300ex is phuct, need advice

[1 Slo 300ex]

Well, I got my first quad this week, a 93 300ex. Dude before me cooked the piston b/c he hadn't rejetted the carb after modding the air box and installing a white bros. pipe. Tonight I finally got the case split open so I could fully inspect it. Before it will run, it definitely needs:
-crank
-connecting rod
-main bearings
-a few other internal bearings
-gasket kit
-lots of valve cleaning/polishing (by me)
-massive cleaning to remove all of the little pieces of leftover piston (by me)

Oh yeah, he gave me a new jug and piston with it, so that's covered.

So, do I spend ~$200 on parts (verified on eBay) and hopefully revive this old motor, or do I take the hybrid route and swap in a dirtbike or cbr600f3 (skeet) motor?

Thanks guys,
jake

[400exrider707]

No brainer, fix that motor... a street bike motor would tear that frame apart in a matter of a few minutes.

[1 Slo 300ex]

agreed it would destroy the stock frame, but i've got some decent welding/fab abilities, and my father has his Ph.D in engineering, so a ballsier frame isn't out of reach.

[wilkin250r]

Originally posted by 1 Slo 300ex
Well, I got my first quad

That says it all right there. Baby steps, my friend.


For your first quad, get it running, almost as stock as possible, and have some fun on it. Upgrade a little after a year or so, maybe even jump to a larger machine. Once you learn your riding style, terrain, and what you REALLY want from a quad, THEN you start thinkin about custom projects.

[born2ride14]

get a 250x 300ex or 350x motor

[1 Slo 300ex]

well i guess i'll start rebuilding it then. any recommendations on stuff to do while the motor is completely stripped?

[SET THE STAGE]

personally, i'd say these would be your best choices

1. ditch it, buy a 350x engine and the conversion from powroll

2. fix it, ride it, mod the hell out of it

3. fix it, sell it, buy a 350x engine, etc.

[1 Slo 300ex]

i got it to the bare cases and most of the bearings seem to be shot. I'm buying a parts washer today and gonna part out the bottom end and hopefully find a new bottom end from somewhere...anyone selling one?

[wilkin250r]

Everybody has their own grand hopes and dreams, but they don't often come to reality.

Honestly, I think you're taking the best approach, here. First, with your decision to go with the stock motor, and second, your decision on HOW to get that stock motor.

Rebuilding an engine is complex. What often happens with novice builders is they try to save money by buying used parts (like cranks), and don't replace all the things they should, either because they don't recognize as worn-out, or they are trying to save money.

The end result is, they spend $500 and many hours rebuilding their engine, and it STILL runs like crap. If they were just a little smarter, they could have bought a complete used engine for about the same price, already put together, and saved all the headache.

[CDCHONDAS]

why buy a used engine? who knows their story. Find a respectable shop and tote that sucker over there, unless your doing it yourself. Have fun, they aren't too hard of motors to work on.

[wilkin250r]

Used engines can be a gamble, obviously. But (in my experience), a used running engine is often a fairly safe bet.

You can usually find a nice engine for around $500-$700. But you can almost NEVER get a rebuild for that price. A basic rebuild alone will run that much, with the parts on top of that.

He already said he needs a new crank, and valvework. He's looking at a $1200 engine rebuild.

[1 Slo 300ex]

either way this build isn't going to be cheap, and I definitely won't be buying an engine without either seeing it run, or having a guarantee that it runs. the only 300ex motors I have seen were priced way too high, but hopefully I can snag a bottom end on the cheap. I might have to move to a different displacement honda motor if I can't find a reasonable 300 for sale.