Big guy needs help

I'm a big guy, around 300lbs. I purchased a 70cc bike and motor but am having lots of problems with it. It seems to die on me all the time, for a wide range of reasons. The thing is, i bought it used, bike included, for only $150, so I don't feel too bad about it, but I'm likely going to buy a new motor kit, and here's where I need some MAJOR HELP.

Again, I'm a big guy, and i will be using this bike to get to work, about 10 miles each way. The problem is, about 1.5 miles of this ride is uphill, some of the hill approaching 20-30 degrees, give or take. What I need to know is, 1) Do I need to go with a 2-stroke or 4-stroke engine. 2) Do I go with the 49cc or 80cc motor. 3) Lastly, and I get competing answers here, for going uphill, do I want a smaller or larger sprocket on the back tire.

PLEAZ HELP, My job may depend on it.

Thanks
Deispring.

Ah, i kinda figured that might be the case, but a friend keeps telling me the opposite is the case. But, what about 2-stroke vs 4 stroke for the torque. will the 4 stroke get me up the hill better.

FYI, TOP SPEED IS NOT AN ISSUE, only getting up the hills.

I've had a few problems with it, including electrical, specifically not getting a spark, the fact that even though it should be hot, on my first outing of 30 min the spark plug wire insulation at the end melted about 1/2 an inch up, and it just doesn't seem to want to continue to work for any given period of time. The main reason I was looking at getting a new kit was the fact that this is a used kit, with a bike, for only $150, so I figure if I get a new kit, I'll be sure to have everything working, and then if I need to make small repairs in the future, i can use this current motor for parts. The way I see it, this motor is a preventative maintenance investment for a new motor. Also, there seems to be a leak in the carb, possibly in the motor as well, the chain is a bit warped, the throttle keeps slipping, and each of the cables involved seem to be of the wrong lenth. Basically, in order to clean up everything and get it back to 100% working order is going to cost me close to the cost of a new kit.

BTW, is there anyone out there who sells smaller chain gears (from the motor side) And what is the largest sprocket you can find out there for the rear rim? Are there any upgrade kits for changing the tooth ratio between the motor and the clutch?

Thanks for the input thus far. And for those who might feel like I'm a bit casual with buying a new motor, let me just say I'm not at all in a good financial position right now, but I've recently be brought up into an assistant management position at work, so I NEED to be 100% sure the bike will get me to work EACH and EVERY Day without fail.

Fondly,
Deispring.

If it ain't broken, it ain't mine.

Well, I had too many problems with the old motor, so I bought a New one, and it's working well enough, though it will work much nicer once I get a few upgrades on it. The Motor is a 80cc Grubee, but all the extras are leftovers from my previous motor. The 48T sprocket seems to get me through most of the hills thus far, but the big hill run comes up tomorrow, and we'll see if it handles it well enough. Then, this friday I should be able to get some of those upgrades, and then we'll be rockin solid.

So today was the big day, and THANK HEAVENS for that Grubee. Not only did it get me to work Okay, but I was able to go straight up the bigest hill in the area with only the TINYest amount of pedaling, and I Tiny like pedaling DOWN a slight slope, it was THAT Easy. Truely, this was the best investment I could have come up with for my transportation to work. I'm still getting those upgrades on Friday, and once that's done, i'll be riding this bike to and from work for the next 3-4 months, until I can get a new car. Thanks for all the support out there, and I will be up here again tomorrow with a few fine-tuning questions, but I just can't think of them at this moment, and as I'm at work, I ought to get back to it.

THanks again for the support,
Deispring

Break, Fix, Ride. Wash, Rinse, Repeat. THat's my motto.