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Ljivasiv82
Posted on Sunday, September 04, 2016 - 04:05 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

So about 1 out of 10 times when I try to start the bike, there is a terrible detonation or heavy clunk, what I assume is inside the engine. It sounds terrible and I'd guess not normal. It's almost a combination of metal on metal hit and then grinding. Me calling it a knock/detonation is pure speculation & ignorance of the proper terms.

Now I know detonation is usually a combination of high pressure and heat, where the mixture ignites prematurely. Since this is a cold start, could this be ruled out?

I've watched a few engine seized videos & people trying to start one that has been seized. Frighteningly it sounds a bit like that, metal on metal grinding. I checked my oil (Amsoil) & it's full. Could it be something to do with the oil draining out of the engine & an issue during startup. Then being fine once the oil pump gets the oil going?

Could it be a timing issue? This only happens 1 out of 10 starts or less, and never an issue while the engine is running & it idles beautifully.

Please forgive me if I sound ignorant on my description, I'm no mechanic. Maybe someone has experience. I'll try to video it but it happens so infrequently.
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Hughlysses
Posted on Sunday, September 04, 2016 - 04:45 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I think it's very unlikely it's an engine problem. If it were, your engine would have self-destructed by now. My guess is it's a problem with the starter. I'd forest make sure it's not loose. If it's not, you may have to remove it and have it checked out.
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Ljivasiv82
Posted on Sunday, September 04, 2016 - 06:20 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thanks for the info Hughlysses, I think you're absolutely right. I needed to understand how a started works, so I found this video (https://www.youtube.com/watch?v=8WD5Q_PF3pM#t=103. 284255). Not sure if that's a car or motorcycle starter but I assume the function is pretty identical.

From my preliminary research, it would seem that the start pinnion wheel does not disengage (retract) from the fly wheel once engine starts. Then the engine stalls as it attempts to crank the starter. So could the grinding noise be the starter being cranked by the engine right before the stall? or is the engine strong enough in idle to keep cranking the starter if the pinnion remains in contact with the fly wheel?

Of course the grinding might just be the pinnion wheel and fly wheel teeth mashing due to misalignment or worn teeth. Though I think if this were the case, this would be an issue on EVERY start. I think the problem is with the pinnion wheel either not engaging or disengaging, hence why it happens once in a while.

Also, would a grounding problem creating an issue with the starter acting up?

Thanks
Lyu

(Message edited by LJIvasiv82 on September 04, 2016)

(Message edited by LJIvasiv82 on September 04, 2016)

(Message edited by LJIvasiv82 on September 04, 2016)
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Hughlysses
Posted on Sunday, September 04, 2016 - 08:31 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

A bad ground would keep the starter from working, but wouldn't cause this issue.
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Griffmeister
Posted on Sunday, September 04, 2016 - 11:24 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

It could also be a combination of some of the things you mentioned, call it a perfect storm if you will. Some starter issues will creep up slowly, I had my pinion go bad but it started as an occasional thing. When I heard your bike start before, I noticed that it had the typical compression stall on occasion. You were talking about getting a multimeter, this would be a good problem to try one on. First be sure the battery connections are tight, then measure voltage at the battery while you start the engine. If you see a big voltage drop one of those times when you come up on compression, say to below 8 volts, that might indicate that your battery is not strong enough. This is where the perfect combination comes in. Suppose the engine almost started, came around a little faster than cranking speed putting some slack on the starter, then hit the second compression stroke? Could make a big clunk. At any rate, one out of ten times with the engine running good the rest of the time should rule out internal problems and be more ancillary in nature. If you do make a video with sound that might be helpful.
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Ljivasiv82
Posted on Monday, September 05, 2016 - 12:03 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Griff or others, can you pinpoint all the ground locations on our Ulys?

So far I've read of one (or two?) near the battery, one across the "rear motor mount heim joint" and one to bottom of triple clamp. Any others or am I wrong on ones I listed?

I do believe this has something to do with a high compression position, hence why it happening once in a while. Almost everything I read is pointing to poor grounding. Many threads describe fixing hesitant starts by doing an extra ground from Neg battery to engine/starter. It might be a slight issue on my bike & usually isn't noticeable but only becomes observable when the engine is stopped in a high compression piston position?

