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 »

Pulled the carbs off today, and gave them a good clean. Was a lot of gunk stuck behind the filter that lives under the float needle seat. Just gave it a good flush with carb cleaner. Set the air mixture screws to 1 1/2 turns out(as they were found, someone has had them out because the caps were already out), put it back together and it still has the cough/back fire through either carb. Just did a bit of searching and found these should be set to 2 1/2 turns out and the symptoms would point to that. I'll pull them back off next weekend and re-set the air mixture screws and see what happens then.
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

AH, maybe someone used to working on Old Brit iron had been at the pilot screws, 1 and a 1/2 turns out is the rule of thumb for old Amal carbs.

Make sure you can blow through the pilot jets, these have the smallest orifii and will block first if any crap got past the fuel filters.
Stay calm.
Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

Turned the air mixture screws out three turns(ended up putting them back to two and a half turns) and while my bike was off the road I replaced the stator and regulator/rectifier.
http://www.carmoelectronics.com.au/inde ... _1121_1129
They are a mosfet reg/rec and slightly bigger than original but fit perfectly turned around so the wires go up through the gap in the mounting bracket right beside the battery.

While I was there I slotted the holes on the pickup, just did it with a 1mm thick cut off wheel on a 5 inch grinder and just made both sides opened ended slots, took about 30 seconds to do. Don't really notice the difference, sounds a lot better though! Think I might have to modify the bracket that holds down the cable that goes to the stator so it is held in by only one bolt. I'll just cut off the top of one side (the tab where the hole is) and bend it back towards the other side where it is bolted and put a small weld on it, thus giving the thickness of the metal extra in advance. The bottom part that comes in contact with the cable fits into a slot and should prevent it from twisting. If anyone doesn't understand what I mean, I'll do a drawing up. I'll also have a look at slightly grinding down part of the side of mounting bolt hole just for that little bit more. I'll also scribe 2, 3 and 4 degrees of advance lines on the rotor and and hook up a timing light and see what I get. I'll also test the 2nd/3rd gear ignition retard connected and disconnected while I'm there. Being able to adjust the amount of advance/retard without having to remove the magneto cover is something I have in the back of my mind.

Still haven't got rid of that cough just off idle, the workshop manuals suggest valves out of adjustment.

One major issue I came across while doing the carb rebuild was that the o-rings on the float valve seat can get damaged when you removed them to clean the filters. I found the cylinder filling up with fuel, just take off your air box and look into your carbs. The bike was hard to start and the crankcase filled with fuel and from what I could see, pushed fuel out the breather just above the sprocket and all over the exhaust header pipes. I suggest if you do remove the float valve seat, test them before fully assembling your carbs. Do this by putting your finger over the hole where the float needle goes, hook up a fuel line to carbs, turn the carbs up the right way and if you get fuel running out over your finger, then the o-ring needs replacing. Also unhook the float needle from the float and hold the needle in with your finger, that will test the needle and seat. Be very judicial on how many times you remove them to clean the filters. Rear carb choke/starter plunger was also sticking because of the starter cable getting stuck in the metal bend.

Taking my bike off the road, and giving it a complete make over as I don't need it to commute anymore. Looking at doing a full restoration and repaint as well as a few customizations, I'll keep you all updated. :cold:

Carburetor carburettor carburetter Suzuki SV650
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

Hi Joe, hows it running know, did you cure the stumble?
It does seem like it got a load of very dirty fuel at some point, I will bear this in mind , Ive never looked at the filters in the carbs yet.
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

Not yet mate, think it's a valve adjustment, and that's what the SV650 manual suggests. I have no idea on the mileage because it'd been crashed and had a 1000 speedo on it. The big thing with the fuel is that it sat in the bike shop for over 12 months, I'd watch it on the net for that long before I bought it. I'm having problems with a sluggish starter motor that I've traced back to a bad earth on the motor, and I just want to check that before I go any further, but it's a mongrel trying to get that bolt out from the side, will lift the tank and see if I can get to it from the top over the weekend if I get a chance. It really sucks cause I can't split lanes at the moment, cause it'll cough and die sometime, and then the starter motor struggles to get it going, I've pissed some car drivers off at times :haha:
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

Just a thought , on the carb bodies there is a TPS ( throttle position Sensor) which has a black PVC cable coming out of it , secured by two wee screws. It gives the ECU the throttle position reading, there is a procedure in the Suzy manual for adjusting this , I did it about 8 years ago and havnt looked at it since.
AFAIR you pull the electric connections in the loom then check for an Ohms value at tickover, moving the housing to adjust. Its not uncommon for these to be out of whack.
Next time Im in the shed I will dig out the numbers.
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

I've got the sv650 manual, but thanks mate for the offer :thumbsup:
Been meaning to check the TPS, it had slipped my mind. I may of unscrewed it once during a "I wonder what this does" moments. Hope you managed to download a copy of the parts list I posted Pod, you were one person I was thinking would appreciate a copy.
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

yep I got that , thanks a lot.
Stay calm.
Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

Tested the TPS according to the Suzuki manual and it has failed. Got the new one today ($130 AUD), but I had a little accident on the weekend with a metal cut off wheel and have a hand out of action, so will be a couple of weeks before I get it fitted and find out if that was the problem. Did a bit of a goggle search on failed Throttle Position Sensors and my bike is showing the symptoms of a failed one. The revs fluctuate a lot at idle which I found strange, and this may be the cause.
pod
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Re: Engine Modifications done by Cagiva

Post by pod »

Hey Joe
sounds like you found the smoking gun, hope thats the cure.
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Re: Engine Modifications done by Cagiva

Post by snapdragon »

Aussiejoe wrote:55 years ago-/- but I had a little accident on the weekend with a metal cut off wheel and have a hand out of action,-/-.
OUCH :shock: heal quick
SnappY
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Aussiejoe
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Re: Engine Modifications done by Cagiva

Post by Aussiejoe »

Tested the new TPS and it appears to not be functioning correctly according to the sv manual, it's basically the same as the old one. I haven't checked it with a second multimeter, but I will before I go any further.

Did a bit more research into how the TPS works and what it does, and I think it's time to pull out the big gun, also know as a timing light. Will put some marks on the stator rotor and have a play with the TPS and see what it's doing advance/retard wise. I read a bit of debate about having the TPS set at "wide open throttle". I'll also disconnect the 2nd/3rd gear retard and see what it does.

Can anyone give me a fairly accurate measurement of the outside diameter of the rotor so I can work out how far apart I should place the marks.
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