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Former Member
deleted
4 Posts |
 Posted - 29 Jul 2005 : 04:20:30 AM
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Hi Guys,
Havent had any experience with 2 strokes before and brought a rz250 for a good price about a week ago, it keeps fouling plugs (in like a 15-20min ride) and doesnt idle.
The guy I brought it off said he had changed the rings about a year ago, rode it for a few months then its been sitting for the rest of the time.
Im running premix at 40:1
I've pulled carbies off and cleaned them.
As suggested by yamaha pulled carbies and exhaust off and put petrol in the cylinders and blew it out with compressor as they thought there may have been some gunk in the cylinders (made it run a bit better but still fouls the plugs)
Checked compression its 90psi on the left and 95psi on the right. (The guy at yamaha told me ideally it should be 110psi and above).
Spark seems to be fine
Also i took it for bout a 5min ride the other night went into a mates place come out bout 2hrs later started it up and she revved to 9000 straight away, turned it off straight away, tried again same thing happened, decided to ride it anyways and it stopped 2 mins later at the lights and wouldnt start
Any suggestions would be greatly appreciated
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Allan
Site Moderator
National
599 Posts |
Posted - 29 Jul 2005 : 07:17:18 AM
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 check crank seals, to drive priamy side and center crankcase to gear box oil..
check level of gear box oil and see if it changers ..But sounds like here the problem lies..
this is a general cause of spark plug oiling!! |
Allan Greening |
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matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 29 Jul 2005 : 11:30:41 PM
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what plugs are you running?,not too cold?,40-1 premix,we take it the oil pumps' disconnected!!,2strokes burning gear oil tend to smell really bad,generally r/h pipe/plugs oilier?,whats your float levels like,not too high,or flooding?,re 9000 revs,check inlet manifolds balance pipe,could be loose,or carby tops coming loose?,resellit,go buy a 4 stroke? ,good luck, |
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Former Member
deleted
4 Posts |
Posted - 01 Aug 2005 : 01:20:32 AM
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Hi,
I'm running B9ES plugs which is the right plugs for the bike.
Yes the oil pumps been disconnected.
The right hand plug is oilier but it doesnt smell that bad just smells like normal 2stroke smell.
Balance pipe is fine, top of carbies tight.
Float levels fine.
Looks like i'll be pulling it to bits.
Thanks for your help |
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matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 01 Aug 2005 : 11:38:46 PM
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| Mashall,just pop the clutch cover off 1st ,dive into rh crank seal, check it out or just replace it before dismantling whole motor?,has like Allan suggested,the gearbox oil level dropped?,9's a bit cold unless your'e flogging the ring outer it!!,(which obviously your'e not coz they foul up? ),good luck, |
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Former Member
deleted
4 Posts |
Posted - 05 Aug 2005 : 04:29:50 AM
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Oil level seems fine.
I will check the crank seal over the weekend.
The b9es plugs are what is specified for this bike. Do u suggest using a different plug?
It was running good last nite both cylinders firing. But i was riding for bout half an hour and ran out of fuel it had bout 4Ltrs of fuel in it, so its obviously running rich.
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Edited by - n/a on 05 Aug 2005 7:52:22 PM |
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matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 05 Aug 2005 : 11:06:58 PM
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| ok 1/2hr running,say 50/60k's?,about 4 ltrs = say 14ks /ltr,not sure what's concidered ok for RZ250's(lurkers feel free to jump in here?),maybe it's just needle positions?,all the way up would still run but guzzle juice & load plugs up?,leave 9's in ,if they handled 1/2hrs running,not much point in trying 8's,(unless it's all slow/medium pace riding?)stick your thumb over gearbox filler hole with motor running ,feel for pulse,no sensation of pressure pulse means rh crank seals ok,(but i think it's ok anyway coz level hasn't lowered!),try comparing jets,sometimes they get drilled out/modified with std numbers left intact,(disinformation?),again my 2bobs worth, |
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yamaman
Level 2 Member
Western Australia
44 Posts |
Posted - 06 Aug 2005 : 03:51:44 AM
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Are exhaust pipes fulla ****e? They gunk up pretty bad, especialy if its not been running right! Power valves can get stuck also.
Simple stuff first, check exhaust, air filter, needle position, jet sizes, power valves, leaking base gasket/manifold (spray aerostart on it while running) ring gap, piston, bore. When new rings were fitted they might not have been gapped properly if it was a home mechanic, or it might have needed new pistons or a rebore!
