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Post by potatopl on Mar 18, 2014 12:58:16 GMT
Going to order some spark plugs, what NGK values are recommended for mildly tuned Polini 130? B7HS, B8HS, B9HS? What would be the difference between them?
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Post by ttscshaggy on Mar 18, 2014 14:02:54 GMT
The number low to high indicates hot to cold. 7 is a hotter plug that 9. I'd go for a B8. Long distance use a B9
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Post by jeanshorts on Mar 18, 2014 16:00:13 GMT
If you've got the new style head it uses a long reach plug
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Post by potatopl on Mar 18, 2014 16:57:44 GMT
If you've got the new style head it uses a long reach plug I've got the old type one, but it's always good to know. Thanks for the tip I'd go for a B8. Long distance use a B9 So 8 for city use and 9 for touring?
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Post by potatopl on Mar 30, 2014 22:24:41 GMT
Some more work done lately. Intake opened a bit more to obtain straight walls: Port timing measurements. TDC evaluation with piston stopper method (made out of vernier caliper ) Ports at BDC fully opened: The measurements I got at the begining: Exhaust: 88° ATDC -> 88° BTDC = 184° Transfers: 116° ATDC -> 116° BTDC = 128° Blowdown: (184°-128°)/2= 28° After rising the base by 1mm: Exhaust: 86° ATDC -> 86° BTDC = 188° Transfers: 113° ATDC -> 113° BTDC = 134° Blowdown: (188°-134°)/2= 27° Decided to rise the exhaust port by 0,5mm to get 2° exhaust time. Final measurements: Exhaust: 87° ATDC -> 87° BTDC = 186° Transfers: 116° ATDC -> 116° BTDC = 128° Blowdown: (186°-128°)/2= 29° Close to the recommended 125/185 for the Zirri. The exhaust port width is about 61%, so I think it's standard for the Polini and not very bad. Didn't change the width for now, only grinded down all the casting marks and sharp edges. I'm leaving some space for modifications in the future Intake: opens 131° before tdc closes 71° after tdc = 202° Squish 0,85-1,20 mm. The measurements were done without additional gaskets between the 5mm base packer as adding them would increase the squish. I'll use liquid sealant there, hope it will be OK. Head cleaned from carbon deposites. It's pitted in few places but after polishing with fine sandpaper looks OK. Clutch: Second hand XL2 clutch I got from GSF. It was lying dry for quite a long time and corks sticked to the plain plates. Had to use some fine sandpaper to remove the marks. Since the corks looked a bit used I decided to buy a new set. Got the Newfren "Sport" set. Not a big fan of 4 plate clutches, but it was the only reasonable set with harder springs. Made some measurements to compare "standard" with "sport": 3-plates 4-plates Spring heigth: 30,25mm 33,80mmPlates heigth: 10,20mm 10,55mmSeparation path: 1,90mm 3,20mm The total thickness of the 4 plates is almost the same as of 3 plates. However, the reinforced springs heigth is 3,5mm bigger which is reflected in longer separation path. I was wondering, if the standard springs with 4 plates would hold and wanted to test it, but don't have time for opening the clutch again if they won't. That's why I'll stick to the whole "sport" set. Hope it will separate nicely and won't drag too much. I've also cleaned the the casings, backplate, hub and greased the bearing in XL2 clutch cover. Everything looks ready for the assembly which will be done next (or this? Is it already midnight?) week.
