Tdm 850twin engine slapping or banging

[maff tdm850 twin]

Hi there sorry if I have posted this in the wrong section please direct me to were to posy if I have thanks iv got a tdm 850 twin 1991 I think! I was riding it back from were I bought it and it rides like a dream no problems what so ever anyway I pulled into fuel station to refuel went to get on the bike it wouldn't start unless I pulled throttle right back anyway once it did start I gave it a good few hard revs and it was fine I pulled off no problem joined the motorway  and has I powered on there was a loud funny noise coming from the engine so i pulled over checked oil best I could and had to carry on riding to get home but it fine until about 3000rpm then this banging or slapping noise kicks in and loud and vibrates the whole bike and now it won't rev past like 5 but on tick over there's no noise until u puy the engine under strain please help I thought maybe crank is there any easy way of checking th crank or do anyone know what it could be thanks matthew 

[Fender1515]

As always, it could be as a result of a number of potential issues, but sounds like fuelling or timing issue. From your description of circumstances I would be surprised if it was timing.

My starting points would be: 

1: How low was the petrol when you filled up, it could have pulled crud from the bottom of the tank through, clogging fuel filters and restricting flow

2: Are you 100% sure you put the right fuel in, this sounds remarkably like a problem a  pal had when he  part filled up with diesel,  luckily only put 5 litres into a 3/4 full tank, eventually ran it through, evidence is lot of white smoke from exhaust

3: Has the bike got a service record, when and what was done

4: Could be a failed coil pack, if you run the engine and test for temperature from the exhaust headers, if one is cold then that cylinder has an issue,.

 Other folks on the forum who know these engines better than I do will chip in to help.   

Good luck with the fix

[Tinkicker]

Concur with fender.  As the problem started after the petrol station fill up. It is logical to start with fuel issues.

[maff tdm850 twin]

6 hours ago, Fender1515 said:

As always, it could be as a result of a number of potential issues, but sounds like fuelling or timing issue. From your description of circumstances I would be surprised if it was timing.

My starting points would be: 

1: How low was the petrol when you filled up, it could have pulled crud from the bottom of the tank through, clogging fuel filters and restricting flow

2: Are you 100% sure you put the right fuel in, this sounds remarkably like a problem a  pal had when he  part filled up with diesel,  luckily only put 5 litres into a 3/4 full tank, eventually ran it through, evidence is lot of white smoke from exhaust

3: Has the bike got a service record, when and what was done

4: Could be a failed coil pack, if you run the engine and test for temperature from the exhaust headers, if one is cold then that cylinder has an issue,.

 Other folks on the forum who know these engines better than I do will chip in to help.   

Good luck with the fix

It was really low it was spluttering so nearly run out to be honest so I'll start with fuel I'll report back later thanks guys for ur help really appreciate it 

[maff tdm850 twin]

6 hours ago, Fender1515 said:

As always, it could be as a result of a number of potential issues, but sounds like fuelling or timing issue. From your description of circumstances I would be surprised if it was timing.

My starting points would be: 

1: How low was the petrol when you filled up, it could have pulled crud from the bottom of the tank through, clogging fuel filters and restricting flow

2: Are you 100% sure you put the right fuel in, this sounds remarkably like a problem a  pal had when he  part filled up with diesel,  luckily only put 5 litres into a 3/4 full tank, eventually ran it through, evidence is lot of white smoke from exhaust

3: Has the bike got a service record, when and what was done

4: Could be a failed coil pack, if you run the engine and test for temperature from the exhaust headers, if one is cold then that cylinder has an issue,.

 Other folks on the forum who know these engines better than I do will chip in to help.   

Good luck with the fix

I forgot to mention yeah put right fuel in iv just check receipt lol 

[maff tdm850 twin]

Hi all iv taken the carbs off and yeah there was a load of shit in the bottom give it all a good clean put it back together started it left it tick over for a little bit then wen It was still exactly the same so I thought I'd give a good reving. See if it clears its got a lot worse won't Evan idle now iv taken a little video see if that would help thanks guys but any advice would be much appreciated it won't let me upload video 

[Hairsy]

16 minutes ago, maff tdm850 twin said:

Hi all iv taken the carbs off and yeah there was a load of shit in the bottom give it all a good clean put it back together started it left it tick over for a little bit then wen It was still exactly the same so I thought I'd give a good reving. See if it clears its got a lot worse won't Evan idle now iv taken a little video see if that would help thanks guys but any advice would be much appreciated it won't let me upload video 

 

Easiest thing is to upload to YouTube and then post a link.

[Simon Davey]

Thinking something like the timing chain, but I don't know if it even had one

[maff tdm850 twin]

Here's the link to video iv tried timing chain tensioner, cleaned all cards now it Evan worse I reckon bottom end do anyone know is there bearings each end the crank could it be one them or bottom end bearings 

?

https://youtu.be/Z45eNEJv20g?feature=shared

[Fender1515]

Are you absolutely 100% sure you have got ALL the jets clear, and have you checked the fuel filters ?

