mixture screws can be reached without removing the decking or drivers wall. It requires a little dexterity and knowledge of where the adjustments are located.

 

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Petrol engined bulkheads have fibreglass based insulation. Honestly, cutting holes is uneccessary, removing the top deck is not required, but it is easier to lift off the two engine grills.

setting carb procedure

1. set both mixture screws 1 1/4 turns open from closed (these are on the front base of the carb facing forward) and are protruding slotted brass screws that will turn with very little resistance

2.locate the idle speed screw-this is hard to find-its on the side of the carb nearest the firewall. If you get someone to work the throttle and look at the back of the carb next to the firewall you will see a hexagonal screw head with a slot in onthe moving linkage' find it now before...

3,warm the engine and  turn the idle speed screw to get the lowest smooth idle

4now, one at a time, adjust one mixture screw in or out to get the highest tickover speed. You may need to wind down the idle speed a few times

5. once you have done both mixture screws, and have a smooth low idle, set tickover to 650 rpm

done!

 

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4 hours ago, Diana and Jackie said:

The integrity of the bulkhead (drivers wall) is essential for your safety. It's a firewall to stop fire, fumes and fuel getting to the driver and occupants and killing them.

Both the throttle idle screw and mixture screws can be reached without removing the decking or drivers wall. It requires a little dexterity and knowledge of where the adjustments are located.

 

I did say hatches, any whole would have a metal door with heat shield material on it to maintain the integrity of the fire wall. I am not highly dexterous and have limited knowledge where the adjustments are located... but I will have another go with a mirror and screwdriver again before I resort to cutting 

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1 hour ago, terryb said:

Petrol engined bulkheads have fibreglass based insulation. Honestly, cutting holes is uneccessary, removing the top deck is not required, but it is easier to lift off the two engine grills.

setting carb procedure

1. set both mixture screws 1 1/4 turns open from closed (these are on the front base of the carb facing forward) and are protruding slotted brass screws that will turn with very little resistance

2.locate the idle speed screw-this is hard to find-its on the side of the carb nearest the firewall. If you get someone to work the throttle and look at the back of the carb next to the firewall you will see a hexagonal screw head with a slot in onthe moving linkage' find it now before...

3,warm the engine and  turn the idle speed screw to get the lowest smooth idle

4now, one at a time, adjust one mixture screw in or out to get the highest tickover speed. You may need to wind down the idle speed a few times

5. once you have done both mixture screws, and have a smooth low idle, set tickover to 650 rpm

done!

 

Thank you for instructions, I will try anew before getting the drill out.

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7 hours ago, Grasshopper said:

Not a very good picture, but this shows the location of the idle screw when mounted to an engine:

image.png.2f61bc4a7da52e6ad1f783cf7373e42e.pngimage.png.dfee0d17a88300bd040b52e5db500d24.png

Thank you it is a great help and clearly shows the screw I need to play with 

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Posted (edited)

If I could buy humble pie I would.

This morning I was out playing, had a road wheel to change. So I thought I did say I would have another go now I have seen some pictures at adjusting the idle speed..

Thankfully I did listen to you all as I lay down on the deck with my hand following the throttle links I found the idle screw. half a turn later, engine warmed up and idle now set to 650 RPM and is holding steady.

Thank you all

Oh and the road wheel was changed as well

 

Edited by SirLanceUK
correcting typo's

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I am coming in late on this one, so apologies for that, but my big concern SirLanceUk (is your real name Lance by any chance?) is that the practice of hacking about a vehicle and chopping and changing bits like firewalls is (as already pointed out not required) but it is also butchery of a perfectly good vehicle and when and if you ever decide to go and sell it you may be amazed as to how much concern it gives folks when they see hack jobs on a vehicle. It gives grave concern to buyers and many will low ball you because of it or just not buy it.

Now,  I will also say, that our veterans fought for your freedom to do what you want and I wouldn't hold you back in any way but if you do have to modify, make it a reversible process and archive the original parts and try to avoid a host of new holes and stuff welded on.

My opinion is my own and I share it without charge and it is mine, so you are not obliged to agree, and that does not offend me.

Happy trails

 

 

 

 

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6 hours ago, robin craig said:

I am coming in late on this one, so apologies for that, but my big concern SirLanceUk (is your real name Lance by any chance?) is that the practice of hacking about a vehicle and chopping and changing bits like firewalls is (as already pointed out not required) but it is also butchery of a perfectly good vehicle and when and if you ever decide to go and sell it you may be amazed as to how much concern it gives folks when they see hack jobs on a vehicle. It gives grave concern to buyers and many will low ball you because of it or just not buy it.

Now,  I will also say, that our veterans fought for your freedom to do what you want and I wouldn't hold you back in any way but if you do have to modify, make it a reversible process and archive the original parts and try to avoid a host of new holes and stuff welded on.

My opinion is my own and I share it without charge and it is mine, so you are not obliged to agree, and that does not offend me.

Happy trails

 

 

 

 

Hi Robin,

yes it is Lance.. Thanks for your post I am always willing to admit I am on a huge learning curve. i do agree that you should not go hacking holes without a very good reason. But should I not want to remove the engine to adjust the carb or replace the engine oil filter, then an appropriate small size hole and an appropriate size plate bolted on with heat shielding. to cover said hole did not seem a strange/ silly thing to do.

However as I mentioned I have performed the carb adjustment without the need of doing either. the question is ( for now) academic.

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Lance,

You don’t need to remove the engine to change the oil filter. The first CVRTs went into service 47 years ago, if an extra hole was deemed essential then a modification would have been issued for it at some point.

Chris

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2 minutes ago, sirhc said:

Lance,

You don’t need to remove the engine to change the oil filter. The first CVRTs went into service 47 years ago, if an extra hole was deemed essential then a modification would have been issued for it at some point.

Chris

Hi Chris.

is the oil filter removal achieved through the belly plate then?

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47 minutes ago, SirLanceUK said:

Hi Chris.

is the oil filter removal achieved through the belly plate then?

You can see it if you look up through the belly plate but you will probably need to take the top deck off, the seat out and the firewall out to undo the nut at the top. If you’re doing a service you might as well do the air filter and pressure wash everything at the same time.

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Should be able to remove oil filter and seal through the oval plate underneath as the nut on top of the oil filter housing has a cage fitted over it to prevent it from turning

If you have some railway sleepers to drive onto these squarely as additional clearance underneath helps

 

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