GP460 Engine On Friction Drive

[5-7HEAVEN]

Went for a spin this morning. It's an 18-mile round trip to Ala Moana Park, a stone's throw from Waikiki. I followed the route to work, then continued on to the park. If the engine is wound up it accelerates up the hills that used to slow me down.

There is a big fat bog between low and midrange.

Need to keep working on the carb.

Two miles from home and idling at the traffic light "The Iron Dragon" engine died. There were a few ounces left in the tank, but it wouldn't restart. Called home but no answer so I pedalled to Wendy's and had lunch. My son brought gas and the engine quickly fired up.

I need a bigger fuel tank!

 

[DetonatorTuning]

how many turns out on the "H" &"L" screws ?

at sea level i don't think you want to go below 1.25 turns out on the "L" screw, here at 700ft ASL i get away with 1-1/8 out on the "L"

you can experiment both sides of 1.5 turns out on the "H" screw but again i wouldn't go below 1.25 turns out.

i have no bog, i apply throttle progressively, like a roll-on rather than snapping it open, don't know how that relates.

a PM to both Zomby and kawasaki999 would be wise, you DON'T want to risk that new topend. believe me, it all over before you even realize with these 460's.

steve

 

[5-7HEAVEN]

Steve, it's probably running very rich. I'll pull the sparkplug right now.

Surprisingly, the plug read brown, almost perfect! Plug gap was less than .025" so I opened it up to .028".

I'll do another run this morning to check. When I get to town the engine temps should be normal. Then I'll check carb adjustments.

Engine idle is pretty high and the clutch is partially engaged at idle. I can feel the bike trying to creep forward.

 

[DetonatorTuning]

i really like the NGK CR8HIX Iridium plugs that DDM recommends and i also run a DirectHits spark applifier thingy. i had noticable results with the addition o fboth.

if your "H" screw is out much more than 1.5 turns you are likely fuel rich there.

you should be able to get acceptable idle and throttle response somewhere from 1.5 - 1.25 turns out on the "L" screw.

i'd try those settings and add just enough throttle stop screw to keep it idling at about 2600-2700rpm and try your drivability again. you can set your idle by giving it just enough throtle stop to feel it trying to push then back it down about 1/16 of a turn.

redo your plug read fairly soon for confidence and security.

steve

 

[5-7HEAVEN]

Leaving home, "The Iron Dragon" failed to start, so I pedalled downhill to McD's. After mulling over the problem I figured the hard starting and tight clutch went hand in hand. So I lifted the rear tire off the ground and yanked the pullstart until it fired up. Major bog in low and midrange, but I rode it like that for a couple miles. It died again, so I readjusted back to stock 1.5 turns. Once started the engine ran much better, with some bog off idle. Ran the bike for five miles, then adjusted 1/8 turn on "L' screw. Much better low-midrange transition, so I rode it home like that.

Used the afternoon to reset and recenter the friction roller. Then I changed the large mounting bolt to 3/8" all-thread. Then I locked the pivoting points up front, then the rear engagement supports.

Remembering that my Whizzer starts with the rear wheel off the ground, that technique might work well. My clutch engages near idling point and that might be why the engine has problems starting. I'll install a two-legged bike stand and see what happens.

Off to the hardware store I go with "The Iron Dragon".

 

[5-7HEAVEN]

Well I installed a two-legged center bike stand, but the rear tire is still on the ground. If I carry a 6" length of 2 by 4, that should put the tire in the air.

Dang, I broke a rear spoke on the stock wheel. Bike shop was supposed to have built a rear wheel w/12g spokes months ago.

This puppy SUCKS GAS!

I must be getting about 43mpg. The two Mitsubishi engines on "The Dragon Lady" use less fuel than this one.

Hmmm, I've read that some 460 owners are getting over 143mpg.

Oh well, at least I can ride "The Dragon Lady" to the bike shop.

 

[5-7HEAVEN]

I Bought A One-gallon Tank!

This is what I bought on Ebay: http://cgi.ebay.com/bicycle-Motoriz...286.m7QQ_trkparmsZalgo=LVI&itu=UCI&otn=3&ps=5

As mentioned before this sucker swallows gas at the rate of approximately 43mpg. The 460 engine emptied my 50-ounce goped tank TWICE today, which is too often for me. I top off my two-liter Happy Time reserve tank every two-three days on my twin-engined "Dragon Lady".

