Engine Modifications done by Cagiva

Technical stuff specific to the Raptor 650
Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

just have to be careful when welding things up and grinding them off, don't know if you noticed Pod, I am a boilermaker/welder by trade, I specialised in Aluminium Fatigue Maintenance, and I know welds on ali then ground off stands out, but I'm not too conservant with stainless though, have fabbed and polished it, but never had to repair it.

I know it isn't a water issue with my bike, but the Mistress is very sick. This week she's started to basically run on one cyliunder at idle, and gives the odd backfire on over-run. I'll pop the tank up over the weekend, and pull the airbox off. Have a funny feeling the carb sync screw is self adjusting because I can screw it by hand, and a daily commute up the motorway at "legal speeds" could of put it out. Might have to look at taking the the spring out or shortening it and adding a lock nut to the screw. The symptoms do point to a primary jet, or idle circuit, have to re-read the SV workshop manual again, the first few pages of the fuel system part explain the way the carbies work. I'll also take a spark plug reading, I'm pretty certain all the problems lie in the read cylinder carby, hence the one cylinder running, and it's synced off the front carby.
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dizzyblonde
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Re: Engine Modifications done by Cagiva

Post by dizzyblonde »

Does it run on both cylinders when you've moved off?

If so

Check the air pipes. My SV was running on one cylinder on idle, popping and banging when riding. Took the airbox off and inspected the air pipes to the carbs, and found a wopping great big hole in one! Put new bit o rubber pipe......like a new bike :ride:
Yellow 2001 SV650s,2002 VRaptor
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pod
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Re: Engine Modifications done by Cagiva

Post by pod »

My carb sync screw is easy to adjust as well, but it hardly moves over thousands of miles.
Water in rear carb seems a possibility
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

The little bung in the front vacuum port hose had fallen out, so now's it back to the cough just off idle, so I need to get it sorted.

Will go through the parts list and dismantle the carbs and see what bits I need to replace, got a shop on the hunt for a kit, but they don't think they can get them down here. I want to check to see if any of the needles are worn, and the condition of the o-rings, one of the jets might just have gunk in it. There is also a possiblity that it's sucking air between the head and carbies, I know the clamps don't tension up as much as I'd like them to, and the intake pipes may have a split in them.

Getting parts sent to Oz is a nightmare, 6 to 8 week wait, and the freight costs can be pretty high.
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

The bits you need are all common to the curvy SV650, dont bother ordering specific Cagiva parts.
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pod
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Re: Engine Modifications done by Cagiva

Post by pod »

The most common fault reported with the Carby SV650s is sticking choke plungers, usually accompanied by high fuel consumption.
Stripping carbs means good fitting screwdrivers or having stripped screws instead, some people add a spot of grinding paste to the driver tip to improve grip.
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

I'll definately be getting Suzuki parts mate, Cagiva in Australia keep no parts in stock, everything has to be shipped in with the standard 6 to 8 week wait. I have had the bowls off on the side of the road when I used to have the blocked tank overflow and the water was seeping into the tank and I was trying to get the water out. I find carbies easy to work on, been pulling them apart for close to 30 years.
Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

I decided just to replace the lower carby hose clamps and see if that was the problem, and I don't think it is, will check for certain on the commute to work tomorrow. Haven't had problems with fuel consumption, getting about 350 kilometres to a tank of fuel, and have done about 650 km in a day, and I reckon that's past the limits of comfort on a raptor.

This is the SV650 carby rebuild kit I came across
http://www.amazon.com/01-02-SUZUKI-SV65 ... B002PZDCHQ

I think I'll just replace the o-rings and see what happens, I've had a look at the float needle (when removing water) and they aren't worn (a worn float needle with not have a perfect cone at the end, it will have a groove in it from wear, and not be seating properly, needle and valve will both be worn out and need replacing).
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

Looks like a good deal, handy spares to keep on the shelf if things check out OK.
A faulty diaphragm is also a possibility, although I reckon that would be bad through the rev range.
Is your motor OK apart from tickover/idle or has it lost pep right through?. I know if my carbs are out of balance the vibes go up.

On the SV motor its common to have a failing front pot if rain and crap get to the front spark plug, theres a drain from the plug zone on the head at the RHS , just a hole in the casing, I blast a bit of WD40 in there from time to time to keep it clear. Ive run Iridium plugs for the past 40K, cant fault them.

Have you checked the sparks, its not unknown for coils to fail? Pull one plug at a time , turn with starter motor while earthing plug and check for consistent fat blue sparks.
Theres that old saying , "99% of carb faults are electrics".
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

The cough has always been there, even with new plugs. Already found out about the drowned front spark plug too. The rubber diaphram is one thing I thought might be the issue. When I balanced the carbs one would rise up and then go down and the other would rise up. Is that normal, or any ideas what might cause it?
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

Dont know about one carb rising etc when balancing. The balancer I use is a coil of clear plastic tubing with a ball bearing which runs in a loop. twiddling the balance screw until the ball is centred at the low point of the loop. I balance at a higher tick over , screw in the adjuster so its at 2,500 and balance there, reset tickover when done

The fact that you are seeing one carb responding differently to the other suggests to me that one of the diaphragms is not right , or maybe the slide is sticking.

For investigation , with the air box off i would connect a large syringe to each of the vac tapping points in turn and simulate inlet vac by drawing the plunger , observing the slides rise and fall, if one slide does not move as much as the other then that would be my suspect.
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Re: Engine Modifications done by Cagiva

Post by shedmonkey »

Iv got a morgan mercury guage and it does tend to dance around when you are ballancing. Dont worry about a bit of up and down as your adjusting because when you reduce one carb the other has to work harder. The adjustments are very fine tiny amounts. Also it will be different when you open the throttle slightly. It can take a bit of fiddling to get right. :nod:
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

G'day Shed.....I've just used the good ol' home built loop of tubing with 2 stroke oil. There's definately an issue there as I had a backfire today on the over run at high revs. I've cleaned the tank out but there was originally a lot of gunk in the float bowls and on last inspection they looked cleaned. Could be just a bit of gunk in a jet, but I don't want pull them apart and find I need parts and have my bike off the road. See if I can get it sort next week.
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dizzyblonde
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Re: Engine Modifications done by Cagiva

Post by dizzyblonde »

Have you inspected the carb hoses for holes yet?
Yellow 2001 SV650s,2002 VRaptor
Your Rapter looks like a sci fi robot dragon! and it breaths fire too! It singed my eye brows and boiled my eyes at the lights! smudge
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

The PAIR system causes backfires on the over run, a valve opens when manifold vac is very high and allows air to pass from the air box to the exhaust system, this burns off unburned fuel in the exhaust and makes a backfire. .
It shouldnt do it if just revving with no load , but on the road it will operate when coasting down from speed with a closed throttle.
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