RG150 problems

[enth]

Hi all,

So I took my beloved RG150 up SH16 yesterday and about 3km out of Wellsford it decides to die. So I check the gas, full. Two-stroke, full. Can't think of anything else I decide to get it going again and it's back but it's doesn't seem right. Get it back to Auckland and the whole way back it feels like it's about to die.

I have to keep the revs up to 8,500 or more to make it feel like it wont die.
It sounds dull, almost like there is something wrong with the exhaust.
Doesn't have the same acceleration as before.

I've been running Shell 95 and Semi-Synthetic oil since I got it.

Any one come across this problem on 2-strokes before?
My dad reckons the jets need to be cleaned but I'm not so sure on that, thought I'd ask KB forums.

[Str8 Jacket]

First things first, change the spark plug and then try again. It may or may not solve the problem but its a good start and will do nothing to harm the bike... There is not a hell of alot of things that can go wrong with an RG so give the bike a good looking over and cleaning. Two smokers have a tendancy to get quite grubby! :devil2:

Also, decoking is fun and wont hurt the bike if done properly either. If you dont know what you are doing get someone who knows how what they're doing to help.

[MDR2]

And while you're at it, take the power valve cover off and just make sure everything is where it should be.

might pay to check the oil pump is set correctly too.

[SMOKEU]

Light a big fire in an old drum and throw the exhaust in for a few hours.

[enth]

Also, dechoking is fun and wont hurt the bike if done properly either.

So remove the choke and leave it off? What will this do?


And while you're at it, take the power valve cover off and just make sure everything is where it should be.

might pay to check the oil pump is set correctly too.

I'll have a look into the power valves, I think this is where my problem is. When I get around 8,500 - 9,000 rpm the bike opens up, like really opens up


Light a big fire in an old drum and throw the exhaust in for a few hours.

Rather take a flame thrower type thing and burn the build up out and then knock it out with a rubber mallet :P

[Kiwi B]

Power valve wouldn't make it die - it just won't hit the power band around 9K RPM - should still run mint under that.

Sounds more likely to be fuel related - if its hard to start and you have to keep the revs up to keep it running it probaly does have some shit in the pilot or main jet and is running way too lean. Replace the plug, check for a strong spark when you kick it over - if it does, take it for a ride, if it still runs like shit time to clean the carb.

Good luck

[T.W.R]

Rather take a flame thrower type thing and burn the build up out and then knock it out with a rubber mallet :P


If you've got access to an acetylene torch & an air compressor with an air gun use that..... get the buildup at the manifold end of the exhaust burning with the acetylene then once the gunk is burning/smoking well just feed it some air with the air gun and once it's really going it'll burn by itself. When it's done just shake & tap out the ash and give it a good blow through with the air gun again to dislodge any other remaining ash.

[enth]

Sounds more likely to be fuel related - if its hard to start and you have to keep the revs up to keep it running it probaly does have some shit in the pilot or main jet and is running way too lean. Replace the plug, check for a strong spark when you kick it over - if it does, take it for a ride, if it still runs like shit time to clean the carb.

Good luck

Where is a good place to get the carb checked over/serviced in AK, just incase it is the carb. ;)

Thanks.


If you've got access to an acetylene torch & an air compressor with an air gun use that.....

I would if I had an acetylene torch. Would SMOKEU's way work, the whole barrel of fire and exhaust in it? I thought that way would melt metal :crazy:

[T.W.R]

I would if I had an acetylene torch. Would SMOKEU's way work, the whole barrel of fire and exhaust in it? I thought that way would melt metal :crazy:

you'd be right.....but it wouldn't so much melt the metal of the exhaust but deform the shape of the exhaust. Centralised heat in key areas of the exhaust would do damage.

The best way is slow burning of the carbon build-up in the exhaust not extreme shock heating

[Kiwi B]

Don't take it to a shop - they will tuck you hard - its a recession - Troll the internet for a manual or use the attached carb blow up (pretty sure your bike has a Mikuni TM28mm if not find the right one - www.sudco.com) and pull it off the bike and apart yourself. It is the best way to learn and that way if it happens again its no drama.

