Author Topic: engine noise (Read 10482 times)

agro69 · « **on:** February 11, 2013, 05:03:36 PM »

G'day again guys am feeling a little disheartened i just purchased a 1995 st100 ex police for a relatively good price. It has done 113000 kms now when i went to look at it it had been out of rego for six months due to the owner having no time to ride it as he was a prison warden and was just to busy. As it was unregistered i could not take it for a ride but had confidence in it being ok. I did however start it and listen to it checked for smoke etc etc and seemed to be fine. BUT!!! today after getting it regoed i took it for a small ride and when i got back i noticed a deep sounding knocking noise which seemed to be comming from the engine.The noise is a lot more noticable from the right hand side of the engine (were oil cap is). I hope it is nothing major but with my experience with engines knocking normally is not a good sign.Im feeling a little lost as to were to go from here any suggestion would be greatly appreciated Regards Paul......

Brock · « **Reply #1 on:** February 11, 2013, 05:27:50 PM »

Interesting problem Paul, I cant really help from over here with that one. I'm sure there is some one closer who will have info for you.

Is the oil level ok. maybe the carbs need ballancing

saaz · « **Reply #2 on:** February 11, 2013, 05:28:45 PM »

Howdy. The ST11 engine can seem to have a knock at idle, usually around the clutch area (dies it seem quieter when the clutch is in?) and yes it seems to come from the right hand front side. Quite often it does not mean anything is wrong, but a good carb synch usually helps. If the bike has been sitting a while might be a good idea to put something like Techron petrol cleaner through it and go for a decent ride before doing the carb synch. The carb idle jets can clog a little if the bike is left sitting around. Sometimes just a decent ride does wonders. Also make sure the idle is at least 1000rpm or a bit higher.

Mine has 183,000kms on it, and it still makes a bit of those noises the same as when I bought the bike at 75,000kms. So it does not mean things are terminal. In fact the bike seemed so quiet after my Suzuki GS1000 with the clutch rattle that I did not notice any noise for months, and then only in the garage when trying to hear it.

alans1100 · « **Reply #3 on:** February 11, 2013, 05:54:23 PM »

I mentioned this noise to a dealer in Adelaide when i went for my fork seal and spring replacment quote.

Bearings in the clutch is one possibilty but it could also be coming from the gearing (chain??) from the crank shaft to the clutch/oil pump

The knocking sound is only there at idle and goes away as soon as I get under way.

saaz · « **Reply #4 on:** February 11, 2013, 06:15:09 PM »

Part of my noise is just the clutch. Another part might be the gear driving one of the cams, as it is not a tight fit onto the camshaft. Sometimes changing the clutch bearings or oil pump chain might reduce the noises, but sometimes there is no change.

Whizz · « **Reply #5 on:** February 11, 2013, 08:16:52 PM »

Clutch thrust bearings can give you quite a level of noise until the clutch is pulled, then it goes away (because the thrust bearings are under load) and this really only happens when you are in neutral at low revs. (written by an Electronics Engineer, so don;t put too much store by it!!

)

agro69 · « **Reply #6 on:** February 11, 2013, 08:48:21 PM »

Thanks all for the info.

gaz · « **Reply #7 on:** February 11, 2013, 11:41:26 PM »

Quote from: agro69 on February 11, 2013, 08:48:21 PM

Thanks all for the info.

thanks

STeveo · « **Reply #8 on:** February 12, 2013, 07:09:55 AM »

Mine had also sat for 11 months before I bought it (94 1100) and it took three tankfulls with carb cleaner before it ran smoothly. I recently had a knocking type of noise coming from the right front of the engine, but thought it was not metal on metal, and decided to check the timing belt tension, found it to be loose and flapping, tightened and noise gone. The belt tensioner can be accessed through the right side maintence cover.With maintence cover removed, belt cover on head removed, top cover over cam pulley removed and two bolts that hold the top of the main belt cover unscrewed and the cover prised apart with a tyre lever. This will allow you to get a ring spanner onto the tensioner bolt to loosen it, allowing the spring to pull the tensioner pulley up tight (put spanner onto cam pulley to pull belt tension back allowing slack for tensioner) and retighten tensioner clamping bolt. Re install all the bits and see if you still have the noise. But I would also advise that if you do not know the maintence history to change all the oils and fluids so that you know they are fresh. Good choice of bike that will do many hundreds of thousand Kilometres if looked after properly, at 113,000Km it is just run in.
Steve.

Streak · « **Reply #9 on:** February 12, 2013, 07:46:03 AM »

I agree with STeveo, if it has been sitting I would change every oil in sight, my 1996 ST1100 was the same, it was a different bike after a full service and check over

agro69 · « **Reply #10 on:** February 12, 2013, 11:56:25 AM »

Thanks again steve and graham i will attack all the fluids and run some carb cleaner.Am looking at putting valvoline 15w40 engine armour oil in it, is there a carb cleaner additive you recomend Regards Paul...... I must admit im feeling a little more positive about the outcome after speaking with you guys thanks again..