I'll order a meter but tomorrow will try to clean as many grounds as I can, as well as the battery connections. Let me know if any info on the Grounding locations I described is incorrect.

(Message edited by LJIvasiv82 on September 05, 2016)
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Teeps
Posted on Monday, September 05, 2016 - 11:49 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Does this happen when the engine is hot or cold?

Try setting the engine, as below, before starting the engine, especially when it's cold.
With ignition switch off:
Shift to 1st gear.
With clutch engaged move the bike backward (it won't move far) until it stops.
Shift to neutral.
Turn the ignition switch to run, then press the starter button.


(Message edited by teeps on September 06, 2016)
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Ljivasiv82
Posted on Tuesday, September 06, 2016 - 12:04 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

It's infrequent so hard to be 100% sure but it has happened after riding the bike and it was off for 10 or so minutes. So the engine should still be hot & our hypothesis of the high compression state sounds plausible.

I'm confused about your suggestion. Why pop it into first gear and move it with clutch engaged? This would do nothing to release the high compression. Maybe "clutch engaged" means not having the clutch pulled in?

Lyu
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Ducbsa
Posted on Tuesday, September 06, 2016 - 05:26 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Maybe "clutch engaged" means not having the clutch pulled in?

Correct, this is a technique that big single racers (Norton Manx, etc.) use to give the flywheels the longest time possible to spin before hitting the first compression stroke. Helps for bump starts and dodgy electric starts.
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Natexlh1000
Posted on Tuesday, September 06, 2016 - 10:27 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

There seems to have been a batch of crappy starters in the 2008 bikes.
Mine never cranked fast even when new.
It got gradually weaker and then the sprag clutch finally didn't want to play.
I replaced it with a chinese knock off and it cranks over fine now.
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Mxnyc
Posted on Friday, September 09, 2016 - 01:28 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Mine has started funny for some time but, it does not seem to be getting worse so I've ignored it thus far. The noise is a terrible noise, I'll agree though.
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Froggy
Posted on Friday, September 09, 2016 - 02:27 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

My 08 also sometimes will make the grinding noise when doing a hot start like after just stopping for gas, never had an issue cold.

Since the bike still starts fine, I'm not worried about it, if it becomes worse or more frequent I'll look into getting the starter replaced next time I have the primary cover off.

Neither of my 06s have done it.
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Ljivasiv82
Posted on Friday, September 09, 2016 - 02:37 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I wonder how identical the noise is. Is it a loud grinding one? I mean it's loud/nasty enough that I my face screeches.
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Froggy
Posted on Friday, September 09, 2016 - 09:00 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Indeed it is
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Ljivasiv82
Posted on Friday, September 09, 2016 - 10:12 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Seem a moot point asking you this as you're obviously know most of these bikes issues but did you ever redo the 3 ground points on the bike?

My research tells me that poor grounding might give the starter some issues.
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Froggy
Posted on Friday, September 09, 2016 - 11:20 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Actually no I haven't, my 08 is pretty close to stock, I've never disturbed the grounds. I never considered that as a possibility, but I don't think that is the culprit though. I've always just chalked it up to a bad batch of starters on the 08s, just like there was a bad batch of fuel pumps on 09s and a bad batch of cranks on 07s.

It certainly is worth investigating the grounds, can't hurt at least.
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Ljivasiv82
Posted on Saturday, September 10, 2016 - 02:08 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I'm trying to go over them this weekend or at least within a week, as well as test the battery, etc.

I'll let you know if I see any improvement once I redo them.
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Ljivasiv82
Posted on Sunday, September 18, 2016 - 01:01 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Ok I finally got around to redoing all the grounds. Interesting the nasty grinding noise has been MIA for weeks now. Nothing has changed with the starter, it still starts pretty much the same. I don't think it is bad though, 80% of the time it goes in 1 crank.

I did notice the engine didn't sputter as much on acceleration from idle. Maybe it's just in my head, I'll keep an eye on it.
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