Even without a manual it is not a hard job - just take your time and even take photos as you go so you know where things go. You will need to unscrew the air/fuel mixture screw (no 49 on diagram), count the number of turns to wind it in untill it bottoms out (gently). When you put it back together do the opposite - should be mint. Just blow all the jets and small passages out - CRC will do the trick if you dont have compressed air. Keep your work space clean and put it back together - simple in a sort of complicated way:2thumbsup

Seriously it is not as hard as it sounds - give it a go - worst case you can take it to a shop for them to put back together - you still save money as it is off the bike and clean :banana:

[Kiwi B]

Just because I am a 2 stroke fan and all 2 strokers should know there bikes - heres a linky

http://www.kiwibiker.co.nz/forums/showthread.php?t=26069

Good luck

[enth]

I have all the Chapters of that manual except Chapter 5. I left a post on that thread with my e-mail.

Thanks for your help Kiwi B.

[MDR2]

I'll have a look into the power valves, I think this is where my problem is. When I get around 8,500 - 9,000 rpm the bike opens up, like really opens up


If its hauling ass at around 8500 then it's not likely to be related to your current problem. Sounds like fueling like everyone else is suggesting.

However, i'd still recommend you check the valves condition. make sure the screws are tight. if not, get some loctite and nip them all up

[Ixion]

If you've got access to an acetylene torch & an air compressor with an air gun use that..... get the buildup at the manifold end of the exhaust burning with the acetylene then once the gunk is burning/smoking well just feed it some air with the air gun and once it's really going it'll burn by itself. When it's done just shake & tap out the ash and give it a good blow through with the air gun again to dislodge any other remaining ash.

Before doing this go round all the neighbours and tell them NOT to call the fire brigade when they see great smokings from your place. DAMHIK

[enth]

Had a look at the reed valve and the jet. Jet seems to be clean, my word it's tiny though. The reed valve has 3 reeds on each side and on the one side they don't lie completely flat when taken out. Maybe about 0.2mm. Would this maybe be my problem?

Oh and why would I take the choke off?

[koba]

Had a look at the reed valve and the jet. Jet seems to be clean, my word it's tiny though. The reed valve has 3 reeds on each side and on the one side they don't lie completely flat when taken out. Maybe about 0.2mm. Would this maybe be my problem?

Oh and why would I take the choke off?

Thats a typo, She would have been meaning to say "decoke" which is cleaning the exhaust out.

[SS90]

To the original poster.

STOP NOW.

While I realise that everyone who is posting here have good intentions, the simple fact is that it's highly risky to go making assumptions particularly via the internet.

From what you describe, (in my professional qualified opinion) it's not the carb.

It COULD be the reeds, but, you suggest that there is a 0.2mm gap in the reeds, (but I assume there are no splits etc), then that will be OK (the negative pressure in the reed block will close them)

"Decoking" (on modern two strokes) is not like it used to be.

FFS do not put your expansion chamber in a fire. (Sheesh!):weep:

If you really want to fix this problem with-out taking it to a workshop, (though I recommend that you do) then think about this.

The archillies heel of the RG150's is the power valve.

The power valve is located on the font of your cylinder, above the exhaust.

I suggest, due to your symptoms, that this is the problem.

If you remove the fairings, and look at the font of your cylinder you will see a rectangular cover, secured by 4 screws.

Remove these screws.

A small amount of burned black oil will come out when you do, but don't fret, it's ok.

under this cover is the power valve mechanism, and in all likely hood, the power valves will be jammed open/damaged in some way.

If this sounds a little technical/difficult, perhaps a shop wold be better.

It may save heart ache.

[oyster]

It could be partial seize, which has damaged the bore and piston enough to
drop the compression. This will make the motor a flat and gutless slug.
Power valves falling to bits is common, and one type of failure has the valve(remains) wearing way at the edge of the piston. This is a cause of the seize (above). It's amazing how well they go with stuffed power valves in this state as well. If you take off the cover and lots of bits come out to meet you, then you need a thorough power valve service, and I modify them to give the best future chances. In exteme situations I fit new single stage valves, lapped to fit the (usually) knackered bore they live in. These are way cheaper than originals and way better as well. I do about 1 barrell assembly a fortnight for people all around NZ so if you need that service PM me for details.

