I’ve fitted about a hundred Ivan’s jet kits in the past year and in the process picked up a few tricks to make the job a little easier and quicker. Like the saying goes “experience is what you get just after you needed it”. I hope by sharing my experience with you I can help you to avoid some of the frustrations I went through during the first couple of installs.

If you’re thinking about fitting Ivan’s kit yourself, the first thing you should do is familiarise yourself thoroughly with the carb removal and jet kit installation sections on Pat Glenn’s web site. Study it carefully and then ask yourself “are my technical skills, tools and working environment up to doing this?”. No point in ordering the jet kit then finding that you’ve bitten off more than you can chew.

Only you can say whether your skills as a practical mechanic are good enough. If you’re confident with basic servicing procedures and have the ability to follow instructions carefully, you’ll be OK. But if adjusting the exhaust valve or changing the plugs fills you with dread, walk away now. Removing and refitting the carbs is usually what takes the most time and causes most folks the greatest number of problems. Some of the work on the carbs themselves requires a steady hand and a degree of precision. You’ll need patience and you should budget a full day to complete the job without rushing. First timers typically take around 4 – 5hrs but this isn’t a race against the clock. “Do it right, do it once” is a good motto to have in mind.

As for tools and working environment, you’ll need somewhere dry and with good light to see what you’re doing around the back of the engine. A small torch [flashlight] is a must for spotting where some of the fasteners are hidden away. Specialised tools are few and Pat lists all you need on his site. Make sure you have the 3mm hex driver to reach the No 3 carb inlet stub clamp screw. That one is a ‘must have’item as a regular allen key won’t reach. I also took an old jeweller’s screwdriver and bent the blade to form a 90 deg hook. It’s perfect for steering the throttle cables back into place on the pulley. A piece of wire coathanger bent to a hook would be just as good.

Most of the tools you need are probably in your workshop already but there’s a couple that you may have to pay out for. The first is a pin vice to hold the drill bits used to open up the bypass holes. Forget Halfords or the like - try model shops or proper tool and hardware stores. It should cost around a fiver. Don’t even think about using any other kind of hand drill, let alone a power tool. This is no job for a Black & Decker or Dremel!

The next is a Morgan Carbtune II carb balancer. This will set you back around £55 but it’s vital to balance the carbs properly after installing the kit. You’ll also need a long No 2 crosshead screwdriver to reach the carb adjustment screws. Both these items will pay for themselves in short time, as you’ll be able to do all your own routine servicing in the future.

A proper workbench to do the carb mods on is a ‘nice to have’, but any flat sturdy surface will do. I’ve used kitchen tables, tumbledriers and the like - but never when the lady of the house was around!

So, if you’re sure that this is all within your resources, order the kit and assemble the tools you need and away we go…

Preparation

First, get back on Pat’s site and download any of the pictures you think you may need for reference later on. I took prints of key illustrations out to the garage with me. Better than constantly dashing back to the computer with grimy hands to check on some detail or other. Pat’s site covers all that you need to know about this job. I developed a system of working that was slightly different in sequence to Pat’s description but the fundamentals are the same.

Nothing wastes time more than traipsing backwards and forwards to the tool drawers. Layout all the tools needed on a tray under the bike, where you can reach them from either side of the machine.

Get plenty of clean rags to hand and a bowl to catch the fuel leakage when you take the carbs out.

Have a large container ready to toss all of the bolts etc into as you go along. You won’t get any mixed up as it’s obvious where they all belong on the rebuild.

Removing the Carbs

Remove both side panels. Undo the green connector block behind the left panel - this is the fuel gauge sender cable connected to the sender unit in the tank. And while you’re down that side, use a flat-blade screwdriver to ease the 2 carb bowl overflow hoses off the metal pipes just above the front sprocket cover. Don’t lever against the cover itself as it’s only plastic. If you forget these 2 hoses, you’ll end up later with the carbs stuck half-way out and no free hands to get at the hoses. You have been warned!

