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Post by stormn on Feb 2, 2005 17:33:06 GMT 10
Firstly I know there is a thread that has already covered this but the link that explains how it is all done no longer works.
I have downloaded the pdf manual, printed and binded it, the manual shows were the front cylinder vacuum port is, but nothing for the rear cylinder I have had a look and from what I can see the vacuum port for the rear cylinder is used to activate the fuel tap.
Has anyone balanced their carbs, and are my thoughts correct
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Post by yellowvtwin on Feb 2, 2005 17:48:56 GMT 10
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Post by stormn on Feb 3, 2005 10:21:46 GMT 10
the vtr1000f link doesn't appear on my web browser
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Post by yellowvtwin on Feb 3, 2005 16:20:42 GMT 10
One of the common complaints of VTR owners is the unusual ability of the engine to quit on it's own, usually in the most inconvenient places, such as the middle of an intersection! Sometimes the engine stumbles hard and emits a clunk or a backfire through the carb(s). Some call it "character" of the bike. I call it a pain in the ass! This problem is usually attributed to the carburetors being out of synchronization. Follow the guidelines below to aid in sync'ing your carbs. The tools you will need are: Mercury sticks or Twin-max carb sync tool 1/4" drive 7mm socket, 1/4" universal, and 6" long 1/4" drive extension 3/8" drive 4mm allen socket, 3/8" drive universal, and long 3/8" drive extension 8mm combination wrench Small vacuum "tee" and a vacuum cap to fit it Small length of vacuum tubing to fit the carb sync tool fitting Only one vacuum hose gets tapped into. That would be the skinny one going to the rear of the petdoodle. Get a small tee and rubber cap from the auto parts store, cut the line in a convenient spot, and when you're done cap it. See the pic below: As for the front cylinder, there's an allen head screw near the rubber intake boot. Here's a pic of the screw Attach a piece of vacuum tubing to the fitting and use that to screw the fitting into the engine. I use the 8mm wrench to guide it into the hole as follows There's only one screw that needs to be adjusted to sync the carbs. See, one carb is operated by the throttle cables while the other one follows it. You only adjust the one that follows the lead carb. IL4s are a PITA, twins are easy. It is on the left side of the bike, up under the tank towards the back. Use a flashlight to look for it. It's 7mm and is easily reached using a socket, universal, and extension. No ratchet required as it is only spring loaded. Lifting the rear of the tank may aid you a little, but it is definitely *not* required that you remove it. Here's a pic of the screw you need to adjust Hook up your mercury sticks or TwinMax. Start the engine and allow it warm up a little. Do NOT blip the throttle! Operate it smoothly or you will suck mercury into your engine. That can't be a good thing. Adjust the carb so that the two mercury columns dance as closely as possible together. Check it at 4000 rpm. If there is a bigger difference at 4000 than at idle then adjust so there is equal difference at both engine speeds. Honda spec is 20mm (0.8") Hg. You're almost done! Unhook everything and cap the vacuum tee. Put a little grease on the end of the allen screw so that it won't fall off the allen head socket. Tighten it snugly. If you raised the tank, reinstall the tank bolts/nut. Start the bike and go for a ride. Engine run and idle smoother? Probably. This should become regular maintenance on your bike every 6 months or so. OK I have cut and pasted the page taken from Gregs Honda litre bike online thanks Greg
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Post by stormn on Feb 4, 2005 10:14:01 GMT 10
Thanx for that it was most helpful
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Post by bluestorm03 on Feb 4, 2005 14:40:12 GMT 10
Okkkkkkkkkkkkk ya got me sounds like my bike coughing spluttering grrrrrrrrr so where do i get one of these carb synching tool gismos and how many weeks wages and a testicle is it going to cost me haaaaa
go the BLUESSSSSSSSSSSSSSSSSSSSSSS
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Post by stormn on Feb 7, 2005 10:55:03 GMT 10
I got myself a Morgans Carbtune II, bought it off the internet cost from memory about $140 and it's so damn easy to use. I do all my own servicing and the carbs have not been sync'd since I bought the bike, Hooked it all up yesterday and they were perfect, they were about 2-3mmHG different Honda reccommends no more than 20mmHG.
My advice is get brass screw in nipple and route a vacuum hose from the front cylinder to a more accesible place, unless you have hands like a midget it's very fiddly.
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Post by carbtune on Sept 29, 2005 10:59:57 GMT 10
If you're after a Carbtune, check out www.mcp.com.au/carbtune They are supplied from Australia and therefore don't fluctuate with the exchange rate. They come with complete instructions on how to sync your carbs and, as others have stated, are really easy to use. They take a lot of vibration out of the engine and make for much smoother and more efficient running. Most of the time they have them in stock and can ship within a day.
