Yamitriple
Member
Okay guys I have no idea what happened here, just put the first 100 miles on of the year with my 97 sx 700 and it ran decent. Could tell it was rich in the mid, as it had a small bog at around 1/4 to 1/2 throttle. Not a big deal it was running good for the most part. Stoppedthe sled for a little bit, changed my clutch wrap from 60 to 50 (I have power inc pipes still tuning) and was gonna test. Warmed it up and took off gave it the beans and noticed a heavy vibration after 7000 on up to 8100. Didn’t feel right so I went back to the 60 wrap but the vibration stayed! And now the mid range seemed to loose a ton of power and I’m now fouling my pto side plug. Need help figuring this out! Everything was fine till I changed my wrap and tested it. Now it seems everything’s gone to hell! Thank you for any suggestions in advance
Closely look at belt.
Yamitriple
Member
Belt is brand new. No chunks out of it or anything
Yamitriple
Member
Even if belt was messed up that wouldn’t explain why it’s all of a sudden running bad would it? Maybe the vibration but not the bogginess and fouled plugs right?
you have multiple problems here ...need to address one then the others...first off I would wrap the secondary to 70. What plugs are you running ? Those sleds have a tendancie to foul with the stock plugs, try running br9yas.vibrations are usally caused by a bad bearing , either in drive shaft or secondary -jack shaft. Im not far from you if you need help let me know !
Yamitriple
Member
Just did drive bearings, and I run br9es, it’s just strange the way it happened, I think I may have shifted my crank out of index being a piped 97 and all. That’s all I can think of at this point. It’s just hard to believe since I just had crank out and replaced seals and top end. Less than 250 miles on it. I wasn’t cranking crazy rpms either, never passed 8400-8500. I’m stumped lol I am going to check crank index this weekend. Do you work on these?
Yamitriple
Member
Also on a side not I just had my secondary and primary rebuilt by Schmidt bros this summer. Took chain case cover off and bearings are fine also. Skid isn’t missing wheels and track isn’t missing studs or inner drive lugs. Last thing I can think is crank. Did a small test with my clutch as a degree wheel and seemed really close. Obviously that isn’t a sure fire way of knowing but I figured if it was waaay out I’d notice
I seriously doubt your crank is outa phase! I have a 97 with over 20000 miles on er ...running slp pipes, never a crank problem. i used to run the br9es plugs and always fouled out the pto side, switched to br9eya's and never fouled a plug since! also had problems with the plug caps .. they go bad, i know you have a new belt on er . but you need to try another . it dont take much to ruin em and make the sled vibrate like you say. and it sounds like maybe your jetting is off a bit for those pipes. what do you have for that?
Yamitriple
Member
Im jetted 145 mains needles in stock positions 45 pilots with2 turns out on fuel screw. It says on pipe guide to run 143.8 pto but that seemed light for pipes so I bumped up 1 size. I’m sure my needles could be dropped a spot as it wouldn’t run right in the mid and I would foul out if I held her at 1/2 too long. Also seemed to have a slight idle hang after I’d pull on it. I’d say maybe 800-1000 rpms high. Idle set to about 15-1700
Yamitriple
Member
Clutching I’m running 89L weights with 4.5 g rivers and a 46/41 multi helix set to 60 wrap. Stock springs stock rollers. Had good back shift but was about 200-300 rpm higher than target(7950-8200)
it takes less then you think stress wise to move a non welded crankshaft. Easy way to check it is remove the sparkplugs, bring number 1 cylinder to tdc, use a phillips head screw driver thru hole to find tdc, turning the crank by hand via the clutch. Then go down and mark the rim of your primary clutch with a sharpie marker, then move onto cylinder 2, then cylinder 3, marking your primary in the same spot from frame each time. I just use 12 o clock for simplicity. When done just use a cloth tape and should be the same distance, every 120 degrees between your marks, if not.... crank has moved and will need to be pulled, reindexed and then welded so it stays true. I have had the red head engine turn a lot and some just a tad and will make them run horrible, sometimes they backfire,vibrate, etc. it all depends on how far they move. Its not hard to check it!
Yamitriple
Member
I did exactly as you said and it was tough to tell. If she did move it wasn’t alot maybe 5-10 degrees. I know the 97’s where more prone to this when piped than other years aswell. Getting it checked this weekend with a proper degree wheel and I’ll make sure to get back and let you all know the results
Yamitriple
Member
After being retrued and welded how well can I trust it?? Should I not even bother or will I likely be okay? Sled has 5100 km and some change
the amount it moves just determines how bad it runs....lol. just a little bit makes a big differance in timing at peak rpm, so the more it moves the worse it runs and vibrates, they will backfire and pop all kinds of things happen when the piston isnt in time with the port openings! Once its trued and welded it will be 100 percent tough and reliable, you wont spin it again for sure. Yamaha should have welded all the cranks on triples, but didn't do so till 2000 and newer, they had service bulletins on the 98-99 srx engines for exact problem you have , redheads didn't seem to show up till they had some time on them, or blew a belt at high speed, etc, lots of different things can tweak one. You are certainly not the first and wont be the last.
theres a guy on here who does good crank work, his user is sxr1000.
Yamitriple
Member
Thank you for the insight viper. Do you know how reasonable he is? Was gonna send it to northern crankshaft and they told be 200 for a ball park figure on rephase true and weld
Yamitriple
Member
How do I search individuals on here lol
Yamitriple
Member
Also on a side not I have a 2000 sxr 700 also, was that crank factory welded??
sxr1000 = Lyle
Lives here in Minot ND, same place I live.
You can go to advanced search and type his user name in, then send him a PM
Lives here in Minot ND, same place I live.
You can go to advanced search and type his user name in, then send him a PM
Yamitriple
Member
So update on the issue, took sled to my mechanic and had phase check, it was dead nuts. So I have to keep looking, but at least it ain’t worst case!