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Post by pxguru on Jun 10, 2017 9:20:39 GMT
When buying disk pads take them out and measure them first (Its only one clip & pin). Then buy from a site that gives the dimensions, so you know what you are getting. There are several types out there now and all nearly the same size.
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Post by pxguru on Jun 10, 2017 7:08:13 GMT
The AS atomisers are actually longer and made for 2 strokes. The AV are general ones that can be used for both 2 & 4 strokes. When you open the throttle on either AS or AV atomiser they both go but if you have any interest in economy when cruising along an AS one is the better choice. With a 2.5mm needle (X2, X13 and X7 are all 2.5mm) you will probably end up on an AS264 or AS266. The bigger number is richer and you will have to select the correct one for yours by riding it, after its run in. One size to weak and it will hesitate on pick up, two sizes too weak and it will seize up at cruise! As the PHBH carb atomisers only come in two size jumps you only get one go Make sure it has at least a faint rich splutter at 1/4 throttle and a heavier splutter at WOT while running in and all will be fine. Don't be too keen to down jet before it is run in or it will bite you. In light of my recent experience with mine be sure to check and set the squish clearance when you assemble it. Solder wire and a vernier gauge are the preferred way of checking. Plenty of videos on YouTube And between 1.0mm and 1.2mm is where you are aiming.
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Post by pxguru on Jun 9, 2017 12:00:46 GMT
I'll post all dellorto variables this evening. I can't remember them off the top of my head. Right then, fuelling: Sip fast flow tap Main129 Needle 200 Starter 70 Idle 55 Atomiser av266 Taper x2 notch 2 Slide cutaway 40 How does this sound? I want to be able to run at full throttle without seizing. I've had before on my 125 and it is not fun when it happens at speed! 💩💩💩 Should all be fine to start with. The main thing is the 266 atomiser. It might be a bit big once run in but a good place to start. If you are ever buying more atomisers, I suggest an AS type instead of AV. The AS ones will work just the same but give more economy in the final set up. If you have an X7 needle I would use that for running in. 55 pilot is what I would expect to be close enough. I always like to start with a too big main jet, I would guess 140 would be too big Only put in extra oil (3%) for the first tank. You going to get it bolted on for a weekend of running in? Edit; If you want it to go properly be sure to set the base gasket thickness to give a squish clearance of 1.2mm (or less )
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Post by pxguru on Jun 8, 2017 6:49:19 GMT
Never seen a Sport 210, will be interesting to see how it goes. As far as I know the Sport and MHR look identical but the porting is different. There maybe something stamped on the barrel near the base but to double check the main transfers on an MHR are approx 46mm from the top of the barrel and the Sport main transfer ports are 47mm from the top of the barrel. So a 1mm base packer and no head gasket and you have your own MHR (if it doesn't go fast enough).
If you casings are rough you may need some sealer on the base but nothing on studs or head, as they will both cause damage in the long run.
What needle and atomiser do you plan to start with in the PHBH?
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Post by pxguru on Jun 8, 2017 5:12:54 GMT
Jimscoot, 20/30 degrees F or C?
Pecker, Before you get yourself in trouble again, the AC is the most serious thing you can change in an SI carb. When the AC is changed the MJ will need to be changed and re checked at WOT. Like for example a 130MJ on an 160AC will need to be a 135MJ on a 185AC just to be the similar at WOT. Consider changing the SI carb AC to be like changing needle diameter on a PHBH carb, it's a serious thing to do that affects all other adjustments.
To check the 2mm drilling, the drill bit should go right through from the float bowl to the main jet. You should be able to see it when you look down the jet stack hole.
To make things a bit easier, on a normal set up, the pilot jet is selected by riding with the throttle just open 1-2mm. At this throttle position the pilot jet is doing its main job (and the mixture screw is now bypassed- ie no affect, as pilot is now fully opened ). Once the pilot jet is selected to run well at 1-2mm throttle this is it done. Changing other things like Atomiser and AC will affect it, so may need to be re-visited but go back to riding at 1-2mm throttle and see if it needs touching but usually just a trim of the mixture screw at fast tickover is all that is needed.
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Post by pxguru on Jun 8, 2017 4:54:35 GMT
Which Malossi 210? MHR?
The ports are already chamfered. On a Nicasil bore the chamfer is tiny but it is there.
If you look at the cylinder head, two of the stud holes are slightly bigger than the other two. The 'boccole' collars half press into there to keep the head centered.
What you doing with the jetting and timing to avoid shiny and lovely turning into scored and trash?
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Post by pxguru on Jun 7, 2017 11:53:53 GMT
Shame about the piston melting, they always seem to go really well just before an incident. Must have been pinking like crazy for that to happen. Pinking is not a loud noise but over the years you ear gets tuned to it and the little tinkling noise of doom sounds like a siren.
The two usual reasons for a WOT incident are either ignition timing or main jet. Setting up SI carbs to tuned engines is a challenge. This 2mm drilling that we are doing in the float bowl to MJ is a big help. If a 2mm drilled carb with a 150 MJ will not cause a WOT splutter then a big boys carb is the only option. If the SI will go over rich at WOT, then it is just a case of getting the AC and Atomiser correct. Not easy and highly confusing and I can understand why people give up.
