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Post by aeroxbud on Sept 28, 2019 16:00:59 GMT -5
Brought the road tax for the next year. Yes we have to pay tax to ride a scooter on the road! 😱 Do we? Oh yeah I remember Churchill road police station, wondered why they chased us lot 40 yrs ago. Nothing changes Milly. You may be older. But still a reprobate, running from the police. Lol
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Post by milly on Sept 28, 2019 16:11:51 GMT -5
Maybe a bit of truth there aeroxbud. My daughter phoned me up today after I saw her and grandaughter off on the bus and the little one had turned to mum and said graanddads terrible mummy and thats coming from a 3 yr old
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Post by pete130 on Oct 4, 2019 4:07:16 GMT -5
Well I had these made up to locat head on barrel I dont use a head gasket or barrel gasket haven't had any problems except when re taquring head it can move off center and did on last barrel and I ended up putting hole in piston for leaning out and piston hitting head not good they were expensive but hand milled to suit
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Post by pete130 on Oct 7, 2019 1:23:02 GMT -5
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Post by FrankenMech on Oct 7, 2019 19:15:12 GMT -5
Hmmm, do 2T pistons always look like they are several mm undersize in the bore? It looks like you have a big gap all around or is it some optical illusion?
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Post by dexameth on Oct 7, 2019 19:26:51 GMT -5
Hmmm, do 2T pistons always look like they are several mm undersize in the bore? It looks like you have a big gap all around or is it some optical illusion? Shadowplay
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Post by dexameth on Oct 7, 2019 19:30:14 GMT -5
I bought nice mirrors for Sonja. Measured 10mm, got 10mm, didn't realize the Stella's use a different thread pitch. Dang. Maybe I'll swap them for 8mm and nut the bottom threads to sandwich the mirror plate.
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Post by ryan_ott on Oct 8, 2019 12:17:13 GMT -5
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Post by scooterted on Oct 9, 2019 13:53:48 GMT -5
I had a 47mm bbk with a9 cam on my 139qmb, i was always dissapointed with my top speed of 39mph (im a big dude). So today I bought a 50mm airsal, big valve head and a uni filter.
Im actually not sure if ill have time to install and tune it.
Ill have it for later at least.
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Post by dexameth on Oct 10, 2019 12:55:52 GMT -5
I had a 47mm bbk with a9 cam on my 139qmb, i was always dissapointed with my top speed of 39mph (im a big dude). So today I bought a 50mm airsal, big valve head and a uni filter. Im actually not sure if ill have time to install and tune it. Ill have it for later at least. You know the Airsal 50mm kit was developed to use the stock head? You may get a little bit lower compression with the BVH, as some just use a huge bowl as a combustion chamber. Little less power, little more life though. Keep in mind too, that with the UNI filter and that setup you should be 88-95 with the main jet, depending on altitude and temps...
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Post by scooterted on Oct 10, 2019 14:11:15 GMT -5
I had a 47mm bbk with a9 cam on my 139qmb, i was always dissapointed with my top speed of 39mph (im a big dude). So today I bought a 50mm airsal, big valve head and a uni filter. Im actually not sure if ill have time to install and tune it. Ill have it for later at least. You know the Airsal 50mm kit was developed to use the stock head? You may get a little bit lower compression with the BVH, as some just use a huge bowl as a combustion chamber. Little less power, little more life though. Keep in mind too, that with the UNI filter and that setup you should be 88-95 with the main jet, depending on altitude and temps... I did know that its suitable with the stock head. But a 50mm piston with the stock combustion chamber, AND the extra domed area on the airsal piston should increase compression substantially, and id really like to stick with the ethanol free 90 octane fuel i have access to. Also, the head i bought is supposed to have oversized valves (which i will measure to be sure). I figured the extra valve size might be better than the extra compression. But im open to discussion. Thanks for the jet advice. With the 47mm and stock head and airbox im right on with a 92 jet. I figured i would start with a 98 and see where i end up. Edit: In fact i was hoping that the airsal piston would partially negate any lost compression from the bigger head. Plus its light af for a 50mm piston.