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macca
Senior Member
2001 - Lapis Blue Metallic
Posts: 322
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Post by macca on Jan 7, 2016 21:07:18 GMT 10
Hi all, I know I'm (very) late to the party on this, but I've only just now got around to cleaning out my carbs and have used the opportunity to permanently install a vacuum hose from the front cylinder vacuum takeoff point to make balancing the carbs easier in the future. I've also installed a T-piece in the rear cylinder vacuum hose. Having done this, I'm still not quite sure how to use the carb syncing tool (a cheap one with the two balls in the clear hose). When balancing the carbs, where do I fit the two ends of the carb sync tool hoses? The Haynes manual makes it sound as though hose C in my diagram should be disconnected (or blocked off) and the gauge connected to the t-piece, but that surely can't be right... Picture attached to try and show what I've got setup now: Thanks all! Macca
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macca
Senior Member
2001 - Lapis Blue Metallic
Posts: 322
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Post by macca on Feb 2, 2016 9:16:36 GMT 10
All sorted. It was as easy as it seemed! Connected to points A and the T Junction between B and C.
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vtrstormer
Admin
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Carb Sync
Feb 2, 2016 17:52:12 GMT 10
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Post by vtrstormer on Feb 2, 2016 17:52:12 GMT 10
Was it along way out?
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macca
Senior Member
2001 - Lapis Blue Metallic
Posts: 322
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Post by macca on Feb 2, 2016 18:10:01 GMT 10
Nah basically still spot on. I have the simple 'two balls in a tube' thing, and the little ball rattles around a fair bit. I noticed when i went up to around 4k rpm the ball shifted a bit but not enough to bother adjusting it (yet) I don't think since idle gets pretty lumpy otherwise...
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vtrstormer
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Carb Sync
Feb 2, 2016 18:24:51 GMT 10
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Post by vtrstormer on Feb 2, 2016 18:24:51 GMT 10
Maybe a bit of two stroke oil in the tube will slow the ball bearing down and give a better reading
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Post by kenmoore on Feb 3, 2016 5:53:42 GMT 10
I have the same simple tool.
The balls can rattle around a bit. I use an old clothes peg to clamp the hose a bit to keep the ball from jumping around, acts like a damper.
Simply put the peg on the hose that the ball is jumping around in and squeeze until the ball stops rattling around.
That way you get a better reading.
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macca
Senior Member
2001 - Lapis Blue Metallic
Posts: 322
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Post by macca on Feb 4, 2016 17:07:39 GMT 10
Thanks Kenmoore, will give that a go.
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macca
Senior Member
2001 - Lapis Blue Metallic
Posts: 322
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Post by macca on Feb 6, 2016 15:37:14 GMT 10
Checked the sync again, and again decided it didn't need adjustment. It would seem that the lumpy idle was caused by poor fuel mixture setting on the front carb. I am now 1.5 turns out on the front mixture screw and 2.5 on the rear - seems like too much of a difference but that's what gave me the best idle. Time for a test ride! Also, I found a good spot for the sticker (attached). Big thanks to everyone who gave me help and advice over the last number of months as I had the beast in pieces and didn't know what I was doing. No doubt I'll be asking more questions soon as I install new racetech springs! Attachments:
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vtrstormer
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Carb Sync
Feb 6, 2016 16:11:08 GMT 10
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Post by vtrstormer on Feb 6, 2016 16:11:08 GMT 10
Nice one mate. Good to have it back on the road I bet. How did the caliper go. Sticker looks great to. Let us know how the bike rides now
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macca
Senior Member
2001 - Lapis Blue Metallic
Posts: 322
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Post by macca on Feb 6, 2016 21:11:59 GMT 10
Still haven't fitted the caliper as I wanted to complete the carb and choke jobs before addressing the brake again.
The bike is MUCH more stable at idle, except for the occasional hiccup it pretty much sits at 1200rpm within 50rpm. Previously it was lumpy as hell with swings of +/- 200rpm. I put the improvement down to: 1) New choke Cable (old was broken) 2) Correctly setting the mixture on the front cylinder 3) Reducing the main jet sizes 4) Adjusted my TPS from 780ohm to 560ohm (just by swivelling it)
I also noticed that the bike rarely ever pops (backfires?) anymore on deceleration. It used to do it all the time.
If I blip the throttle really sharply there is still a hangup briefly at about 2000rpm when coming back down to idle, but it's no worse than before and maybe slightly better actually.
I'm going to ride it for a couple hundred kms and then pull the plugs and see how they look.
Next up: sort out my caliper!
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