RGV150 mods so far. Any more ideas please

[puppydog]

Bad advice Sully60. Went on some Thai sites and ended up buying a 16yo wife!
Still she was only $10 + P&P. I defiantly need more power out of my bike now though, as I have to fit a 75-seat sidecar to it for all of her family to fit in when they come over! At least I can hook people up with cheap DVD’s now.

Thank for the advice though I will get searching for Ideas there.

And Vanilla Ice, I got the info from a UK forum. I can post it if anyone wants it

[Sully60]

Still she was only $10 + P&P. I defiantly need more power out of my bike now though, as I have to fit a 75-seat sidecar to it for all of her family to fit in when they come over!

Thank for the advice though I will get searching for Ideas there.

Well I did say stupid cheap

[SixPackBack]

I dissagree. Most people probably don't know or can't be arsed.
Its easier to put down.
It is the cheapest way of fucking with a bike.
.

Is this the same New Zealand I grew up in? FFS people this sort of thing should be encouraged not dowsed in disdain.

Not wanting to piss on his parade fellas but its obvious puppydog has no money and by inference little mechanical experience......if he can't afford to fix it, he can't afford to fuck it!

[koba]

Not wanting to piss on his parade fellas but its obvious puppydog has no money and by inference little mechanical experience......if he can't afford to fix it, he can't afford to fuck it!

Possibly, but he wasn't asking for financial advice.

[tigertim20]

Puppydog:

Ok, I get it, first bike, and no matter what people tell you, youre gonna want to fuck with it, fair enough, when I got my first bike, I got given a spare engine which I promptly ripped to bits hahaha but I learned fuckin heaps!!!
SO tell ya what, I dont know what mechanical knowledge you have but I will give you some realy helpfull links, take a look at them, it will give you a good idea of how engines work, and using those principles, you can start to learn the theory shit and figure out what parts of your engine you can fuck with. so
for 2 stroke engines: http://science.howstuffworks.com/two-stroke2.htm
for 4 stroke engines: http://auto.howstuffworks.com/engine1.htm
Gearbox: http://auto.howstuffworks.com/sequential-gearbox.htm
and http://auto.howstuffworks.com/transmission.htm
Hopefully thats helpfull for you?

[puppydog]

Thanks for some more helpful advice.
Although I haven’t got a start figure to compare to, I would love to take this along to a rolling road to see what it’s putting out. From factory it was supposed to have 26.5hp which for a 103kg bike is not bad.
It is going SO MUCH better now (post mods) than when I got it, it's pulling a lot stronger and revving a lot freer.
I may have more HP than factory now or I may have just helped to push the HP back toward the factory figure by undoing some of the ravages of age.

Either way once I have got the jet sorted I would like to test it, does anyone know where the nearest rolling road to Napier is?

[koba]

Also know there are certain things alot of people don't tell you when you get a two stroke so read up on general maintainence and care of a two stroke engine.

One important thing is to know and understand the oiling system.
Once you do you will realise it is a bad idea to coast down a hill for ages with the throttle shut. The engine doesn't get enough oil to cope with having the trottle jammed back open when you hit the flat and the big end will did a horrible death, sometimes sending half the rod though the front of the engine.

Also if you are pulling things apart make sure they go back together perfectly, if you get an air leak between the carb and engine most four strokes will run hot and crap, a two stroke will usually die.

Take your time to learn, work slowly and methodically, write EVERYTHING down and HAVE FUN

[puppydog]

Thanks Koba I did not know that. It did not even cross my mind that coasting down long hills could be damaging (full throttle everywhere from now on).

I have received advice from all over the world now, but one thing remains constant, and that is tuning 2-smokers is some kind of black art.
A few of the old timers however have told me of some of the things that worked for them back in the dark ages and I’m very grateful for them passing on their tried and tested wisdom.
I’m not sure everything they have told me to try is 100% safe, but you only live once.