Disconnect the battery leads. Screw the bolts back into the captive nuts before removing the battery to prevent the latter from falling somewhere totally inaccessible. Don’t ask me how I know this can happen … oh, and add a magnetic pick-up tool to the list of tools.

Remove the fuel tank as per Pat’s directions. Have piece of rag handy to soak up any fuel from the fuel lines when you disconnect them. If the fuel tank is full, expect fuel to overflow through the breather and overflow pipes. So, best to do this job with a part full tank. Pat uses a prop to hold the tank up. In my workshop, I tied some strong cord to the rafters and fitted a hook to one end which I put through the front tank bracket. Adjusted to the correct length, the cord will hold the tank at the desired angle and give better access to the engine.

Push the fuel hose clips well up the hose to prevent them accidentally being pulled off. This applies to all the hose clips that you’ll be disturbing. Murphy’s Law is sure to guarantee that any clip pulled off a hose will fall into the last place you want it to go. Thankfuly I didn’t discover this the hard way - well, not on this job at least.

This is where my sequence may start to differ from Pat’s. Remove the large AIS hose between the airbox and the AIS pump. Pat’s pictures describe this as the crankcase breather hose, but it isn’t [Ok, it isn't :)]. Note how the large cable tie fits around the AIS hose and the fuel line.

Remove the 2 carb vent hoses. Don’t be distracted by the wire clamps around the top part of the vent hoses. You don’t need to touch the clamps as the hoses simply pull off the plastic connecting T-pieces on the carbs. The hoses are ‘handed’ but difficult to tell apart. I used to put a piece of tape on the left one as an aid to my failing memory.

Remove the main fuel hose at the back of the carbs. This one will definitely leak, so have the rag handy again. Push the hose back onto the top of the airbox and keep the rag around it.

Separate the TPS connector block as per Pat’s directions. It may be a little tight and awkward, so be careful and patient. Again, note the fitting of the cable tie.

Next, I remove the 2 air box side panels. Keep a couple of the screws handy to plug the ends of the carb heater hoses. The carb heater hoses can be eased off using a flat-blade screwdriver. Push the clamps well up the hose and plug the ends with the air box side panel screws. Then tuck the hoses over the top of the engine to keep them clear when you remove the carbs.

If the engine was warm when you started work, chances are a small amount of the coolant will expand out of the carbs and the hoses you’ve just removed. No big deal, just don’t panic when you next put the bike on the sidestand and coolant runs out from under the starter motor!

Slacken the choke cable clamp and remove the choke cable. You don’t need to remove the clamp screw completely. Push the cable over the top of the engine. Re-tighten the clamp screw to ensure it can’t fall out when you least want it to - ie, just as you displace the carbs and before you put a rag into the inlet stubs. Friend Murphy will ensure that it will be the cylinder with the open inlet valves … ‘nuff said?

Undo the 10mm nut on the throttle opening cable, and the larger 10mm nut on the closing cable assembly. You need enough slack to be able to remove the cable assemblies from the mounting plate but don’t try to remove the cables completely just yet. At the throttle grip end, slacken the opening cable adjuster locknut and wind the adjuster fully in to give you max cable freeplay. You’ll be glad you did when it’s time to refit the cables.

Slacken the 3mm hex bolts on the inlet stub clamps. Start with the No 4 cylinder first. As you undo the bolt, feel around the other side of the clamp with your fingers for the open end of the bolt. Count the number of turns you take until the end of the bolt is about 1.5mm off flush with the clamp. You don’t want to remove this bolt completely as there’s a spacer which can fall out as you’re removing the carbs. If you’re lucky, it will drop beneath the starter motor. If you’re unlucky, the cylinder with the open inlet valves is about to accept another piece of unwanted scrap metal …

Slacken off the other 3 inlet stub clamps, counting turns as you go to ensure you don’t overdo it. In fact, to remove the carbs these clamps only need to be loosened to the point where you can just about turn them on the stub. Any looser and they can get dragged off the stubs as the carbs are extracted.

