Emet

Picked up a year 2000 SH with ~32k miles. I knew it had some issues when I bought it, figured I could get them sorted as I am somewhat mechanically inclined.

Issue 1. Wont pull past 6.5k RPM, Found plenty of discussions on the forums on this sort of issue. I'm figuring this is a jetting issue (main jet?) but haven't had a chance yet to verify what jets are currently installed.
Issue 2. Pops, bangs, farts on decel (kinda cool, gets old fast). Figuring this is also a jetting issue (pilot jet?). It also pops a bit on idle especially when its cold.
Issue 3. Misfires below ~3k RPM. Power will momentarily cut out and engine makes a "tick" sound. I think it could be a TPS adjustment issue, not sure yet. Runs great from 3k rpm to 6.5k though XD and there's been plenty of fun even in that limited range.

Ordered some new spark plugs, new air filter, and some other odds and ends. Fresh 93 pump gas in the tank. Already have taken apart the carbs and cleaned things up (forgot to check the jet sizes when I did so). Also have already had the vacuum line into the wrong part of the petcock which I considered my initiation into the SH world. I previously owned a 2007 Kawasaki Ninja 250 and then a 2008 Kawasaki Ninja 500, and now the mighty SH. Funny how the CC's doubled each time

Its got aftermarket Two Brothers exhaust (which desperately need to be repacked) but that seems to be the only mods as I can tell so far. Any advice or links to other discussions is very much appreciated.

Thanks.

Wolverine

1st off, welcome to the forum!


Did you very carefully inspect the rubber carb diaphragms? A little hole or crack can cause problems, and when it comes to your issues, a very thorough carb clean and inspection is very important. Remove the petcock and inspect/clean/rebuild. Sitting unused for long periods w/o proper precautions can lead to headaches.

xeris

2nd on the diaphragms.
Any history of the bike before your ownership?
Have you had the valve covers off to check the cam timing?

Emet

Hey guys, I super appreciate your responses to my thread here, and even though I was feeling some despair over this purchase, I have hope it will run correctly again and that I CAN DO IT :P
I've got a list of things I will check next time I have the bike apart. I do not have a garage, and its winter, so I have the bike in storage at the moment. Might find some time to work on it this weekend and I will run through a list of possible causes for my problems.
I will give the carbs another blast with cleaner and compressed air and check what jets are installed, will also inspect carb diaphragms with a light, and inspect the fuel petcock.

The only history I have on the bike, is that "it ran great in the fall" oh and "the previous owner did a custom paint job... it looks black but its got a bronze sheen in the light". So theoretically something like dirty carbs or a crack/hole in one of the diaphragms would make sense since it was sitting over the cold winter. Unfortunately, I don't know for sure how honest the PO was.

And no, I have not checked the cam timing but it is on my list. Will get back with a report ASAP. Thanks again

Emet

Alright thread buddies, some interesting results and conclusions have formed over this past weekend. Verified the carbs are as clean a whistle, jets too. Its got a 48 pilot jet and 175/178 mains (175 front, 178 rear). Rubber diaphragms in the carbs are without any holes, cracks, or tears (checked with a bright light in a dark place) and installed correctly. Fuel petcock looks good. Put it back together, put the vacuum line where its supposed to go, and went for a test ride... still have the same issues.

New information: Honestly thought my temp gauge was broken as I have never seen it move... until now. I had the bike sitting, idling, playing with the throttle and whatnot, and I see the temp gauge starts rising. The gauge gets to halfway and the fans kick on, and the temp does not rise above that halfway point. Out of curiosity I leave the parking lot and practically make it to redline with no stuttering while the bike is still warm. As I go down the road, the bike cools down almost instantly to where the needle falls down to the C and the issues resume. I pull over again and let the bike warm up, and try to ride below 3k rpms... no more misfiring, runs like a dream. My conclusion is that there is a malfunction in the thermostat making it so that my bike is cooling even when it needs to stay warm and causing the running issues. This would make sense why the PO didn't have issues with it because he had only ridden it in warmer temperatures and then these issues arrive in the winter. I am going to check the thermostat next chance I get, possible this week, and order a new one from Rocky Mountain. Will post back with results. Really hoping this will solve my issue!

PS I have been riding in the mid to low 40's for testing purposes

Wolverine

Order a new radiator cap too. Just because.

Emet

So far:
- New air filter
- New spark plugs
- Carb + diaphragms inspected
- Timing checked and MCCT fitted
- Fresh gas in the tank
- New thermostat

Still the same issue occuring. Will be searching the forum for other possible causes.

Wolverine

Adjust the TPS @ 475-500ohms.
Are the little foam filters for the carbs (in the airbox) intact?

So the bike won't rev past 6500 while riding, normal throttle or WFO?

xeris

Will the engine rev past 6500 rpm with no load?

Emet

Foam filters in the airbox are in fine condition.

Okay so if am SUPER careful with the throttle and move it extremely slowly it will go above 6500 rpms but not very far above that. As soon as the throttle moves 1mm too fast it hits the wall hard. It will go through the RPMS fine on the stand.

