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Engines and Modifications Get the most out of your motor or just get it running! Discuss engines and modifications in depth.

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Old 05-06-2009, 12:05 PM   #1 (permalink)
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Thumbs up Baja 2.8hp 97cc 4-stroke engine help

Does anyone have any tips for my db30's power and acceleration?
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Old 05-06-2009, 12:23 PM   #2 (permalink)
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swap in a 6.5 clone. the stock motors don't put out enough power for an adult.
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Old 05-06-2009, 03:36 PM   #3 (permalink)
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Hello again

Thanx strigoi u probably remember me better as happy2387, but this is my new account. If u remember I am a kid. only weigh 115lbs. How much would a 5-6.5 cost at a junk yard?
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Old 05-07-2009, 05:07 AM   #4 (permalink)
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If I may say so,why look at a junk yard?Brand new 5.5 or 6.5hp motors are quite inexpensive.Around $130,sometimes even less.

Even a kid with a paper route can save up enough pennies for that.
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Old 05-07-2009, 12:49 PM   #5 (permalink)
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If you know someone who can weld put a jack shaft kit on it, it makes a huge difference. Your gearing will be lower for quicker take off speed but your top speed will be less. If you also removed the Governor you could get the top speed back and have quicker acceleration. If you do put a new engine on it you have the cost of the engine, a new clutch and a mounting kit if you cant do the work yourself so it can add up pretty quick.

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Old 05-07-2009, 02:47 PM   #6 (permalink)
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This is what I suggest. Cry for a job around the neighborhood. Save money, do chores. Get some money together by Christmas time and save yourself money enough to get a CJTMINI kit. In seven months that engine will be a boat anchor anyway, and if your a kid, then you need to learn disipline. If not cry to Daddy or Mommy and get a new engine. If you do not have the tools or experince to do the changeover, you in for an uphill run without the CJTMINI kit. You cannot just hop the thing up overnight, without years of dealing with modifications. Then save and get a car, so you do not have to date a ugly chick...lol

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Old 05-11-2009, 11:58 AM   #7 (permalink)
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All you can really do is to make sure it is running 100% to its potential. There are no mods for this engine, though I have seen someone make an intake for it. You could try making an intake & exhaust, but thats about all I could think of to mod this motor. I dont think they can flow enough air to benifit from any carb upgrades, I think it runs kinda rich from the start. Heres my list of things ive done to maximize the stock engine potential.

1. Carb tuning is the most important thing. I leaned mine all the way out and it was running like a beast but it was also pinging a little. Run it on the lean side, but listen for popping. If it does, add fuel 1/4 turn at a time.

2. Use the right weight motor oil.

3. Make sure the throttle is opening all the way.

4. Make sure your brakes are not dragging too much. They have to "drag" a little for good braking responce though, but not enough to stop the wheel when spinning by hand.
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Old 06-04-2011, 12:15 PM   #8 (permalink)
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Would a honda GX 120 engine work in DB30? It seems to be similar in size and HP.
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Old 06-04-2011, 04:15 PM   #9 (permalink)
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it won't just bolt in. you'll either need to drill/slot new holes or get one of the adapter plates. you also need to get a 3/4" clutch.
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Old 06-11-2011, 10:54 PM   #10 (permalink)
 
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Quote:
Originally Posted by Bajamini View Post
Does anyone have any tips for my db30's power and acceleration?
Well my friend I have 5 simple steps to make your 97cc (2.8hp) engine move that little DB30.

1. Weld up a header for it (I don't know if you can buy them or not).


2. Build a ram air intake out of PVC that comes out by your leg by the recoil, I did it and it made a reasonable difference.


3. Rejet the carb, get a set of numbered drill bits remove the idle jet and drill it out with the #77 bit. I did this an it worked good.

4. On the stock carb there is a black plastic tab, break it off carefully and you will now have access to the mixture needle, adjust it accordingly.
5. Set the gov arm springs to the highest up of the 3 holes, it will rev higher that way. (In the pic I show you do not drill the 4th or 5th hole, the pic is just for clearification on what spring to adjust.


This will result in a moderate speed/acceleration increase, for better acceleration and torque check out the PMR jackshaft kit. My DB30 with the 97cc (2.8hp) engine went 32 to 34mph (on GPS) but I bypassed the governor, and you should not do that I ended up blowing my engine because of it, but it could've been worse, the connecting rod could've came through the seat. I know it is tempting to do, and results in more power, but don't unless you have the billet con. rod and flywheel which are not availible for this engine.
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