Just got 2 DB30's milling head question and gearing?

[xxllmm4]

Hey everyone,

Well I'm pretty stoked, I have been looking at these mini bikes for quite a while now but have always had other things to buy. A couple days ago I went into the local Shucks and they where $169... wow great buy. Then my wife says, theirs no way your getting just one of those and the guy behind the counter says if you buy 2 I'll give them to you for $150! Well guess who just got 2 DB30's :thumbsup:

Anyway I want to set them up for some serious hill climbing, as in climbing steep hills form a dead stop. I have done quite a bit of reading on the TAV torque converters and the 6.5 clone conversions. My wife is only 120 and I'm 220 so hers will probably keep the 97cc engine.

So question #1 can the stock 97cc head be milled to increase compression? I was thinking of running E85, been running it in my mower and my truck for the last 2 years with no problems.

#2 what is the ratio of gearing on a torque converter? I was thinking of going with the 10 tooth TAV

Thanks,
Jordon

 

[Fullthrottle]

If your going to do "serious" hill climbing like you say, your better off with the clones in both. At least you can modify these engines more easily and parts are more readily available. There are alot of members who have "hopped" these motors up and know their s**t! These clones can be picked up at Harbor Freight every 2 months or so for $100. Question#2- Use the search button on our site for this and all info, including doing over your DB30's. This question has been asked so many times, especially by new members. You'll get all the info you need on this using SEARCH. SEARCH is your best friend on this site! WELCOME ABOARD!!





Together we stand-Divided we fall. Mini's forever!

 

[xxllmm4]

Yes I understand what the search function is and neither of the answers are there. Nowhere can I find what the gear ratios are with the torque converter and Nowhere can I find info on milling the head of the 97cc engine. But thanks.

Jordon

 

[Strigoi]

i've never seen anyone mention milling a stock 2.8 head on here. no one really bothers with those motors because they're weak. most everyone swaps in a 6.5 because they've got plenty of power and lots of mod potential.

edit: this applies to the 6.5 w/ a 3/4" shaft: i checked on the TAVs and it looks like the 10t one is for #40/41 chain. the 12t is for #35 chain (which is stock on the DB). i didn't look real hard so i'm not sure if they make a 10t for #35. i'd go with that because swapping to a bigger chain is going to be kind of a pain in the ass on the DB.

i've got to get back to work so i can't look for info on the 5/8" one right now.

 

[Jay Wrix]

Ditch the small motors on both,

Even with milling the head it would still be weak, if your lucky youd get 3 horsepower out of it...

youd have to mill it so the valves cant touch the head, and that would be how much max you could do, Hopefully you wouldnt blow gaskets, and you would have to run the proper octane fuel, for 150 bucks, you could have a better motor, and even without a TAV its going to pull alot harder:thumbsup:

 

[TT]

Welcome to the Forum!!

Keep the wife's bike stock until she complains and she will. As all women do! This way she moves up slowly. If she cannot keep up, then do another swap. She needs to learn like everybody else>? Why get her hurt with a 6.5 hp unless she has years of riding seat time. Forget milling the head. Change the rear sprocket and tweak her's for at least six months. She can putt around and then do your hop ups. As for your's buy the cjtmini kit and be thankful you got two new one's for $300.00 Sell your 2.8 hp on eBay and get back $75.00...... Spend that money to get yours completed. I know nothing about the TAV 2 ask around if you want that $100+ part??? Buy 2 helmets, wear boots and gloves!

TT

 

[mini99]

When I bought my DB I rode it for about 10 min. before I tore the motor apart.
I took about .035 off the head, reground the cam and lengthened the lifters, advanced the timing as far as I could by slotting the coil, junked the air cleaner, drilled the main jet out to run it on methanol, and built a header. I also put a 72 tooth sprocket on it with shorter tires.

You could tell a difference, it would run between 40 an 45 mph, but still 0 bottom end.

One good thing, I spun that motor until it ran out of rpms all the time and it still runs fine.