Something strange I noticed is that the spark plug caps are not snapping into the top of the spark plugs like they would normally. In fact, they would not even attach to the new spark plugs at all. I looked at the old spark plugs and they had the tops unscrewed. Kinda hard to describe in words what I'm talking about but on the top of the spark plug there is the piece which the spark plug cap would interface with and it was stuck in the cap, unscrewed from the plugs themselves. Didn't know what to make of it at first but maybe who ever changed the spark plugs last did something funky. This could very well be causing me the issues if the spark plugs just aren't getting enough current as if the coils were bad. I will look into this sometime this week and report back. If that doesn't make a difference then I will recheck the fueling lines/system. Thank you for your guy's input.

xeris

I don't think that the spark is the problem.
If the engine revs past 6500 on the stand and not under load, I would consider another look at the cam timing.

Wolverine

Agreed.
My mind keeps going back to the needles not lifting.

Emet

Hmmm...
I can say for certain that the timing is correct, checked when I fitted the MCCT. And no, it's not 180° out.

As for the carb diaphragms, I inspected them with a light as thoroughly as I could and there was no indications of damage. However, depending on the price I may just order new ones along with new petcock diaphragms too to be safe.

I checked my vacuum lines and there is no indication of any cracks or holes either. Also double checked that everything that's supposed to be capped is, and that everything that's supposed to be linked together is.

I also put on new carb boots today and sadly sheered off a cylinder head bolt after rechecking cam timing. Funds are running low and it's the end of the semester so might have to put the project on pause for a bit so I can pay my rent 😭

Not giving up yet

Emet

PS
Anyone got a part number or source for the petcock diaphragms?

Wolverine

So if you are 100% confident your carbs are good, next step I'd recommend is to crack both valve covers off and reinspect cam timing. I know this isn't what you want to hear but it is needed to eliminate the possibility.

skokievtr

Cylinder head bolt did you mean the valve cover bolt? What cylinder head bolt do you need to play with in order to check the cams?

Did you mean cam journal cap bolt?

The way the valve cover bolts are designed. You really can't overtighten them unless you use a ten foot cheater.

There's also something called a torque wrench.

Emet

Some months of radio static, I have returned to report:

After rechecking timing, rechecking vacuum lines, rechecking everything else mentioned here, AND new petcock diaphragms, I have not solved the issue. Now that its summer and warmer, the bike runs a lot better overall. the 6.5k rpm wall seems to be softer now and the bike will run above 6.5k if I am easing the throttle (although I have not gone higher than 7k). Engine falls on its face when WO above 6.5k rpm. I suppose only things I am missing in regards to this issue would be
1. Balance carbs
2. Compression test
3. Valve clearance test
Other than that maybe jetting?

Also the speedometer, temp gauge, and odometer all stopped working (at the same time) so gotta get that working too.

As for my sheered bolt, I meant the valve cover bolt as "skokievtr" says

Cheers

Bald Eagle

If the bike just dies when you go over 6.5K.....and does not backfire....I believe it is a fuel problem. Sounds like you are just running out of fuel, and when you back off....it then continues to run. The fuel tap has to operate on a vacuum from one of the cylinders...may be check that. There is I believe a manual position on the fuel tap. The other thing to look at is the float levels are just too low. if someone has played with the carbs....??? just some thoughts.
Good luck.

xeris

Yes, it does seem likely that fuel delivery is the problem.
Read through all the posts again and don't see a question regarding where the vac line from below the front carb is attached to the fuel petcock. Wouldn't be the first time this vac line has been put on wrong.
I am not aware of a "manual position" for the petcock.

Emet

Xeris, in my post when I first created the thread I said "have already had the vacuum line into the wrong part of the petcock which I considered my initiation into the SH world" so no worries on that front thank you for replying.

When I replaced fuel petcock diaphragms I didn't take a super close look at the fuel screen so I will probably take another look at that just to be sure. Other than that my buddy has told me to run some kind of carb cleaner solution through the gas tank, which I am planning on doing... also found out my bike seems to be burning oil :'( add into the mix some of the guages stopped working and I am feeling kinda sad LMAO I paid too much for this dang bike to have this many issues. Since I bought this bike and have scowered the forums for possible fixes to this 6.5k rpm problem I have seen so many threads describing a very similar problem with no solution in the end (old dead threads). If I was wealthy I would 100% send this bike out to whoever else to fix it for me but I am just a young college student. Then again, if I was wealthy, I would have bought a KTM 1290 Adventure or a Honda vfr1200x.

Bald Eagle, thank you for your input! My bike DOES backfire, but only on DECEL and quite mildly only here and there (its worse in the colder weather). Doesn't seem very far out of the ordinary in the warmer temps.

After I potentially reinspect the fuel screen, maybe blow out the fuel lines with air, and run a carb cleaning solution through the gas tank, (and yes the vacuum line is where it belongs), I think I would be eliminating a fueling issue as a cause for my problem (since at this point I have checked everything relating to the fueling at least twice or replaced it) . If I can get some money together I would like to pay someone to balance my carbs and check my compression (I don't have any of the specialty tools for that) and perhaps that would be the best next step. Could be bad rings or something causing the burning oil and possibly contributing to the ~6.5k rpm limit fault too. IDK though I am just thinking out loud at this point.

