Offset intake manifold debate

[dchevygod]

I only need to wot occasionally to avoid a car or when racing. In fact I've been using my bike 7-8 hours a day looking for work. Only occasionally do I need to wot to hit a hill with some speed. I cruise at +/- 30 mph

I'm thinking you haven't had any experience with my engine. If you had you would know that wot on this motor
Is normal and it can handle it for extended periods. The G43L is THE most reliable motor ever used on a goped, if there's oil in the gas it will last for thousands of miles. And if there's no oil it will still run for over a hundred miles, I've seen a guy that didn't know it was a 2 stroke and had been filling up at the pump. His motor was still running. And the jug didn't have a scratch?!?

 

[Fabian]

I have no choice but to agree with you that i have not had any experience with the G43L, because i haven't, but i will still maintain that it's reliability would be compromised with endless (continuous) hours of use at WOT at 12,000 rpm.

If SickBikeParts made a (centre mount) shift kit for the G43L, i would most certainly like to try it out.

 

[dchevygod]

I agree only five years of service is to be expected when raced or run hard, instead of the 12 my bottom end has given with only one new cyl/piston and that's because it was ported not because the original was worn out!

I have always wanted to do a center mount with a 460 and I don't think it would be too hard if you start with a 49cc center mount plate. I'm all about power and such. But a belt drive center mount g43 would be awesome as well I think.

My setup really limits gearing options as is and a jackshafted 3spd hub with belt drive to the wheel sounds like a winner to me! I just wish I had the $1500 to build it right. I'd do a Motobecane 21" frame with a gebe sheave, center mount plate, and set it up as a single speed first. Then I'd adapt the 3spd hub in to a jack shaft for a shifter conversion.

 

[Fabian]

If the G43 is such a good engine, SickBikeParts should look into engineering their shift kit to accept the G43, to give an alternative engine option for those people looking for exceptional reliability if they choose to run a 2-stroke engine.

How does the G43 perform with a standard exhaust/muffler system?
I am not interested in having an expansion chamber hanging out the side of the bike. I don't give a damn if it reduces engine power because i want it to be as quiet as possible.

 

[dchevygod]

Thinking more about how SBP has there 4 stroke kit setup, I think that a G43 or a CY460 could be easily adapted to the standard 4 stroke HD shift kit. I know that a freewheel can handle the power since I use one on my LSD setup. The jackshaft just needs to be geared to the rpm range these motors run in and in the correct sprocket size. It would take some time to crunch the #'s to get the ratio right but it should be achievable.

 

[Fabian]

Are larger capacity versions available, in the 60 or 70cc range?

 

[dchevygod]

If the G43 is such a good engine, SickBikeParts should look into engineering their shift kit to accept the G43, to give an alternative engine option for those people looking for exceptional reliability.

How does the G43 perform with a standard exhaust/muffler system?
I am not interested in having an expansion chamber hanging out the side of the bike. I don't give a damn if it reduces engine power because i want it to be as quiet as possible.

The g43 I currently run did gain like 5mph when I added the pipe. But the lower rpm isn't affected much at all. Actually my pipe takes a tiny bit of torque away from the low rpm. Your are lucky This motor g430rc-g43l already has a tunable 12.5mm carb. You can get a 15mm "WYK-58" and a HP filter but it's louder than stock.

As for quiet you won't get any quieter! If you leave it all stock this motor is whisper quiet! The covered intake really helps reduce the noise and the stock exhaust is as good as it gets. My motor is race ported and with a modified stock can on it is really restricted in the high rpms but it's quiet as a mouse fart!

Since your going shifter it shouldn't matter much at all that your high rpm will be about 9500 loaded. I'd definitely still install the juice box for a proven low RPM torque/HP increase. This motor will last the test of time if left all stock, I just don't think that way though! MORE POWER!!!!

 

[dchevygod]

Are larger capacity versions available, in the 60 or 70cc range?

There is a Zenoah g62 but its not affordable "over $1200 in the state we could use it". And the power that the stock G43 makes "reliably" can't be beat.

 

[Fabian]

Only from an aesthetics point of view, i will say that the conventional Chinese 2-stroke centre mount engine looks like a proper engine, whereas the G43 looks like a whipper snipper/weed wacker power head.

Can you get billet cylinder heads for the G43 with significantly greater cooling surface area?
I spend a lot of time off-road negotiating goat tracks at 3 - 5 mph; hauling a lot of weight up steep gradients. The engine would be under a lot of load with next to no airflow moving over the cooling fins?

 

[dchevygod]

Headkits used to be available, you may get lucky and find one used. Because this is an old motor that has been replaced by the gp460, that's way too loud "even stock". The g43 has a cooling fan on the flywheel! I don't get your concerns about slow speed? I get slowed to less than 5 mph all the time on the hills here, I've only experienced power loss once from heating it too much one time and that was with the stock exhaust can heating the jug, it runs way cooler with the pipe installed. A poopoo pipe will do the same thing and be even more quiet and restricted than the stock can. The fan shroud can be trimmed so it looks more appealing. Or removed if you locate a head kit.