Right, onto the airbox side carb clamps. These are much easier to get at and you’ll note that they are not screwed completely together on the inlet pipes. Just snug enough to prevent leaks, with about 5-6mm gap between the ends of the clamps. Note also the angle of the screws on No 1 & 4 clamps. They are set in this position to clear the airbox covers. Remember this on the rebuild.

The next tip is a good one. Push the airbox clamps as tight back to the airbox as you can get them and then re-tighten the screws. This will prevent the clamps from being caught up by the carbs as you remove and refit the latter. The clamps distort easily and although they can be bent back to shape, it’s an aggravation you can live without.

Loosen but don’t remove the 3 x 10mm bolts that hold the airbox in place. One’s behind the fuel pump (pull the pump off its mounting to get at the bolt) and there’s another in the same position on the other side. The last bolt is on the top of the airbox at the front. Loosen this one last, pull the airbox back as far as it will go and then re-tighten the bolt to keep the airbox out of the way.

You should have about 4-5mm clearance now between the carbs and the airbox stubs. Sometimes, though, the EXUP cables can foul between the airbox and the frame, robbing you of a little clearance. You need all you can get, so move the obstruction and snug the airbox back as far as you can.

Handy Hint No 2 coming up. Liberally squirt nylon and rubber lube spray around and inside the rubber stubs front and rear of the carbs. I get mine at Halfords, but I believe Anne Summers stores also do range of flavoured ones. Our American counterparts use Armorall or similar. This helps the carbs slide out against the drag of the rubber stubs.

Right, you’re now ready to remove the carbs. So, stop and double check that everything should have been loosened or removed has been done. Get a bowl or a large rag on the floor to the left of the bike as the carbs will leak fuel out of the float bowl overflow hoses. Go and have a coffee, straighten your back, have a pee and come back ready and refreshed for the next stage.

Before you remove the carbs, have a piece of clean rag to hand to stuff into the inlet stubs when the carbs are out. Another anti-Murphy precaution, OK?

Stand behind the engine on the left side of the bike. Grasp the carbs at each end and pull them back firmly until they clear the inlet stubs. You may need to rock them up and down a little to free them. Now, ease the carbs out to the left, watching to ensure that none of the clamps gets pulled off the stubs as you go. You will need to be quite forceful and the airbox side rubber stubs will impede you as you slide the carbs out. This is why the rubber lube helps no end. When you get the carbs about two-thirds of the way across, stop and ease the large electrical connector boot over the top of the throttle cables. You may find the choke cable mounting plate will try to foul on the No 1 inlet stub but if you rotate the carb bank clockwise a shade, it will clear without a drama.

Now, Ivan recommends putting the No 4 carb into the No 1 inlet stub to hold the carbs while removing the throttle cables. Personally, I’ve always taken the carbs out completely before removing the cables, but that’s just the method that I prefer. The advantage of Ivan’s method is that it leaves both hands free to work on the cables. My approach requires you to hold the carbs in one hand and to manipulate the cable with the other. First-timers will probably find Ivan’s way easier.

Whichever method you choose, remove the closing cable assembly first (the one closest to the front of the bike), then push the opening cable down to get sufficient clearance between the cable and the pulley to fish the cable nipple out of its housing. It’s tricky to describe and can be just as tricky in practice, but be patient and it will become clear how it should be done. This is where my jewellers’ screwdriver hook tool comes into play. Make a mental note of how the opening cable runs down through the carb bank to the pulley. This is one of the more difficult jobs in refitting the carbs, so a little time studying now will pay dividends later.

Once the carbs are out and the cables disconnected, put the carb bank somewhere safe and stuff the clean rag into the inlet stubs.

Before you dismantle the carbs, you’ll need to drain off the fuel in the float bowls. If you tip the carbs back and forwards, the fuel will come out of the overflow hoses. It will take several cycles before the hoses run dry.

Congratulations - the most difficult part is done! Now go install the jet kit then return here for tips on reinstalling the carbs.