Another thing I am considering is switching the cylinders vacuum lines. If I remember correctly, the vacuum line leading to petcock is currently on the rear cylinder while the front is capped.

After running into that 6.5k rpm wall enough times it does seem it could be just one cylinder cutting out while the other keeps going steadily. It is DEFINITELY not running on one cylinder all the time and runs seemingly perfect (in the warmer weather) from idle to 6.5k rpm. Bike has been super reliable and I have been practicing 1st gear wheelies and trying to shift up while holding the wheelie

I know I have read other posts talking about the "finiky-ness" of the SH so at this point who f'kin knows I might just sell this beast or leave it as is and just accept it

Wolverine

If I were in your predicament, I'd search for a set of spare carbs. If it's absolutely not cam timing related, I'd lean toward fueling. But wait.. there's more. First I'd make sure your r/r is up to snuff and coils.

How much oil is it consuming?

xeris

Certainly a **** off.
As Wolverine suggested, because of the gauges malfunctioning, you should check the r/r. This is a known problem component.
You are right about the vac line to the petcock being below the rear carb, I have one on both, as I have a permanent carb sync setup and forgot the stock configuration.
It's interesting that where you say the power drops off, 6500rpm, is about where the mains really come in, (6000rpm, somebody correct me if this is wrong). Thinking this is a diagnostic clue.
Any idea if the crab jetting has been altered? Did the bike come to you with aftermarket exhaust? The reason for that last question is a lot of people think they have to re-jet for an aftermarket exhaust, which really isn't necessary.
Lower compression, imo, wouldn't cause the issue you're having. Engine would still rev, but be down somewhat on power.
My bike does use a bit more oil when running for long periods (3+hours) at 5000ish rpm. You should be able to determine if oil consumption abnormal by looking a the plugs.
In the end, it's most likely fuel or cam timing. I know you've checked the timing, but.......

Wolverine

I’m stuck on the carbs too because of that rpm, like you state, it’s coming on mains. We need some high res pics of the needles, their positioning on the slide and the main jets themselves. Wish I lived close, I’d be more than willing to have a look-see.

Emet

Well, its a new day... Had a nice layer of bugs splatted on the front fairing so I gave it a wash with my garden hose. Lo and behold, I start the hog up and its even more F'd! Front cylinder now dropping out from idle to about 3k rpms where it picks back up again. The funny thing is that when I first start the bike up, it runs dreamy for about 20 seconds or so then the front cylinder starts dropping out :'( only thing that changed from yesterday, when it was running as it has, to today is WATER. My bike does not like water. FML. Tried running it with the fuel tank lid open to make sure it wasn't an issue with ventilation and no change.

Back to the carbs eh? I was thinking the same thing. As for the jetting, Its got a 48 pilot jet and 175/178 mains (175 front, 178 rear) which I believe is stock? Its got an aftermarket air filter though! Also r/r and coils, yeah that would be worth checking too. Also will probably need to inspect wiring relating to ignition as there are a few places there is some electrical tape so who knows what's lurking underneath.

It would seem that the low RPM fault is a separate problem than the high RPM fault. *sigh*

As for the burning oil situation, it doesnt seem outrageous. I need to throw some more oil in maybe every two weeks. I usually check the oil level frequently and as soon as it gets to the bottom line by the sight glass I top it off. *sigh*

God help me!

Heres a vid of it. Note when the rpms are floating around 1k I am not touching the throttle: https://drive.google.com/file/d/1x5C...usp=drive_link

One more thing I forgot to mention was that I was out and about a few weeks ago, went to gas station, and battery didnt have enough juice to get the starter going fast enough to start the bike. Had some random dude help me bump start it, drove home, put it on a battery tender, and havent had it do that again yet. So theres that too...

xeris

You mentioned an issue with the cap on the high tension wire not fully seating on the plug. Did get that resolved?
Wondering if the carb slides move freely to fully open using a finger.

Levib90

I had the same problem, shim the needles, and not 1 or 2 shims but more like double that figure. That solved my problem. I run k&n air filter, hight mount open pipes, 190 main jets, 47 pilots and needles on the 5th position. Flies like a jet plane. Hope you get everything sorted out, the bike can be a pain in the ***

xeris

Just curious, with the jetting and needles shimmed and positioned as you have, what do the spark plugs and exhaust outlets look like? Seems as though that combination would be very rich.

Emet

Checked my valve clearances yesterday:
front exhaust - .1mm
front intake - .05mm
rear exhaust - .1mm
rear intake - 0.08mm

Carb slides do move freely with my finger and both butterfly valves also open all the way with throttle

xeris

Valve clearances are tight. Should be, according to the service manual: intake .16mm, exhaust .31mm.

Levib90

just a little bit rich, i also don't know how, but it seems to work with my vtr... On the other hand, better a bit rich then to lean...