I avoid reeds at all costs. Like a last resort if the engine really needs a 34mm or 38mm carb. I don't like a scooter to sound like a motorbike and secondly reeds don't make quite as much top end power as a rotary valve (but mid range in the wheelie zone is stronger).
Have another go at setting up the SI. If you set the jets in the right sequence it is a little simpler. Timing on the IT mark is usually ok.
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Post by pxguru on Jun 6, 2017 15:50:21 GMT
No filter at the moment just bellows. I have a spare ram air that I will fit under the tank when I get round to it but no great concern for now. No temp gauge on this one. Doing it the old fashioned way by feel and plug colour.
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Post by pxguru on Jun 6, 2017 15:43:06 GMT
Mine is the race head. There are two and they look identical. The race head doesn't have the built in 1.5 mm. I like the 0.9mm clearance and might keep it. The compression is about 13:1 which is my new top limit but the exhaust port is fairly high so trapped compression is still about OK.
You might want to recheck the squish on the beast? Should be not more than 1.0 mm on your smaller bore.
Edit: Had a bit of a think about the squish clearance and getting hot. Best I can come up with so far is that when you close up the squish a greater proportion of the mixture is burnt towards the centre of the head and caught in the primary ignition, which then makes more power, saves fuel and is fairly well documented everywhere as doing so. Conversely if you increase the squish clearance, more fuel is compressed at the edge of the head, which is still burnt but squish mixture is only burnt as a follow on from the primary ignition and possibly even not fully burnt to the edge until too far after TDC, as this squish mixture takes too long to burn it isn't creating more kinetic energy (power), therefore as it does burn and there is an energy conversion in progress it must go somewhere and that would have to be as even more heat (and much more than the increase in compression).
A consensus of all information tells us a 221 squish clearance should be between 1.0mm and 1.5mm. Always knowing that a big squish was costing power and that the 1.0mm limit was just caution (could really be 0.5mm if you are really careful) I always preferred nearer the smaller value myself (the Polossi was at about 0.7 mm for most of it's life). I have never really ran anything with this kind of power at anywhere near the 1.5mm let alone slightly over it, like I said I just plonked the race head on when I got it out the packing and thought I would tweak it later.
Note to self: The more power you have the tighter the squish needs to be to stop it overheating. The list of what makes a scooter overheat just got one item longer.
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Post by pxguru on Jun 6, 2017 15:32:56 GMT
It is unlucky to have such a low mileage with all those issues but at least it is sorted.
There is no issue with some tweaking of it is done right.
Plugs: the number of the plug has no effect on the temperature of the engine. The number is selected after all other work is done to get the plug in its operating range. If the plug gets too hot it will detonate and if too cold it might misfire.
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Post by pxguru on Jun 5, 2017 18:04:54 GMT
Well.....I am surprised I modified the head cowl and closed up the old plug hole now it's centre squish, with pop riveted ally sheet. And re ducted the air flow to be 10mm further forward with more ally sheet (no picture as its not pretty) due to the way the split MRP Race head works. Re-shaped the old Malossi exhaust port to a 21st century design and widened it a bit more too. Test ride was c**p. Revs a bit more freely but overall exactly the same, 152 main jet and temperature sky rockets still when thrashed. Got it up to 355 degrees F which is at least 50 more than safe but luckily no catastophe. Was really running hot and not a gauge issue, as it felt terrible cruising until it cooled down to about 330F. After some pondering I decided it wasn't the cooling. 'the Germans' MRP know what they are doing with heads so isn't that. Jetting is slightly too rich, so not that either. Still at a loss to what is causing the over heating and as it was overheating even at 5000 rpm cruising, changing the timing would have solved it but the further loss of power would be an issue with the P200 gearbox. I decided to fiddle with the porting to get the squish tighter while I was thinking about it. I just plonked the head on knowing the squish was 1.5mm but as the compression is still at least 11+:1 there would be no real issue....usually correct but in this case.....wrong! Compromised the porting a little but closed the squish to 1.2mm. Goes great and gets to 290F max at full thrash. I like this. Straight home and closed the squish some more to 0.9mm (don't do this at home kids) and is just wonderful. Some average thrashing got to 67mph (GPS) in third gear and 75mph (GPS) in 4th and still humping along(backed off as too gusty/windy to keep it on the road today)temperature not over 270F. Next time out I now need to down jet to get the teperature back up! Now who'd have thought that? When the squish clearance is 0.3 mm too big it overheats. I would have had money on the opposite. More pondering required. PS. Put new clutch steels in it while I was at it, as the last ones were looking chewed in the centre when I changed the plates last month.
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Post by pxguru on Jun 5, 2017 17:30:51 GMT
Ran out of time working on it but we might just be down to the final tweek now. Has a wet cough at 3000rpm so will need more air and is still slightly weak at WOT and once the BE2 goes the bigger 142MJ (maybe 145MJ)in will help the lower revs not be too weak with extra air of the BE2. Overall really impressed with this vortex, really does flow more air. Like having a bigger carb on. Has richened it up right accross the range.
