Building a Ht Motorized Bicycle or Three.
- Thread starter Theon
- Start date
She is pulling OK now from 2000 RPM, Bit fiddly getting the idle right as it is very sensitive and best adjusted whilst crawling along at 2000 RPM, she 4 strokes a bit at those revs until you load her up, then runs sweet to 8500 where she feels like she may be a little lean?
Not getting much response from Hi speed mix screw and figure she is drawing the limit from the carb as I can't seem to get her to 4 stroke in the higher revs with screw wound right out.
Puch head seems to be keeping the temp down to 130 Deg C.
Plug looks a little pale.
Not getting much response from Hi speed mix screw and figure she is drawing the limit from the carb as I can't seem to get her to 4 stroke in the higher revs with screw wound right out.
Puch head seems to be keeping the temp down to 130 Deg C.
Plug looks a little pale.
Found another 21mm walbro, this time from a Still.
Cost me a beer!
may try and drill out the barrel carb and see if I can get a bit more fuel through her though as its working well otherwise.
Cost me a beer!
may try and drill out the barrel carb and see if I can get a bit more fuel through her though as its working well otherwise.
Ok, so after a little discussion I had on a different forum last night, I decided to measure the stroke of the crank I had planed on using for my case induced motor.
Seems it is actually closer to 39mm stroke!
Got to love that Chinese accuracy.
So any way I have gone and ordered a rather expensive computer balanced motor from Screaming Roo. Curiosity just got the better of me, It's literally twice the price of most Ebay kits, however comes with all the best bits and pieces that can be sourced for these motors and a crank that is said to be silky smooth to way over 10 000 RPM.
I'm thinking to leave this motor 'as is' for now. And for the mean time I will just build my case induced motor with what I have and see how it goes.
But am likely to pull the crank from the Softtail for my case induced motor as it's shown me 9500 RPM in the past before the vibs really kick in. And is a 5 piece style crank offering better crankcase compression without the need for case stuffing.
At some point I will try and copy the balance factor from this new motor that I have ordered and hopefully get my case induced motor also doing 10 000.
Seems it is actually closer to 39mm stroke!
Got to love that Chinese accuracy.
So any way I have gone and ordered a rather expensive computer balanced motor from Screaming Roo. Curiosity just got the better of me, It's literally twice the price of most Ebay kits, however comes with all the best bits and pieces that can be sourced for these motors and a crank that is said to be silky smooth to way over 10 000 RPM.
I'm thinking to leave this motor 'as is' for now. And for the mean time I will just build my case induced motor with what I have and see how it goes.
But am likely to pull the crank from the Softtail for my case induced motor as it's shown me 9500 RPM in the past before the vibs really kick in. And is a 5 piece style crank offering better crankcase compression without the need for case stuffing.
At some point I will try and copy the balance factor from this new motor that I have ordered and hopefully get my case induced motor also doing 10 000.
yea man. sounds pretty good. i love my headstuds. got them installed. i think im really happy. the rear end of the bike is lighter. i catch air better. theres a point a bike reaches where the weight is greater than the pop> and u catch no air.... im just at the edge of that now. DENSITYdensityDENSITY. 
I'm having the same problem you were talking about with the bike surging in midrange cruise.
Not really what I built this bike for though.
However it loves WOT, Havn't tried getting air on her yet, I think I'm getting a bit old for air on a hard tail.
This new motor I've ordered comes with some rave reviews, apparently should get me 80Km/hr+ straight out of the box.
Not really what I built this bike for though.
However it loves WOT, Havn't tried getting air on her yet, I think I'm getting a bit old for air on a hard tail.
This new motor I've ordered comes with some rave reviews, apparently should get me 80Km/hr+ straight out of the box.
post rejected lol
ok so motor w be a great addition. sounds like a 6.4cc dome i w look at curiously. bearings too cool. i wonder what wrist the bearing assembly is like.
---- ur carb is adjustable and if u adjust outside of a happy midrange ur screwed. so play w pipe theon. pipes pushing up the top rpms requires less fuel so it takes away from the midrange aswell.
lower top rpm by way of expansion chamber. then add fuel on high jet to achieve great happyness
does that help?????
ok so motor w be a great addition. sounds like a 6.4cc dome i w look at curiously. bearings too cool. i wonder what wrist the bearing assembly is like.
---- ur carb is adjustable and if u adjust outside of a happy midrange ur screwed. so play w pipe theon. pipes pushing up the top rpms requires less fuel so it takes away from the midrange aswell.
lower top rpm by way of expansion chamber. then add fuel on high jet to achieve great happyness
does that help?????
if ur pushing up the last 2000rpm i think ur screwed till normal top rpm is found.
---l anyway its not that my bike wont catch air but it would drop off my very experienced feet.... i couldnt help it. it would just drop away. just forget about it said. im to heavy it screamed. density density. its better now.
---l anyway its not that my bike wont catch air but it would drop off my very experienced feet.... i couldnt help it. it would just drop away. just forget about it said. im to heavy it screamed. density density. its better now.
Goat motor felt better without the mufflers, but LOUD.
Ran out of Top end adjustment on the carb, Have ordered another the same to play with.
Has crappy plastic metering nozzle, probably can't get separately, but whole carb from China $15 delivered lol.
Not much room to play with the pipe, it's a bit of a squeeze and has been designed to fit more than work, still it does it's job.
Been wet and I've been busy so not been getting much riding in.
Just eyeing a late model 2nd hand Mongoose for my new motor, but car rego is coming up.
still if I can get it for good price,
Ran out of Top end adjustment on the carb, Have ordered another the same to play with.
Has crappy plastic metering nozzle, probably can't get separately, but whole carb from China $15 delivered lol.
Not much room to play with the pipe, it's a bit of a squeeze and has been designed to fit more than work, still it does it's job.
Been wet and I've been busy so not been getting much riding in.
Just eyeing a late model 2nd hand Mongoose for my new motor, but car rego is coming up.
still if I can get it for good price,
Carb is 15mm Barrel carb, but usually used on piston port, reed with max duration needs richer.
Going to see if I can get it to deliver a little more fuel.
Going to see if I can get it to deliver a little more fuel.
no its 13.5mm/ the 15 is nothing more than its mostly a staiight bore w nominations of 13.5 and 15mm. carb being 15-13.5=1.5 divided by two= 0.75 restriction for venturi. pretty straight bore....but only 13.5mm unless u break the speed of sound wich would make a thunderclap and impress everyone
i cant help u in these circumstance u will be stuck at 13.5 carbs forever. so what if u manage really. how much bs are u going to tune around? its not the carbs fault. i cant sugar coat this situation. the piston is huge for a 0.55 inch carb that flows 0.3 square inches.
i cant help u in these circumstance u will be stuck at 13.5 carbs forever. so what if u manage really. how much bs are u going to tune around? its not the carbs fault. i cant sugar coat this situation. the piston is huge for a 0.55 inch carb that flows 0.3 square inches.
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The barrel carb does not have a venture choke like your walbro.
When it's fully open it is 15mm dia straight through, with the needle being the only restriction.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=370979742794#ht_2600wt_1004
When it's fully open it is 15mm dia straight through, with the needle being the only restriction.
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=370979742794#ht_2600wt_1004