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Post by dexameth on Oct 10, 2019 14:49:18 GMT -5
You know the Airsal 50mm kit was developed to use the stock head? You may get a little bit lower compression with the BVH, as some just use a huge bowl as a combustion chamber. Little less power, little more life though. Keep in mind too, that with the UNI filter and that setup you should be 88-95 with the main jet, depending on altitude and temps... I did know that its suitable with the stock head. But a 50mm piston with the stock combustion chamber, AND the extra domed area on the airsal piston should increase compression substantially, and id really like to stick with the ethanol free 90 octane fuel i have access to. Also, the head i bought is supposed to have oversized valves (which i will measure to be sure). I figured the extra valve size might be better than the extra compression. But im open to discussion. Thanks for the jet advice. With the 47mm and stock head and airbox im right on with a 92 jet. I figured i would start with a 98 and see where i end up. Edit: In fact i was hoping that the airsal piston would partially negate any lost compression from the bigger head. Plus its light af for a 50mm piston. Well, if you look at the design of the crown, the piston is slightly taller, by I think .5mm, but then it cuts down in to a channel all the way around. Almost like a full-circle valve relief. The center is then raised again, but all this adds up to a safe compression value. When I purchased it I thought I was getting some crazy domed, super high compression piston but that isn't the case. As far as the head, I played around with the "SMM Big Valve head" with 23/21mm valves. The ports were smaller than the valves! This isn't good, having the port taper bigger towards the valve will actually slow down the air flow speed. I did end up cracking that head, believe it or not, right between the valves and up to the little chamber where the spark plug sits. Best head on the market, the SSP-G 50mm head has 125cc port sizes (23mm intake tapers to 21.5mm valve) and the exhaust is the same way just slightly smaller. This is the head I know run. Allows the use of a 24mm carb and intake, keeping the entire intake system very close to port matched.
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Post by scooterted on Oct 10, 2019 15:40:20 GMT -5
I did know that its suitable with the stock head. But a 50mm piston with the stock combustion chamber, AND the extra domed area on the airsal piston should increase compression substantially, and id really like to stick with the ethanol free 90 octane fuel i have access to. Also, the head i bought is supposed to have oversized valves (which i will measure to be sure). I figured the extra valve size might be better than the extra compression. But im open to discussion. Thanks for the jet advice. With the 47mm and stock head and airbox im right on with a 92 jet. I figured i would start with a 98 and see where i end up. Edit: In fact i was hoping that the airsal piston would partially negate any lost compression from the bigger head. Plus its light af for a 50mm piston. Well, if you look at the design of the crown, the piston is slightly taller, by I think .5mm, but then it cuts down in to a channel all the way around. Almost like a full-circle valve relief. The center is then raised again, but all this adds up to a safe compression value. When I purchased it I thought I was getting some crazy domed, super high compression piston but that isn't the case. As far as the head, I played around with the "SMM Big Valve head" with 23/21mm valves. The ports were smaller than the valves! This isn't good, having the port taper bigger towards the valve will actually slow down the air flow speed. I did end up cracking that head, believe it or not, right between the valves and up to the little chamber where the spark plug sits. Best head on the market, the SSP-G 50mm head has 125cc port sizes (23mm intake tapers to 21.5mm valve) and the exhaust is the same way just slightly smaller. This is the head I know run. Allows the use of a 24mm carb and intake, keeping the entire intake system very close to port matched. Thanks. Something to chew on for sure. I hadnt considered port size. I might go with the stock head. So do you have any idea what kind of compression one would have with the airsal and stock head? Or any ancedotal evidence of necessary octane?
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Post by dexameth on Oct 10, 2019 16:15:53 GMT -5
So do you have any idea what kind of compression one would have with the airsal and stock head? Or any ancedotal evidence of necessary octane? All of my stock, new scooters have called for 91 or higher. Kymco claims 200psi compression on a stock 139QMB engine. I haven't done a test on that setup with a stock head yet. Port size is VERY important, I almost feel more important than the valves for the most part.
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Post by milly on Oct 16, 2019 16:05:53 GMT -5
Today I ordered 2 centre stand springs and a hub nut for the rear wheel on the new qmb139
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