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Post by potatopl on Mar 31, 2014 8:37:31 GMT
Few more questions: Gaskets: On my last build I used paper gaskets with hi=temp silicone, since the casings had score marks. The silicone was a ba$terd to clean, when I had to reopen the casings. This time I got composite fibre gaskest material sheets, 0.3mm and I want to cut out the gaskets myself (got the stencils). The sealing surfaces on the casings look good, do you think I could assemble it without silicone? Some say, that it's enough to use just the gasket and a thin smear of grease, to hold it in place during assembly. Did anyone try it? What are your thougth on it? Carb: Got my 25mm PHBL with a bellmouth, no filter and strange jetting. Here it is compared to standard 24 and 25mm at delivery: My 25mm Standard 25mm Standard 24mm main - 120 100 102 idle - 42 50 70 mixer - AQ264 AQ264 AQ264 choke - 60 60 60 needle - D26 D22 D22 slide - 30 40 40 The main jest is very high because no air filter was used, thats OK. The idle is very small though (42 compared to standard 70), maybe it's because the carb was used by previous owner on "racing" scoot (with ported DR133 and PM40 ;]), with constant WOT , sh he didn't bother with idle. Anyway, I've ordered BGM sets: -main jets 6mm 100-122 -idle jets 5mm 50-72 -needles Any suggestions where to start from with the jetting? Air filter: Since the carb has no filter I need to get one. I was looking at some universal, budget air filters and found a few with 38mm connection: A) Foam angled: B) Steel/fiber mesh: C) Foam (not much area, but short so no problems with fitting under the seat): D) Foam + steel mesh (more area): Do you think any of those could work? They doesn't look very different to what Polini or Malossi has in offer. Which one would you recommend?
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Post by briggsy on Mar 31, 2014 18:28:57 GMT
Few more questions: Gaskets: On my last build I used paper gaskets with hi=temp silicone, since the casings had score marks. The silicone was a ba$terd to clean, when I had to reopen the casings. This time I got composite fibre gaskest material sheets, 0.3mm and I want to cut out the gaskets myself (got the stencils). The sealing surfaces on the casings look good, do you think I could assemble it without silicone? Some say, that it's enough to use just the gasket and a thin smear of grease, to hold it in place during assembly. Did anyone try it? What are your thougth on it? Carb: Got my 25mm PHBL with a bellmouth, no filter and strange jetting. Here it is compared to standard 24 and 25mm at delivery: My 25mm Standard 25mm Standard 24mm main - 120 100 102 idle - 42 50 70 mixer - AQ264 AQ264 AQ264 choke - 60 60 60 needle - D26 D22 D22 slide - 30 40 40 The main jest is very high because no air filter was used, thats OK. The idle is very small though (42 compared to standard 70), maybe it's because the carb was used by previous owner on "racing" scoot (with ported DR133 and PM40 ;]), with constant WOT , sh he didn't bother with idle. Anyway, I've ordered BGM sets: -main jets 6mm 100-122 -idle jets 5mm 50-72 -needles Any suggestions where to start from with the jetting? Air filter: Since the carb has no filter I need to get one. I was looking at some universal, budget air filters and found a few with 38mm connection: A) Foam angled: B) Steel/fiber mesh: C) Foam (not much area, but short so no problems with fitting under the seat): D) Foam + steel mesh (more area): Do you think any of those could work? They doesn't look very different to what Polini or Malossi has in offer. Which one would you recommend? Hi potatopl, looking good!! If sealing surface is good on the cases then i would just use some grease to hold gaskets in place, this should be enough. Airfilter - i have ordered the ramair foam sock type filter, this doesnt have a solid end cap so fitting under seat should be easy. They should do one in the size you need.
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Post by potatopl on Mar 31, 2014 18:41:48 GMT
The point is Ram Air is almost 10 times more expensive than the universal ones I've posted ;] Wanted to save some cash here.
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Post by ttscshaggy on Mar 31, 2014 19:17:58 GMT
Foam filters are foam filters. not much difference really. I suppose its down to how close the cells are.
My old rammair was hardly any different to a cheapy one my dad was using. A short one like the one above you posted would be more than ideal
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Post by potatopl on Mar 31, 2014 23:00:47 GMT
Foam filters are foam filters. not much difference really. That's what I wanted to hear The C} option has too small area in my opinion, got a similar one for my SHBC19.19 but didn't have time to put it on and play with jetting. It's because of the chrome cap instead of full foam body. I guess A or D has more air exchange area and they are all foam. What about fiber/steel mesh ones like B? anyone using them with success?
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Post by jonnysnatchsniffer on Apr 1, 2014 17:08:43 GMT
use threebond 1104 on the cases, it seals really good and cleans of easilly on a stripdown, its good for base gaskets and inlet too, no airleaks with it at all
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Post by potatopl on Apr 2, 2014 7:18:35 GMT
Thanks for the tip JSS, unfortunately I don't think Threebond products are aviliable in Poland, never seen them here I've got this german made hi-temp universal sealing compound. Used it before on the manifold and cylinder base. The gaskets were cut out of GAMBIT OIL - gasket material made with use of kevlar fibres and NBR rubber. 0.3mm thickness should hopefully seal properly all the joints, even without additional compounds. I'll give it a try.