Figured I'd need a larger tank, so I bought this one. It looks similar to the standard Happy Time tank, only larger. My locking gas cap from "The Dragon Lady" SHOULD fit this tank.

What I intend to do is to mount the new tank in the normal top bar location. Then I'll remove the tiny filter and install an automotive FRAM inline filter. The goped tank feeding the engine is in a higher position than this new tank will be located. Sooo I will remove the electric fuel pump from "The Dragon Lady" and install it onto "The Iron Dragon", this 460 engine/friction drive bike. My other bike does not need the pump as I had thought. It siphons quite nicely, although it takes overnight to fill both tanks.

After installing pump and reserve tank, I will drill a hole on the top of the goped tank to accept a 90-degree fitting and a brass nipple. Then fuel will run from this new tank to electric pump to goped tank. I will plug the goped tank's vented fuel cap with a 1/2" screw. Then the engine will vent THROUGH the goped tank, THROUGH the fuel line and pump, THROUGH the reserve tank and out the keyhole in the locking gas cap.

When the reserve tank is in, it should hold enough fuel for a week.

Also need to repair that broken wheel spoke.

 

[DetonatorTuning]

Hmm,

clutch STILL hanging at idle ? set the "L" screw down to about 1-1/8 turn out, then back the throttle stop "BIG" screw out till the clutch lets go. seems you are still idling too high.

unless there is something else going on my GP460 clutch w/ Staton springs doesn't start to grab till 2900rpm.

GP460 mileage. old saying not meaning to be smart a#$, "speed cost money son, how fast can you afford to go" ?

when i was running 19.09:1 stock CR i was getting 160mpg regularly. now, up "about" 21:1 it's 160mpg. i use 1 qt. and travel 40ml. a day. i accellerate to 40mph 6 times a day, the rest of the time i'm on steady cruise. the more your speed has to fluctuate and the more "burst's" of speed you need the more fuel you're going to use.

the more CR you run the more fuel it takes to power around to the next cycle. pull the starter on your stocker and pull the starter on the 13:1 engine, i'm sure you noticed the difference.

you probably don't need the fuel pump. plug the vent in the go-ped tank, tap it for a line from the big tank and tie them together, the walbro will draw the fuel from the big tank first and then the goped tank.

steve

 

[5-7HEAVEN]

Thanks for info, Steve.

The reserve tank can be set up without the pump first to see if it'll feed the header tank.

What I'll do is install a drain valve on my goped tank. That way I can pour in an exact amount of fuel. After draining the excess I can subtract that amount and calculate exact mpg.

Still working on carb adjustment.

Regarding poor gas mileage. I have a stock 460 engine I can swap in and see if I can get 150mpg or more. Maybe I'll try Staton springs. I've heard they engage at 3-4,000rpm.

Actually this 460 friction drive setup is pretty reasonable, notwithstanding mistakes I've made along the way. Anyone can buy the engine for $255, friction drive for $150, $15 for dependable clutch springs.

Dollar for dollar, this is the most powerful rack mount setup available.

 

[DetonatorTuning]

i edited post #188 to correct the rpm my clutch engages with Staton springs

i said 1900rpm it's actually 2900rpm, it was 3000rpm when new and seems to have loosened up some over 1k mls.

for me there was no dramatic diff. in mileage between stock CR and one .005" copper gasket. there WAS a dramatic diff. in starting force and mid-range torque.

there was a real diff. in mileage when i got over blasting up and down the rpm and speed range (where mileage went down to 80mpg) and settled into commuter cruising as smoothly as possible.(now sitting at 160mpg)

i totally agree with your assesment of the 460 friction drive bang for buck value. i hope to hear good things about your next experience with wet weather.

also, i have seen it proposed that the 1" roller is about 23:1 and the 1.25" roller is about 21:1, so there is some possibility that you will be running slightly less rpm at speedthan first expected.

i finally mounted my tach permanently on the bike instead of just using it for setting idle and WOT tuning. i'll be able togive some insight as to what actual rpms real world speeds are attained.

now, back to your original thread............. sorry
steve