Need some help and some answers

[AceLtz]

Ok well ive been 4 strokes but now im planning to buy a used fully done up 250r. Ive found a few online. One with a ESR 350PV and another without the PV. I know to 4 strokes so switching is going need a little getting used to. So my question is, honestly how often would you need to rebuild a kit like this? I always take care of my bikes and i only ride dunes.

I do know that 2 strokes really need to be tuned alot more accuratly than 4 strokes, is there anything else important i should know being new to this? ive taken apart and rebuilt 4 stroke engines so im not engine retarded but i just need some tips.

Im trying to learn all i can about the 250r and the things everyones done to them. Its a whole new world now. So if anyones got any threads that they think i should read let me know. Ill be going through the pages of topics looking for anything important. If i get another question and i cant find it through searching ill post it up here. Thanks alot.

[beerock]

a 350 pv is alot of motor for a first time R rider. i do notice people that ride 4 bangers shift alot sooner and when they get on a R they do it as well. so let it sing a bit.

the 350pv is a good motor, its a little to big if you ask me I know that the cranks and rod bearings dont last nearly as long as say a 330 under hard riding, but if you ride it fairly brisky it should hold up fairly good.

the350 pv's or 350 non pv for that matter do not rev out as much as a 310 or a 330 due to the larger piston etc.

350's are brutes and need to be geared at like 14/35-37 depending on where you want the power to come on, there are even some that gear them 15/36-37 +7 swingarms but thats with real high compression, drag port jobs and run 22" paddles

but those motors get rebuilt every weekend or 10 hours or so (if they make it)

If you want to buy good stuff just look at my sig.. ;)

[AceLtz]

I have no problem handling the engines, i was just wondering about the reliability. I dont want to be rebuilding it all the time. I want a balance of power and reliability. I dont know what port jobs the ones ive been looking at had, or any other of the internal parts. The ad just stated they had ESR 350s installed. So im assuming a 310 kit would be nice to have. I guess if i do end up getting one of the 350s then i could swap it, sell it, or somthing like that. Im getting into a whole new scene so i dont know about the rep's of the companies that build 2 strokes.

The one 350PV i was looking is is totally decked out with an LRD frame, LT front/rear, a arms, trick swinger, etc. I could swap it out for a 310 kit if you guys think its that unreliable. I can do the maintenance its just the buying of parts im not looking forward to.

[AceLtz]

Oh, a few more questions concerning it.

1. When it does need a rebuild what am i going to need to buy? New rings + rebore and resleeve?

2. On average whats the price for doing a regular rebuild?

3. Besides spark plugs, jettin, and blown gaskets, what are commong problems that you guys face regularly?

Thats all for now, I promise :)

Thanks for the info.

[86 Quad R]

first off i'm glad to see another cross over to the R--- ight side of quads lol but, seriously.............

as mentioned the 350 whether it be a pv or not is alot of engine to undertake for someone who is new to 2-strokes. not only do they require lots more attention to tuning but should be monitored alot closer than your smaller bores.

the 350 also needs to be built RIGHT. meaning there is alot of attention to detail upon assembly and certain tolerances that need to be met ect ect.

as for how often it should be built. as a general rule of thumb, i routinely do a compression check and rering at about a 10% loss from the reading i got after the initial breakin. at this time i inspect the cylinder, piston, wrist pin and check the lower unit for abnormal slack. or course on a 350 i'd reccomend that the lower unit be checked every so often depending on the harshness of riding.

i'm of the opinion that ya should start out small and grow into a 350 after you've gotten comfortable to owning a 2-stroke. juss my .02

[beerock]

1. when the compression is 20% lower, then when the motor is fully broken in.

2. 100 or so for piston wrings and wrist pin bearing 60 or so for bore job 1-20 on gaskets

3.No issues just make sure the counterbalancer bearing(on the gear side) is refreshed every year or so, If the counter balancer holder has cracks in it thats a tell tale sign that the gear side bearing is worn out.

other then that, adjust your chain and keep your axle tight.


things that are major pluses on bikes your looking for...

1. double bearing axle carrier(or tapered)

2. 89 clutch update

3. hinson basket(if its a 350 may want to look for an 8 plate conversion)

4. aftermarket frame swinger steering stem and arms

stock frames are great but the price the r's are goin for now best to fnd one with what i mentioned

5. beadlocks are a plus, hipers are a major plus

6. OEM plastics

7. aftermarket front hubs

8.+2 or 4 axle etc..

9. quick change clutch cover

you get the picture


if you want longevity and power, go with a 330 its not to big and not to small.

My 330 has the cast ports still(i havent ported it yet) and my bud had a fully ported 350 p/v from curtis sparks and in the upper rpm range i would start to pull him, everywhere else we were even, but im sure he had alot more low end grunt then me. Once i port the 330 it should scream.

and just so you know, those 350 p/v's command around 3500 bux sold separately(motor only!!!) and top ends are prolly around 1200?


good luck

if that one 350pv is nice go for it on the next top end you can always replace it with a 330(since the cases are already bored to fit the 350 you know a 330 will fit ;)

to be honest with you, the only maintenece required that needs to be checked up on more then a 4 stroke is the engine compression once it falls 20% lowere then what it was(so long as the compression was checked after being broken in) thats when you need to do a top end.

usually i suggest to people who are working on a motor that they really dont know the history of is to buy new main bearings(8 ball 89 bearings or cr 250) main seals and a oem 88 crank. this way when you refresh the top end you will know the motor has 2 top ends to go before refreshing the bottom end again...


hope this all helps

[sandspanker]

:) heres what i got . 350 pv up-grade your trans. with youkon gear set. 2 nd gear weak link. i now have a set of baldwin gears and a new case half. I had almost 3 years on my first piston and rings. very hard riding/flat track racing. ( I do not ***** foot around on my machine) and for a 350 depending on port will turn some serious RPM. (so in short good clutch basket,good transmission gears, If you have any other ?'s pm me .

[AceLtz]

ok that really helps alot. The few ive been looking at dont have the full description so ill have to call. Just by the parts i can see the owners didnt cheap out on anything. I will be buying one fully built, which is what those are. The entire chassis are aftermarket (LRD/ Laegers) along with the shocks(TCS/ Axis). Engines look be cared for and not just some home-made job, not sure about the tranny gears.

As for the compression checks. Whats standard compression for 330-350 kit? Whats the stock 250cc compression? From what ive read 180psi is the max for using pump gas?

I wont have a problem on the rebuilds and maitenance, just wondering what im going to need to do. These will be alot easier to work on compared to a 4stroke which have a thousand parts.

[AceLtz]

...Another quick question. What kind of mileage do these get with a 330-350 size kit? Ill be duning so i was just wondering. If no one knows the mileage, how is it compared to a 450r or yfz. Thanks

[sandspanker]

I get very good mileage on my 350 even running it hard. in idaho at st.anthonys it is 17 mi from one end to the other. went down and back with lots of playing in between and made it back to camp. plus it all depends on riding style. seems the more you lug/put a 2 stroke the more fuel it goes through. p.s that is with a stock tank.:)