[tigertim20]

yeah fuckit!!! go hard buddy, good on you for taking on an ambitious and different project! someone said earlier that we should be encouraging the kind of antics you are trying here, and after some thought, I wholeheartedly agree. when I was 13 I went to my local wreckers (car) and asked for the smallest turbo he had, when I told him I was going to try and turbo charge my DR250 for a "school project" (yea right!) he laughed at me and gave me a turbo for free!!
I did actually manage to get the thing to work, which was amazing becuase I didnt know the difference betwen a conrod and a stator at that point in time, I just kept fucking with it. and it did work!! for about 2 - 3 hours worth of riding, after I heard the noise it made right before its sudden expiry, I decided a noise like that wasnt worth investigating... kinda wish I had stuck woth it now!
Anyway point is, good on you mate! and keep us posted of any figure you produce and what you do. maybe some pics too eh?

[puppydog]

Turbo a DR250!!!!!!!!!!!!!!!!!!!!!!!!!!! I’m not sure I’m that crazy but well done. Maybe you could put us some diagrams on how you did it for all the DR250 riders out there. Who knows we could streets full of DR’s putting out 100HP.

[motorbyclist]

one of the reasons people don't give hint is either they don't know themselves or are sick and tired of getting into arguments over some fine detail.

the golden rule with performance and vehicleslife in general:

Cheap, Reliable, Fast. Pick any two.

I have just cut the muffler into 3 and removed 5cm from the middle and 1 baffle, I also drilled 3 x 13mm holes in the remaining baffle and re-welded.
I have cut a hole it the side of the air box and covered with mesh to let a little more air in.

now here's where getting a bike with some sporting pedigree helps: there are trick aftermarket parts readily available. motorcross bikes are great for tuning and there's no fun police around to tell you to upgrade or to ticket ya for speeding

DO read up on how two strokes work, particuarly the expansion chamber; there is a LOT of engineering in those pipes (even in fours stroke pipes) and by fiddling with the motor you throw all that out the window. also keep in mind engineers have to make compromises to meet emissions laws, sound restrictions, licence restrictions (in japan), and cost/space issues - so there is always room to improve on stock, but as soon as you go forward in one area you usually go backward in another, and more often than not what you lose is reliability.

.....
Now I have altered the exhaust and air box dynamics the bike is sooooo much better to ride but is running a little lean, especially between 7’500 & 10’000rpm. .....

first: it would have been good to give the thing a complete clean and tune before modifying anything so we know what is the mod and what is general maintenance (your mods may actually make things worse than stock).

second: by gutting the pipe and freeing the intake, you have made it run lean. while it is good to see you've gone to rejet it, you need to be aware that two strokes are much less tolerant than fours; run a two stroke lean and it seizes/melts, run it rich and the entire thing gums up with oily carbon.

.
It is going SO MUCH better now (post mods) than when I got it, it's pulling a lot stronger and revving a lot freer.

third: two strokes run better hot. running lean makes it run hot. fix the mix.


improvements to consider:

clean the air filter. better yet replace with something bigger for higher flow.
find/fit/make a tuned expansion chamber and muffler.
ditch the airbox entirely, along with any other unneccessary weight (but be careful of rain blocking the filter).
the bike is only 100kg, but how heavy are you? eat less pies, take a dump, do whatever you can to strip weight and not only will you accelerate faster but you'll stop quicker (ultimately more important) and corner faster.

pull it to bits and clean every last bit of it.

play with the sprockets: this is the cheapest and easiest way to "tune" your bike. want more torque at the wheel? gear it down (bigger rear) but be aware that you sacrifice the top speed in each gear

different brands of oil; some will run better than others. also try different fuels; I find great variability in fuels between suppliers (both company and servo)

I hear that a good mod is to get some cardboard and block up some of the radiator to help the thing run hot. be aware that this may result in seizure, so be careful

rape it. classic newbie mistake is not to keep a two stroke in the revs where it is burning oil correctly. if you don't rev her enough all that unburnt crap juut goes to block the exhaust. yes it'll need a rebuild but in the two stroke world, pistons and sleeves are consumable items.

flywheels - learn from two-stroke specific examples as sometimes you want a heavier one.

and last but not least:

there is no replacement for displacement. Sure, you COULD sleeve it down to 125cc to race buckets, OR you could sleeve it UP to 200cc for MOAR POWAH

I'd suggest loooking around for a 500cc two stoke single cylinder motor from a KX500 or CR500. all this talk of "get a bigger bike" will suddenly evaporate as you tear around with sixty odd horses of fury