Suzuki rg150. Help?

[EUPHORIA]

okay i just borght an 1998 suzuki rg150. it had been going fine for lil while but latly it has had no gutz it revs out at bout 8000 every gear and not 12500.
i thought it could be the spark plug but i just put a new one in (ngk b8es) i think thats the right one for it.

this is my first bike so could someone help me out and any other tips and things i shud do for making my rg150 better are welcome also.

[oyster]

Start with battery, make sure it's charged up and has good voltage (more than 12v)
On the left side of the barrell is a little cover over the power valve actuator pulley. take this off and replace the nuts that hold it on. Then start it up and around 8300rpm the pulley should rotate about 20 degrees. If it doesn't then the servo is crook or the cable broken.
If all is good there then it's a bit more detailed as the power valves will have to come out for complete checking and calibration. This should be done around each 5000km anyway, as they're prone to crapping out.

Also, I'm assuming it has good compression. Does it idle OK? If so, then it's unlikely a massive loss of compression has occurred to give you your troubles

[ital916]

powervalves. If there is a lull at 7-8000 and no power after that I would seriously be looking at your powervalves.

[EUPHORIA]

the guy borght it off was acturally a mate and he change the power valves bout a month ago and change the piston.

it does idle fine.

someone told me it could be the carby? thats why its not reving out.

[Jeaves]

unbolt the inspection plate for the powervalves.....make sure there are no screws/clip/springs floating around.

[georgie]

hey Euphoria, if you need a hand to figure out how to get to the powervalves/check the timing of them, shout out. I've got pretty good at it over the last few months. Wher abouts in Auckland are you?

[oyster]

There's nothing worse than pulling something to bits to find it was something really simple. So do the easy bits first. Voltage, servo, cables THEN check the valves. That they have been worked on recently is no garanteen they're OK. The original screws that hold it all together fall out VERY quickly sometimes. We now fit good quality Socket head cap screws every time.
M5 x 12mm Grade 12.9. A wee drop of Loctite too. Run a bottoming tap down the thread to get that extra few mm of thread needed for the 12mm long fastener.

With the cover off the front of the barrell the heads of the power valve stems should come out about 2mm below flush with the housing. (When fully open) To open the valves with the engine not running, turn on the ignition and earth the bullet connector wire right next to the neg terminal of the battery. This "jumps" the servo to nearly full travel. Adjust the cables to get this setting and make sure finally there is no backlash.

[quallman1234]

Hey mate,

Download the manual for the RG150 and check your powervalve's like oyster said.
You will have to remove the raditor to get in there but this only two bolts and two hose clamps and shouldn't take long to do.

Here is the link for the RG150 Manual Directory, the info is in the pdf file "Engine" but i recommend you download them all if possible.

http://zballantine.com/RG150/

RG's are fairly simple engine's and you shouldn't have too much of a problem doing it your self, if in doubt ask on here tho.

Good luck!

P.s Your have a massive increment in power once the valve's are sorted so its well worth doing.

[EUPHORIA]

ive download the manual thx for that.
and ill atempt to check all those things today.
good time to work on the bike cant go riding in this weather.

i live in west auckland.

thx for all the info back.
need as much as i can get. :]

[Honda worshiper]

I know this thread is 3 years old but I'm having the same problem. My RG seems to loose power over 8500 rpm. Should I try and adjust the power valves myself according to the manual or just take it in and get a mechanic to do it. I was told the power valves should be replaced with age as they can drop into the cylinder head and stuff the motor. My bike has done 44000k's any advice?

[FruitLooPs]

Download the service manual, thats a stack of KM's on an RG150. Mine had a bit more than yours and ended up needing custom p/valves made by Oyster because the powervalve bores were worn allowing the valves to rattle and snap the stems prematurely (as I found out with $700 OEM set that lasted only 9months or so!). The downside to these is they were single stage instead of 3 stage sliding, so there was a gap in the power - much more robust but they didn't cover the transition from no powervalve to fully open as smoothly (more on/off) at least it would rev out fully! New barrels back then were $$$ and I can imagine these days its even more, and add to that the fact you'll be on an oversize piston so thats a new piston + rings if you did need a barrel.

Go through the stuff listed above, Oyster has serviced, fully rebuilt and maintained dozens of these bikes literally.

Like has been said, once when riding mine down to wanaka after a prolonged period of high RPMs I lost power same as yours. I was sure I'd damaged yet another set of p/valves, checked the p/valve actuator and found the screw had backed out stopping them from opening - easy fix!