For the record when I get back to it. Jetting is now; AC185, BE3+2, 48/160, MJ140, slide 04, 2.0mm drilled
Next time out will be; AC185, BE2, 48/160, MJ142, slide 04, 2.0mm drilled
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Post by pxguru on Jun 5, 2017 9:37:39 GMT
I agree it is certainly running weak. Just need to work out why.
What jets are in it? And does it have a working autolube?
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Post by pxguru on Jun 5, 2017 9:34:46 GMT
From the sound of all your threads it is not running so well. I would put the jetting all back as standard but with a 108 main jet and see how it goes from there.
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Post by pxguru on Jun 3, 2017 7:09:55 GMT
Gearbox oil is normally more white smoke than black.
The mixture screw is probably just too far out.
In most cases detonation is caused by jetting
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Post by pxguru on May 31, 2017 10:21:11 GMT
The carb could just be sucking in the carb cleaner. How far out is the mixture screw? Wind it out 4 or 5 turns and see how it runs, should be terrible and keep stalling.
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Post by pxguru on May 31, 2017 9:55:00 GMT
Expensive lesson Those car u clamps can only be used on a standard 200 barrel. Everything else should use a banded clamp. The old Malossi is the worst offender, as the stub is too small. SIP make some thin packers to make it tighter, which work great.
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Post by pxguru on May 31, 2017 8:55:31 GMT
Onepiecceatatime don't like the look of your plug. Seems too weak. Grey is the colour that comes after white.
Can you remind me about all the jets on your carb? Atomiser, AC, MJ & Pilot.
Also where your timing is set?
While your at it check your speedo. It should thrash to 30mph in 2nd gear and near to 50mph in 3rd gear, if the speedo is ok. Once sorted it should manage just more than 60mph on a good day.
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Post by pxguru on May 22, 2017 16:00:45 GMT
Back with my other girl now and buying her presents. This time it is a Pinasco 26 vortex Upjetted to 138 and could possibly go more. Seems to be running much better overall. Scooter is a tourer and really well behaved but can rev out when required. I might go down to a 45/160 pilot next time out. Has a faint splutter as the revs build up and the main stack takes over. It is either the pilot or needs an even bigger AC. I know if it was a needle carb I would put in a smaller diameter main atomiser and that would sort it but in the SI carb it could be either. Whichever I choose first it will be the other Jetting now AC190, BE2, 48/160, MJ138, slide 04, 2.0mm drilled
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Post by pxguru on May 20, 2017 8:20:23 GMT
So that means between 106 and 111.
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Post by pxguru on May 18, 2017 9:21:06 GMT
I doubt it is anything to do with the fuel pipe. Are the jets screwed in tight? Might be an air leak somewhere. Post a photo of the spark plug and we will tell you what colour it is
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Post by pxguru on May 18, 2017 9:12:54 GMT
I would think a 114 main jet is too big for even a standard 150. Carefully try a jet about 108 and see how that is. It will probably still be too big but see how it feels and go from there.
Never forget that 2 main jet sizes under where is should be will cause overheat and maybe even seize up. Like 135 is perfect, 132 has more power but gets hot and 130 heat seizes. When its right you are never more than 2 jets from risking damage.
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Post by pxguru on May 17, 2017 15:36:18 GMT
Could be doing up the bolt too tight. Are you putting the the speedo cable right in before doing the bolt up? and then just nipping it not so tight?
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Post by pxguru on May 17, 2017 15:06:38 GMT
The one man bleed kit makes it really easy. The hardest part is keeping the master cylinder full.
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Post by pxguru on May 17, 2017 15:01:46 GMT
Are you talking about when at wide open?
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Post by pxguru on May 17, 2017 4:27:11 GMT
Really impressive job. Would never have thought they would end up looking better than new. Only thing I am allowed to paint is the garden fence ;-)
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Post by pxguru on May 17, 2017 4:20:01 GMT
By 'machine gunning' I assume you mean spluttering. Down one main jet size at a time until it revs right out cleanly. As it starts to feel better, do some long runs wide open and check the plug colour to see if you need to go down another jet size.
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Post by pxguru on May 14, 2017 11:03:37 GMT
Barrel doesn't look so bad. Only the scores above the exhaust port matter. If there is anything deep there then you might as well spend your money on a bigger barrel.
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Post by pxguru on May 14, 2017 11:02:13 GMT
It now sounds like not in neutral properly. Gear selector may be loose inside and the cruciform is catching on a cog. Nothing much to worry about if it is this. If you catch it early enough a gear selector overhaul kit will fix it, otherwise its a complete new selector box. www.sip-scootershop.com/en/products/gearshift+arm+selector+box+_12135800If you are really lucky, then the cruciform shaft has come unscrewed and just needs tightening. Take the selector box off and have a look.
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Post by pxguru on May 12, 2017 4:11:06 GMT
I am remembering she is at 19 degrees? You could retard 2 degrees until jetting in is complete, then try advancing again later. See how the temperature is affected? It will lose some mid power but it has so much you might not notice
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