83 RZ350 hits a wall at 7000rpm

[Warnzie]

And just another thought, the fuel petcock vacuum hose to the RH carb, I have used clear / pink vent hose for this - does it need to be specific vacuum hose?????

[silverstrom]

Any hose that fits tightly and doesn't leak is fine.

[Warnzie]

So, anyone got any thoughts why with the baffles in (stock 83 exhaust) my bike won’t pull at 7k rpm but without them it will run fine? Have cleaned them 2 times and it seems it does t make a difference?

[silverstrom]

So, anyone got any thoughts why with the baffles in (stock 83 exhaust) my bike won’t pull at 7k rpm but without them it will run fine? Have cleaned them 2 times and it seems it does t make a difference?

It suggests the baffles are not the problem, but removing them helps.

Have you checked the rest of the pipes? If not, now is the time to pull them and make sure they are clear end to end. You'd be surprised to see what comes out of pipes. Many ways to clean them if needed. Caustic Soda, other chemicals. A steel wire and and a drill work wonders. Splay the end of the wire out and attached the other end to the drill. Insert the splayed end into the pipe and fire up the drill. Hold on tight. Video here https://www.youtube.com/watch?v=6mVFAmLBimA

[kpke]

A steel wire and and a drill work wonders. Splay the end of the wire out and attached the other end to the drill. Insert the splayed end into the pipe and fire up the drill. Hold on tight. Video here https://www.youtube.com/watch?v=6mVFAmLBimA

I have done this many times. Wear leather gloves AND a face shield. One time I pulled it out on accident and it whipped up and hit me in the face. Could've been much worse.

[Warnzie]

Getting chambers burnt out this week so will update to see if this helps to sort out my problem

[Warnzie]

So here’s an update, got the chambers burnt out - yep plenty of carbon. Also found the slides weren’t lifting all the way as well so sorted that. Bike still has troubles at 7k where it struggles to rev. Took snorkel out and was marginally better. Did a plug check and one side was richer than the other. Raised the clip on the rich side which got me a perfect beautiful brown on both sides. She will rev past 7k now, but not with the urgency it should be. At times it will rev cleanly and other times not. Have checked the vacuum on fuel tap and it perfect. I have now changed the vacuum hose to proper - specifically for vacuum to see if it makes a difference. Other than that my next point of call is too remove my baffles to see if that makes a difference. If so my main jet might be too rich? It’s running the stock 240 with all original running gear. Would taking baffles out lean it out dramitacally???

[Darrell]

Sometimes it can be a tedious process, especially if there are more than one problem. Sounds like you're winning!

[Warnzie]

Ok, so a update so here we go...half throttle she holds back a bit, as in doesn't want to accelerate - like someone putting rear brake on. On WOT she would rev out, but not with the urgency and speed it should. So I decided to run without baffles to see if it made a difference. Slight but still got that brake feel at 1/2 throttle but, when she hits band oh my she takes off and just wants to keep reving. So, it would seem my needles are either rich or lean I'm thinking as a test, could put the snorkel back in and see if it gets better. If so we at least know we were running a little to lean...if it gets worse I know I need to lower the clips by 1 to get richer???? I’m all good at WOT with the baffles out, she absolutely screams now up top. I did do a plug check after giving her 1/2 throttle for a few seconds before pulling her up at the ignition and to me both plugs look rich to me. Tried posting the pics but can’t get them small enough

[Warnzie]

managed to sort it out, here are my plugs - bit rich I think. Reckon I could go up a notch (raise) on the needles by 1 clip and see how we go

[silverstrom]

Checking the end of the plug is not a good indicator of proper fueling for a 2 stroke. You really need to do a plug chop if you want accurate results.

This is what you need to see viewtopic.php?f=1&t=16205&p=163081&hili ... op#p163081

[Warnzie]

I raised the needle clip up 1 notch on each side and just as I thought, runs brilliantly through mid range now. Was definitely running rich which held it back when accelerating. So I now have LH cylinder at notch 3 and RH cylinder at notch 4 - this makes a very equal plug burn on both cylinders. I would dare say my main jet - standard at a 240...or is it 230 is rich as when coming on from needle to MJ if given a boot full will hold a tiny bit back but at the present tune it gives a good balance of performance and reliability

[Evans Ward]

Glad it all worked out for you! Now, ride and enjoy it….