All just guessing mate, good luck with it! |
Beer makes you feel like you should feel when your not drinking beer |
Edited by - yamaman on 06 Aug 2005 11:28:45 AM |
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Former Member
deleted
4 Posts |
Posted - 06 Aug 2005 : 6:36:12 PM
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Put my thumb over the oil hole and felt no pressure or pulse.
I pulled the silencer out and gave it a good clean the other day and ran the bike without it on for a little while to try and clear it out.
Air filter is brand new.
Needle position is set to spec. (3)
Main jets are different to stock, left is 180 and right 140, stock are supposed to be 155 (not sure if they are changed because its been changed to premix but i would expect them to be the same)
Pilot jets are stock 25
How do I check the power valves? I have got a workshop on order but thats a little bit away prob mid week.
Im taking the guys word for it that the pistons and cylinders where in good order and it didnt need to be rebored and that it was gapped properly.
Sorry but what is the base gasket Im guessing its the gasket between the cylinders and the block if thats what you call it.
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yamaman
Level 2 Member
Western Australia
44 Posts |
Posted - 06 Aug 2005 : 9:02:35 PM
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Hmmmmmmm, thats a massive size difference between the jets! As Mick said, check if they are said size. Find a piece of wire that fits nicely into 1 jet (dont force it), and check the other to see if 1 has been drilled. I'd say though that'd be a good starting point to get them right.
Base gasket is base of cylinders to crank case.
I think when you first turn on key, power valves should open and close, you should hear the servo motor working for a cpla secs. You should be able to see this happening on the cylinders (elec motor pulls cables opening, closing p/valves)
If its not working, wire them into the fully open position. But get the jets right first! |
Beer makes you feel like you should feel when your not drinking beer |
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matcho mick
Advanced Member
New South Wales
570 Posts |
Posted - 06 Aug 2005 : 10:33:03 PM
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logic tells me the 140's drilled to match the 180  ,(unless 180's compensating for lh crank seal sucking air ?)best bet is to obtain/borrow some std mains & try them,did running without the baffels have any effect on motor,rev freer?,how much carbon build up was on them?,usual practice was to decoke with oxy,(slower method is caustic bath!),if the motor idles reasonably your base gaskets are probably ok,(also compression too),cheers |
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racer7
Level 2 Member
67 Posts |
Posted - 01 Oct 2005 : 5:33:48 PM
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And.....
It's good as new or broke?
I bouht, no I didn't, I bought an RGV Race Bike. I believed it should have run better. Got the Workshop manual and compared jets to what should be in. The pilots were correct. Nothing else matched the book. Mmm, OK, compared to the price of the bike, a few standard jet sizes is small bickies. Guess what, goes like I thought it should!
Perhaps the factory actually knew what they were doing. In the past million years, I've spent a couple of house prices on engines fettled by Guru's. A fool and his money Eh?
racer7 |
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acotrel
Advanced Member
Victoria
2147 Posts |
Posted - 02 Oct 2005 : 01:28:26 AM
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I'd replace the crank seals anyway, if you've got any doubts about them. Set the carbies to the manufacturers spec. The settings might be slightly rich. If you're going to race it, you can lean it off later, (very carefully). Check float levels in the carbies. Get your ignition system checked, by someone qualified to do it. Sometimes a faulty ignition can make the plugs look like you've got a jetting problem. The oversize jet in one cylinder is probably an attempt to richen up that side due to a leaky crank seal or a faulty ignition.
You should be able to rotate the power valve spindles (check). I believe on the RZ250, the power valves are cable operated.
Two strokes are great when they're set up right. An RZ250 is better than any RD250 or RD250LC ever was. |
Is your machine authentic or merely eligible? |
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acotrel
Advanced Member
Victoria
2147 Posts |
Posted - 02 Oct 2005 : 7:12:41 PM
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| I reckon RZ250s and RZ350s should be allowed to run in period 5, also X7 Suzukis. The smaller classes of Period 5 with the TZs and RDs is just what C grade racing was in the 70s when everyone had RDs. Where are they all now? |
Is your machine authentic or merely eligible? |
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cammo_17
Level 1 Member
Tasmaina
1 Posts |
Posted - 16 Sep 2006 : 12:46:14 PM
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hi i need to know how to adjust the power valve cables on my rz250 89 model. Can anyone help please  |
cblake |
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redline
Level 1 Member
South Australia
1 Posts |
Posted - 19 May 2009 : 1:29:30 PM
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| I've got 2 RZ 250's as track bikes No air cleaners using 240 main jets and they boogie One has the power valve locked on as it's knackered and I can't tell the difference Is the valve not helping at full throttle or is it my imagination ? |
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