max350
Active Member
It sounds like a dirtbike!
My bike project
- Thread starter max350
- Start date
It sounds like a dirtbike!
huckersteve
New Member
A little job on my engine for the winter, Head of Puch 70cc, 19mm "Kina" mikuni copy, reedvalve from puch-polini-reed
This all looks great! So are you planning to fabricate a reed block for the intake somehow? We'd all love to see your progress I'm sure.
max350
Active Member
So here i had thought that my reedblock would look like, it is just a simpel sketch. I will try to make the reedblock as little as possible to avoid losing too much crankcase compression
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RebelHellbilly
New Member
i might try ur sprocket set up 1 day...looks like it works good
max350
Active Member
Thinking of replacing the needle bearing for the pistonpin with a bronze bushing good or bad? Have some badfeelings with the "Chinese" bearing. Now when it starts to rev up to 10k. I have not found any good replacement needle bearing (10mm pistonpin) most mopeds have 12mm pistonpin
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max350
Active Member
The problem is solved. Found a better needlebearing in the right dimension
Stage6 - Nållager (HQ) Extrabrett So I abandon the idea of a bronze bushing
Stage6 - Nållager (HQ) Extrabrett So I abandon the idea of a bronze bushing
Goat Herder
Gutter Rider
Check with a member http://motorbicycling.com/members/foureasy/
I believe he still sells bearings. He has sourced better goodies for these motors!
max350
Active Member
Hello! All Motorized Bicycle enthusiasts, has unfortunately not been as much work on the bike for me this winter, has been very cold here from December to now-20 -30 Celsius almost all the time and a lot of snow.
Will probably do it a bit easier, ignore reed valve i had think to build. must also obtain a different carburetor, Mikuni copy becomes too heavy do not think the attachment to the cylinder will keep any length of time, will therefore try a Bing 15mm or 15mm Dellorto carburettor
A little work, I have at least done on the engine. Cut all channels, found a lot of sand from the casting that I have deleted! Will have to raise the cylinder ca3mm (3pcs gaskets or aluminum plate) to the new highkompressionspiston not take to the punch head.
Will probably do it a bit easier, ignore reed valve i had think to build. must also obtain a different carburetor, Mikuni copy becomes too heavy do not think the attachment to the cylinder will keep any length of time, will therefore try a Bing 15mm or 15mm Dellorto carburettor
A little work, I have at least done on the engine. Cut all channels, found a lot of sand from the casting that I have deleted! Will have to raise the cylinder ca3mm (3pcs gaskets or aluminum plate) to the new highkompressionspiston not take to the punch head.
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![IMG_0019[1].JPG](/data/attachments/27/27915-837678df6676981074b7d0cbe39ce5b9.jpg?hash=g3Z432Z2mB)
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Goat Herder
Gutter Rider
Did you ever get the bearing you were looking at ? Was wondering how well it fit? http://www.twostroke.se/product.asp?product=12930
max350
Active Member
I got the right needle bearings in the same dimension as the original, it fits just fine, to be hoped that the bearing is for those rpm as I'm aiming for at least 9500rpm
A 10-mm needle with a very high quality.
One of the best on the market that are used in a variety of racing engines!
These extra wide needle is needed for some cylinderkit where it would otherwise be too much play.
Size 10x14x15 mm.
more pictures!
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Goat Herder
Gutter Rider
Oh man that does look better its wider! I like that. How much slap do you have now between the piston journals where the rod pin and new bearing goes? Perfect fit? I think I will get one coming!
The stock bearing flaps around in the breeze which is no wounder why it flies apart lol.
The stock bearing flaps around in the breeze which is no wounder why it flies apart lol.
max350
Active Member
Oh man that does look better its wider! I like that. How much slap do you have now between the piston journals where the rod pin and new bearing goes? Perfect fit? I think I will get one coming!
The stock bearing flaps around in the breeze which is no wounder why it flies apart lol.
I can move the bearing about 1.1 mm to each side the piston journals
max350
Active Member
Simple formula to calculate the speed and rpm!
Motor Drive 4.1:1 = At engine 1000rpm/4.1 = 244rpm at front sprocket, 244rpm / 4.4
= 55.5 rpm x tire circumference 2.05 m = 114.2 m/min/60 = 1.9 m/s x 3,6 at 1000rpm = 6.85 kmh
6.85 x 7000 = 47.8 kmh, 6.85 x 8000 = 54.8 kmh.......... also further
4.4 is gearing front and rear sprocket as the sprocket Circumference tires, such as 26tum = 205cm
To get the rpm, you need a GPS or a speedometer whitch is calibrated
Simply insert your own values for your bike
Hope you can understand how I have thought!
Motor Drive 4.1:1 = At engine 1000rpm/4.1 = 244rpm at front sprocket, 244rpm / 4.4
= 55.5 rpm x tire circumference 2.05 m = 114.2 m/min/60 = 1.9 m/s x 3,6 at 1000rpm = 6.85 kmh
6.85 x 7000 = 47.8 kmh, 6.85 x 8000 = 54.8 kmh.......... also further
4.4 is gearing front and rear sprocket as the sprocket Circumference tires, such as 26tum = 205cm
To get the rpm, you need a GPS or a speedometer whitch is calibrated
Simply insert your own values for your bike
Hope you can understand how I have thought!
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RebelHellbilly
New Member
hey there my swedish motorbike bro...i had to came back and re-read this. wut ya got planned for it next? i still love the sprocket set up. been studying the pics
max350
Active Member
Hello! And thanks for that! What I will do next is to replace bearings in the engine, buy a different carb probably a Bing 15mm. Will also build a new gas tank. My dual sprocket will also get an update! So hang on there will be more!
max350
Active Member
Has now started to prepare my engine. Grinds the crankcase so it suits channels in the cylinder.
I've also drilled the extra holes for better lubrication of bearings and seals. Shall also replace the crankshaft bearings + the 2 second ball bearings
I've also drilled the extra holes for better lubrication of bearings and seals. Shall also replace the crankshaft bearings + the 2 second ball bearings