Or it could be fuelling. As many have said, thoroughly clean all jets including the float needle. The taps are prone to blocking so take it out and clean well. Water easily gets in the tank causing big trouble too, so clean and dry the tank. (But it doesn't rain in Auckland does it?) Check the cap breather is not blocked. One quick way to check re fuelling is when a bike is giving such symptoms, turn the choke on. If it momentarily improves things, fuel is a dead ringer for the first place to look

[Kiwi B]

If the bike runs mint over 8500rpm and flat below then the power valve is stuck open - if the bike runs mint up to 8500 then feels flat above the power valve is stuck closed. Which is the case????

Not sure about the rg150 but most power valves have a clean cycle when you turn the ignition on - easy as you should hear it rotate. If it doesn't you can always check that the solenoid/motor works as you rev it to over 8500rpm - just blip the throttle - you should see it rotate/move - if not, it is stuck or the solenoid/motor stuffed.

I am still not entirely convinced it is the power valve though - it wouldn't have died if just the power valve was stuck open UNLESS you expected it to be able to pull a high gear at low revs. It would feel like it has absolutely no power below 8500rpm but should still run bit like a car with a blown head gasket - runs but no power.

I wouldn't bother with the carbon in the exhausts at the moment - get it running mint first. When you do, get a hot air gun, that way the heat is controlled and the oil/carbon will starting burning and the air keep it burning hot enough to burn the carbon.

Easy things first. 1.check the spark & spark plug 2. check the fuel 3. check the power valve is rotating. 4. clean the jets/carb - if it is still not running then take the exhaust off and check for signs of a partial seizure.

[enth]

If the bike runs mint over 8500rpm and flat below then the power valve is stuck open - if the bike runs mint up to 8500 then feels flat above the power valve is stuck closed. Which is the case????

It's like it's stuck open. Nothing wrong with carb or reed valves.

When I took off the powervalve plate some stuff fell out which was attached to the one powervalve but haven't managed to get the three screws off yet to inspect the powervalves so can't be 100% certain as to it's them that's causing the problem. Have to wait for the impact driver to arrive before I can take them out. But as to what fell out, it looks like a bracket that holds the powervalve actuator thing (broken in half, will get a new one machined when I get to a lathe) and a spring.

What the bracket looks like

http://www.iforce.co.nz/View.aspx?i=k1fsc4st.jpg

What the bracket is meant to look like.

http://www.iforce.co.nz/View.aspx?i=4r1sm3xi.jpg

Should I make it out of aluminum which is what I think it is already or make it out of something stronger like stainless steel? It doesn't rub up against anything so it shouldn't matter, right?

[enth]

Yeap so it's the powervalve. MUNTED! Anyon have any ideas if I can get an engineering shop to make me some? Would be expensive but cheaper than ordering from Japan.

PS. Does the RGV150 use the same engine as the RG150, with powervalves etc...?

[gwigs]

Light a big fire in an old drum and throw the exhaust in for a few hours.

Remember to remove bike from exhaust first though eh !:whistle:

[SMOKEU]

Remember to remove bike from exhaust first though eh !:whistle:

I "forgot" to mention that part.

[oyster]

The broken bit is called " SPACER, exhaust valve Part No 11263-08011"

It's common to see them broken. I make new ones from mild steel, way better. Making them requires a bit of care, the hole has to exactly in the right place so I have a precision drilling jig to acheive this, plus the hole is a very strange size, so I've ground a special drill diameter to suit.
The offer is still there, I can service and repair the whole arrangement. Send the barrell and head attached as a complete assembly. If the power valves are a write off I'll fit new ones at around $200 for the valves plus fitting. Way cheaper and better than the originals. PM me if interested.

[enth]

Oyster, I gave you a PM.