Cant get past 8,000 rpm??

[jasonkoscho]

I have a 2001 sv650s (US)

To get to it; I cant redline above 2nd gear. In 1st and 2nd, I can redline with no problem. But in 3rd and beyond -- I hit a wall at 8,000 at about 80mph at full throttle. If i shift to 4th and give it full throttle, the rpm stop at 8,000 but my speed with increase VERY slowly.

WHAT I'VE DONE SO FAR:

1. Ran SeaFoam through with no change.

2. Replaced and cleaned both spark plugs. I found lots for corrosion and brown build up on the front plug. Looked very rich. The rear looked fine.

3. Installed new jets and shimmed: 150 main & 17.5 pilots with 2 shims. When I took the carbs out, i noticed the front needle and slide was sticking. It felt "gritty". With the float apart and new jets installed - i noticed some sort of build-up on the gaskets and on the slides, so i cleaned the slides off and they were smooth again.

4. Checked the air filter. Its stock, and looks clean. I may just change it for ease of mind.


After all this - still the same problem. After scouring through the posts here, the most common thing seems to be rust.

IM GOING TO TRY:

1. Sync the carbs
2. Adjust the A/F screw (2.5)
3. Replace Fuel Lines (in case there is varnish)
4. HEET to the tank
5. Seal the tank in case of rust

Any other thoughts? Im lost, It sounds and feels great in 1st and 2nd. But i hit a dead wall at 8,000.

What speeds are you guys able to hit in what gears? Just so I have a comparison. And is it easy to redline? Should it pull more at the top, bottom, or the entire way through?

Thanks. I REALLY appreciate any thoughts.

Jason

[Dangerous Dave]

Did you put everything back together and sealed properly when you did the filter and jets?

[jasonkoscho]

Yup.
Everything is back up and running. Still rides the same.

[Paul the 6th]

erm, in 6th gear on the motorway, the engine revs are 2000 behind whatever speed you're doing, so at 80mph, the revs show 6000rpm, at 100mph its 8000rpm and so on.

Is there any chance it could be restricted? I've not got any real mechanical experience or knowledge with restrictors but I've heard people talking about the way they limit the top end and the bike "runs out of steam" etc...

I'm sure one of the experts will be along shortly to tell me off :)

[jasonkoscho]

Hey - at this point im open for anything. I wasnt familiar with the restrictors so i did some googling to find out what it was. and, correct me if im wrong, but it seems the restrictor is if the slider has a hole in it? is that right?


like here: http://forums.sv650.org/showthread.php?t=62081&highlight=remove+restrictor

but it still wasnt entirely clear.

thanks again!
jason.

[Biker Biggles]

Are you consistantly finding issues with one plug?I notice you said the front looked rich?Have you cheched the choke plungers,especially the front,as one cylider running very rich would cause poor running like this.

[jasonkoscho]

I only checked the plug once, when i replaced them. That was about 1 month ago. Im not familiar with the choke plungers. What and where are they located? What would i be looking for on the plungers?

[Biker Biggles]

If you follow the choke cable from the bars it goes into a splitter between the frame and front cylinder and a cable goes to each carb.These are held in place by a plate with a screw.Undo the screw and pull out the cable which will bring out the plunger.
All this lot including the cables can sieze up causing the chokes to stick on and poor running.The screws are prone to rusting in place,hence they get left for long periods,especially the front one.

[jasonkoscho]

I took the carbs out and put in 140 mains and made sure that everything was clean and secure. Fuel lines look good. Springs and needles look good and smooth. Then checked the choke plungers -- and as far as i could tell, they looked good. No rust. The springs looked a little bent, but they were in there snug.

I then took out the spark plugs. Rear looked good. But could be lean. Then the front... Its black. The boot also has some corrosion. I already replaced them about 2 months ago and noticed it then too. But this confirms that my front cylinder is running VERY rich.

Here are some photos. Let me know your thoughts and how I can fix the front cylinder to run better.

REAR:
http://nightcapchronicles.com/jk/sp_rear1.jpg
http://nightcapchronicles.com/jk/sp_rear2.jpg
http://nightcapchronicles.com/jk/sp_rear3.jpg

FRONT:
http://nightcapchronicles.com/jk/sp_front1.jpg
http://nightcapchronicles.com/jk/sp_front2.jpg
http://nightcapchronicles.com/jk/sp_front3.jpg
http://nightcapchronicles.com/jk/sp_front_plug.jpg

You can see there is some rust in the front boot too. The rear boot looked fine.

Thanks again. What can i do to resolve this? jets?

[Stu]

Sounds exactly like the bike is restricted for learner riders to 33 bhp. This is very common in the UK but I was not aware of the same requirement in the USA. Do you have that law anywhere in the US?

[Paul the 6th]

california mabye? they've got alsorts of wierd & wonderful laws

[Dangerous Dave]

A restricted bike will still go past 8000rpm, it feels a little gutless when compared to the full power SV, and it does not effect certain gears.

[yorkie_chris]

I reckon front choke plunger, if not that then float level. Pull choke plunger out, blow hole out with compressed air, carb cleaner the plunger, put it back with grease on the spring. Check the cables are moving freely and are seated in their places correctly! If they are not seated right choke will be held open, this is very common after removing and replacing carbs.

Also while you're in there with airbox off, check the sliders move up and down freely, and move equally when you rev the engine.

[jasonkoscho]

I took a look at the sliders - the front was slow to close. I opened it up and cleaned the rubber boot and realigned it - and it seems to be snapping back just as fast as the rear. I also checked the plungers and as far as i could tell, they looked fine. Although, i wasnt 100% sure what i was looking for. No rust or anything. The spring looked a little bent, but they both snapped in there pretty tight. Should there be any movement or motion to the plug? does it slide?

thanks again.
jason.