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Post by potatopl on Apr 3, 2014 8:01:25 GMT
I've started the assembly. Installing bearings was a piece of cake. I've put the bearings in the freezer overnight, used the heat gun on the casings, and the bearngs poped in without any tapping required. Since I use an ETS crankshaft on standard PK casings I had to use the conversion bearing 6005. To compensate the thickness difference between conversion bearing and the original one (12mm vs 14mm), I've shimmed the socket with 1,8mm thick circlip. I've used NTN C4 clearance bearings for the crankshaft and FAG bearings for primary, tree and rear shaft. Last time, for the DR75, I've used C3 on the crank but since I'm planning to rev the Polini higher I thought it's better to increase the clearance. I got the DRT runner tree with short 3rd and ultrashort 4th. Compared the tapered end with standard tree (non XL2), and it was higher indeed. Tested it "dry", I've put the primary basket on both trees and then triend both standard and XL2 clutch baskets: -standard tree + standard clutch basket - no rubbing -standard tree + XL2 clutch basket - rubbing! -DRT runner tree + standard clutch basket - bic clearance, no rubbing -DRT runner tree + XL2 clutch basket - smaller clearance, but still no rubbing Happy with the result I thought that no tree shimming will be required, so I've installed the tree and put the primary basket in (again with hot/cold method). The primary is RMS helical cut 2,54, I know it's a bitshit but I got it very cheap from Swallow some time ago and since I'm on a budget I had to give it a try (already spend a lot on the Runner). First problem - I forgot the primary basket circlip I'm at work in the Netherlands right now. I took all the parts and tools needed with me to finish the build in my spare time after work. It turns out, it were not ALL parts... I must have left the circlip attached to the original PK 4,+ primary i took out of the engine, which is furrently lying in the drawer in my attic in Poland, 1200km away. Acquiring a new one will take me a few days. Second problem - the clutch rubs on the primary It turns out, that even if you use the Runner, it still can rub with some primary baskets. Compared the XL2 basket with standard one and the first one is wider. I've painted the primary basket with permanent marker and rubbed it with clutch to find the high spots. Then applied some professional machining and grinded them down with dremel. Assembled back, tested and no more rubbing Then I remembered, that I didn't use the casing gasket, which adds some thinkness. Assembled together with the gasket, tested, and unfortunately some more grinding will be required.
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Post by triffid on Apr 14, 2014 19:55:09 GMT
Liking this, lots of info
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Post by scooterfreak on Apr 14, 2014 21:39:05 GMT
i have an ETS head on my polini it has a long plug on and is better than the polini by a country mile
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Post by potatopl on May 5, 2014 15:32:15 GMT
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Post by GeorgeS on May 5, 2014 19:56:04 GMT
Congratulations! Great to see the first starting on video.
Did you have to cut any windows in the piston for boost ports?
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Post by potatopl on May 5, 2014 19:59:25 GMT
The piston is standard Polini item, it already has the boost port window. I didn't cut the 3rd port in the casings though, if that's what you wanted to ask.
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Post by potatopl on May 8, 2014 13:02:16 GMT
Some more movies:
Coldstart, after a few minutes of warmup the engine manages to idle, but the initial opening of the slide has to be set almost to maximum. When adding throttle it smokes more than Bob Marley used to, I'm using good quality oil - Ipone Samourai Racing (Motul brand) 2% mixture. Don't know if it should smoke like that much...
Blowback at idle, looks like I have gone too much with closing the inlet at 71° ATDC. I have fully opened the pad, like most of you do. Didn't take into account that with long pad you can go too far with timing. My sealing pad has 42mm is it short, medium or long one?
I've tripped the engine stand during startup which caused carb overflow. After that I was not able to run it anymore, and the petrol started to leak from the front holes, as I've mentioned before.
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Post by triffid on May 12, 2014 10:01:32 GMT
The excess smoke could be the seal gone, undo your oil drain plug and see if the oil smells of fuel.
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