Reinstalling the Carbs

Check the TPS setting as per Pat’s site. I’ve tried Ivan’s dynamic TPS adjustment method but prefer the way my bike runs on the correct factory setting (5k rpm on the tacho). If you want to try Ivan’s method, I suggest you scribe a line across the TPS unit and its mounting plate so that you can return quickly to the factory setting later if you wish.

Check and adjust the exhaust valve cables as per Pat’s site. Be sure to use plenty of copper grease on the cover bolts when you refit them.

Connect up the carb balancer gauge hoses to the inlet stub vacuum pipes.

Replace the fuel tank as per Pat’s instructions. Connect the fuel line and turn on the fuel tap.

There’s no need to connect the overflow pipes yet, or to replace any of the other AIS and float bowl vacuum pipes. The latter just get in the way when attempting to find the carb adjustment screws. On that point, this is a good time to get a torch [flashlight] and locate all 3 carb adjustment screws and to check that you can reach them with your long No 2 crosshead ‘driver.

You’re now at the moment of truth. Will it start? Patience - don’t hit the starter just yet. Check all the fasteners and hoses front to rear one more time. All secure? Good! Ignition on, full choke and wait for the fuel pump to stop clicking. Thumb the starter …

… starts great, eh? Ease the choke off and let the bike settle to an easy idle at 1500rpm. You may need to adjust the idle screw as you disturbed it doing the carb mods.

Let the engine warm and then drop the idle to around 900 rpm for the carb balance.

Follow Pat’s instructions for carb balancing. I suggest the lower idle speed as the vacuum signal is a little better and any imbalance will sound more obvious, not just show on the gauges.

You’ll find that it takes only the tiniest ‘tweak’ with the screwdriver to make a discernible difference on the gauges. You also find that you can sometimes end up chasing the balance between each individual pair of carbs. You’ll get No 1 & 2 correct, then No 3 & 4. But as soon as you adjust the left and right pairs against each other, the individual pairs will drift slightly off again. Just be patient and you’ll get there in the end. Once you have the balance right at 900 rpm, increase the idle speed to 1200rpm and check that the carbs remain in synch. Fine tune again if necessary.

If it’s taking you more than 10 – 15 mins, shut the bike down and let it cool a while, especially if you’re working in a warm climate. Oh, and make sure the garage door is open … that carbon monoxide buzz soons wears thin.

Once the carbs are balanced, remove the gauges and refit the vacuum pipe caps and the AIS vacuum hose. No 3 is a bit tricky to reach, especially when the engine is hot. I hold the cap over the stub with the magnetic tool and press it down with a flat blade ‘driver. I find it easier than fiddling around with bent-nose pliers.

Replace all the hoses and cable ties and lower the fuel tank. Use threadlock on the front tank bolt on pre-03 model bikes. Some late 02 and all 03 onwards bikes have the larger tank bolt which doesn’t vibrate loose like its predecessor.

Reconnect the green fuel sender connector under the left hand side panel. Replace all the side panels …

…. And that’s the job complete. Well done! You have now joined the ranks of the ‘Ivanised’. You should find that the motor now starts easier, pulls stronger from small throttle openings, picks up quicker and generally feels fitter in all respects. Plus you’ve learned a lot about the innards and workings of the carbs and the layout of the engine. You’ve also done about 50% or more of a minor service, so you’ll be in a position to do your own maintenance from here on (unless you’re paranoid about collecting dealer service stamps in your owners’ book).

Enjoy your ‘new’ bike and keep it shiny side up, alright?

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Last Updated: 03-12-2004

Copyright © 2001-03, Patrick Glenn, All Rights Reserved.
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The information presented here reflects solely my personal experience with my motorcycle and is presented for entertainment purposes only. No information presented here is to be relied upon for issues of rider safety nor to replace the services of a qualified service technician. Any attempts to follow or duplicate any of these procedures are done so completely at your own risk. By reading the information on this site, you agree to assume complete responsibility for any and all actual or consequential damages that may arise from any information presented herein.