 

[maff tdm850 twin]

2 hours ago, Fender1515 said:

Are you absolutely 100% sure you have got ALL the jets clear, and have you checked the fuel filters ?

 

I think so what if jets are shited up it can make the whole engine bang and glang and a big vibration throughout the bike like the bottom end is hanging out iv had cars with bottom end go and it sounds very similar is there a easy way to find out if it is bottom end cause it really sounds like bottom end to have u listend to the video? If you think thar a blocked jet could do this I will strip the carbs again but my gut is telling me it's bottom end! Although when I took bottom of carbs of today the were full of shit like rust bits and that I do know last week i cleaned them so they should be! Is there anyway to bypass fuel filter just to try it co I put the pipe from tank onto the carbs and try that? Thanks for all ur in put guys I really appreciate it

[Simon Davey]

Very difficult to tell. 

It could be "dieseling", which is where fuel isn't being burned so it's making a sound like one of the pistons slaps and rattles (but it actually isn't) . 

I had carb issues for six months until I had the idle jets replaced. 

 Ignoring the rattling, it does sound like it's not firing cleanly. Have you checked for a spark on both cylinders? 

Also, I wouldn't bypass the fuel filter, you'll just allow more crap into the carb's. 

If you found rusty looking junk in the carb's, the first thing is to properly empty and rinse the tank, then once you have fresh fuel you can clean the carb's and remove and clean the jets. 

Definitely worth checking for a decent spark on both plugs. 

Once you actually have it running, yes, the engine could be buggered, so hard to tell. 

[maff tdm850 twin]

4 hours ago, Simon Davey said:

Very difficult to tell. 

It could be "dieseling", which is where fuel isn't being burned so it's making a sound like one of the pistons slaps and rattles (but it actually isn't) . 

I had carb issues for six months until I had the idle jets replaced. 

 Ignoring the rattling, it does sound like it's not firing cleanly. Have you checked for a spark on both cylinders? 

Also, I wouldn't bypass the fuel filter, you'll just allow more crap into the carb's. 

If you found rusty looking junk in the carb's, the first thing is to properly empty and rinse the tank, then once you have fresh fuel you can clean the carb's and remove and clean the jets. 

Definitely worth checking for a decent spark on both plugs. 

Once you actually have it running, yes, the engine could be buggered, so hard to tell. 

Thanks mate do you or does anyone else know is there a way of checking crank and  bearings without actually having to strip the whole engine down thanks 

[Simon Davey]

3 hours ago, maff tdm850 twin said:

Thanks mate do you or does anyone else know is there a way of checking crank and  bearings without actually having to strip the whole engine down thanks 

 

I'm no mechanic, I just have very basic knowledge. You could turn off the fuel, remove the spark plugs. You'll have to to do that to check for a spark, but this will mean there's no actual firing, and no compression. It should be fairly quiet. If not, then it'll be mechanical. 

[Old-codger]

Was this a private sale or from a shop, if the latter take it back and tell them its not fit for purpose. If private it gets tricky.

If it was running perfect before the fill up everything points to either duff fuel or washing all the crap into the carbs when filling up. Are you positive that there is no derv in the tank, Drain the tank completely and clean all the filters and carbs. Have you drained any oil off to see if there is any metal particles in it. When it is running it does sound very clanky if that's a word but diesel can do that.  

[bonio]

If you cleaned the carbs and later found dirt in them, then it's probably coming from sludge in the tank. Perhaps the sludge got stirred up from the bottom of the tank when you filled up. I'd say drain the tank, clean it out. Check and clean the fuel filter too.

Edited Monday at 07:59 by bonio

[maff tdm850 twin]

10 hours ago, Old-codger said:

Was this a private sale or from a shop, if the latter take it back and tell them its not fit for purpose. If private it gets tricky.

If it was running perfect before the fill up everything points to either duff fuel or washing all the crap into the carbs when filling up. Are you positive that there is no derv in the tank, Drain the tank completely and clean all the filters and carbs. Have you drained any oil off to see if there is any metal particles in it. When it is running it does sound very clanky if that's a word but diesel can do that.  

It was private sale I'll give all these ideas s a go tomorrow and report back thanks guys 

[Hairsy]

I know you've said you've already checked it but that does sound like an extreme cam chain tensioner issue.

 

Check this out, which the comments say was a tensioner issue.

 

[RideWithStyles]

Without looking at the vid, it should be FING  IMMACULATE throughout and all parts and mint fit for use throughout, it not your opening yourself for fails. 

Id go with what the others say first.
the other part is does the noise come on at a certain rpm or gear? Does the noise happen to the timing of the engine and speeds or slows down with the engine under load? Stuff like that?

maybe an output shaft bearing worn out? Hell even a crush drive or a kinked chain/side plate can make that noise as it’s going around the small sprocket….

the only proper way to see if the bottom end has failed is to strip it. The quicker but yet fallible way is to drop the oil and inspect, take off the oil filter and cut it up to see if glitter or bits are in it.

Edited Tuesday at 11:19 by RideWithStyles