STeveo · « **Reply #11 on:** February 12, 2013, 12:14:06 PM »

The Nulon one worked fine for me. After you have run a couple of tank fulls through with the carb cleaner, get your carbs balanced and you may find the engine noise gone. If carbs are not in sync, the cylinders will be fighting each other at idle, maybe causing a bit of backlash noise. Good idea to get them done so you know they are right.

hobs · « **Reply #12 on:** March 08, 2013, 09:54:33 AM »

Am on my third tank full of petrol with carby cleaner additive. My bike sat for 3yrs (2yrs out in weather before I purchased it). Ran initially ok (idleing only) pulled the carby assy. off and cleaned the jets during the rebuild, but got progressively worse when registered and running on the road (did pull the tank and cleaned it out during the rebuild). Have moved with the bike to SA so am in the process of purging with cleaner to hopefully return to normal running. Good to know that getting into my 3rd tank of additive is not unusual. Don't want to pull the carbys off again as a long way from home (Newcastle NSW) and don't have the resources or spares availability here (Whyalla) as I do at home. The bike is running better with this current tank full and may do a 4th if necessary before riding to Port Augusta for some 'professional' help. Didn't really have any unusual noises (but don't really know what normal noises are).

Abe · « **Reply #13 on:** March 08, 2013, 12:59:08 PM »

Hi Hobs,

If you are going to Middleton, I will have a carb sync snail meter there (don't forget to bring it Turtle) and we/you/Saaz etc (workshop) could do a carb sync and see how she runs. When you had the carbie's off, did you check that the floats were correct, pilot jet, main jet etc are original/manufacturers specs, no holes in the diaphragms. Are the insulators/adapters secured to the inlet and the carb's.

I went through a similar process with mine, but mine was running very rich.

Cheers
Dave

saaz · « **Reply #14 on:** March 08, 2013, 06:47:46 PM »

I will pack a long screwdriver then, as it makes the job so much easier. "Normal' noise vary a lot. Mine has some clutch and a bit of can gear noise, others don't. I recently listed to an ST11 with 14K on it, something wrong with it as no noises!

Quote from: Abe on March 08, 2013, 12:59:08 PM

Hi Hobs,

If you are going to Middleton, I will have a carb sync snail meter there (don't forget to bring it Turtle) and we/you/Saaz etc (workshop) could do a carb sync and see how she runs. When you had the carbie's off, did you check that the floats were correct, pilot jet, main jet etc are original/manufacturers specs, no holes in the diaphragms. Are the insulators/adapters secured to the inlet and the carb's.

I went through a similar process with mine, but mine was running very rich.

Cheers
Dave

Abe · « **Reply #15 on:** March 08, 2013, 06:59:15 PM »

Thanks John, yes that dreaded funny screwdriver may be needed, if Hobs wants any assistance (he's going great by himself so far). There may be a little "workshop" time over the weekend, I'm more than happy to assist in anyway.

Cheers
Dave

saaz · « **Reply #16 on:** March 08, 2013, 07:32:26 PM »

Another tip is to put some white paint on the adjustment screws (and the clamps for the carb insulators) as it makes it easier to find them - too late for that tip now.

Turtle · « **Reply #17 on:** March 08, 2013, 11:09:49 PM »

Carb flow meter packed Abe :) all ready for Middleton st1100 servicing day

hobs · « **Reply #18 on:** March 09, 2013, 06:34:27 AM »

WOW!! Middleton, had to look it up on the map. That's a long way from Whyalla. Probably wont be there as don't have the time to get there and back on one weekend. Would love to be there, but time will not be on my side. When is the meeting?

When I pulled the carbys off i cleaned out the jets, checked that the floats and parts were ok and servicable. Didn't do any settings with float levels or other adjustments as at the time didn't have the knowledge or manual. Everything seemed ok and original. The previous owner did not do any preventative maintenance or fix anything that didn't stop the bike. Reason I got it so cheap.

Thanks for your great offer and support, hopefully will catch up on other events soon. Have to do another fix on the bike this weekend, then address the carby issues.

You lot are one bunch of generous guys.

StinkyPete · « **Reply #19 on:** March 09, 2013, 06:43:35 AM »

Hobs, go to http://ozstoc.com/index.php?topic=3063.0 to see the program for the Middleton Rally. It's going to be a great meet.

Marcus · « **Reply #20 on:** March 09, 2013, 08:04:16 AM »

Quote from: agro69 on February 12, 2013, 11:56:25 AM

Thanks again steve and graham i will attack all the fluids and run some carb cleaner.Am looking at putting valvoline 15w40 engine armour oil in it, is there a carb cleaner additive you recomend Regards Paul...... I must admit im feeling a little more positive about the outcome after speaking with you guys thanks again..

What was the outcome of this?

News:

Author Topic: engine noise (Read 10482 times)

Turtle