Cam Chain tension

Questions regarding the DR750

Cam Chain tension

Postby ian » Sun Jul 07, 2019 8:09 pm

When I checked adjustment on the balancer chain today I noticed that the tension on the cam chain is not as tight as it should be. Not completely slack but the chain can be deflected at least 3 or 4mm without any tension. The bike has 70000km on it and the balancer chain has stretched to the point that there is only a little bit of adjustment still possible on the tensioner. I'm guessing this is an indication that the cam chain will be similarly worn. Obviously I now plan to replace balancer and cam chain and tensioner spring as soon as I have the funds available. My question though is this. Does the slack on the cam chain indicate that the tensioner is busy failing, or can the cam chain wear to a point that the tensioner is no longer fully able to take up the slack? The tension on the chain is not slack enough that I risk the chain jumping a tooth, but if it is an indication that the tensioner is failing then I would stop riding the bike immediately until the tensioner has been replaced.

Thanks
Ian
ian
Regular
Regular
 
Posts: 74
Joined: Wed Jul 10, 2013 1:48 pm

Re: Cam Chain tension

Postby BigBob » Mon Jul 08, 2019 8:08 am

I`ll make a couple of general points. The tensioner either works or it doesn`t on Bigs. Very few get to an age where the camchain gets slack enough to be replaced.
Camchan tensioners have a habit of the spring breaking at about 100,000 km, and then you get the chain jumping the sprocket and lots of expensive wreckage.
So, if your chain is slack at an indicated 45,000 miles I would suggest that the mileage is significantly higher and someone has fiddled with the clocks at some point in its history.
This is backed up by the fact that your balance chain is shagged as well, when it should be good for a lot more miles yet.
Maybe your bike has just had a hard life and the balance chain has been over tightened.
Either way, you need to replace both chains and the tensioner asap. Possible also both chain guides.
To do this the engine needs to come out of the frame and on to a bench as the head won`t come off while in the frame.
If you are local to me I can give you a hand doing this, If not you will definitely need a manual and lots of patience.
In addition to both chains, both guides, gasket set, tensioner etc you will need the specific Suzuki rotor puller as nothing else will remove the rotor, only wreck it.
I suggest you use here for your parts https://www.megazip.net/zapchasti-dlya- ... k-k-722817 as they will be less than half the price Suzuki GB will sting you for.
Consider yourself lucky that you get to plan ahead without a wrecked engine, when my tensioner failed it took out all the valves. Mind you, it was at 175,000 miles.
When you get round to this fun job don`t be afraid to ask daft questions on here, it`s better than mangled metal.
User avatar
BigBob
Admin
Admin
 
Posts: 3831
Joined: Sat Jan 23, 2010 10:46 pm
Location: ESSEX

Re: Cam Chain tension

Postby ian » Mon Jul 08, 2019 9:46 am

Thanks Bob. I am going to start getting all the parts together to do this job properly. In the mean time I am thinking about just pulling the cam chain out to have a look and measure it. What is the procedure for cam chain replacement on the Big? Doesn't look like the rotor needs to come off so should be straight forward?
ian
Regular
Regular
 
Posts: 74
Joined: Wed Jul 10, 2013 1:48 pm

Re: Cam Chain tension

Postby BigBob » Mon Jul 08, 2019 2:43 pm

I would be more concerned with the tensioner than the chain personally.
You can take the camchain out by removing the cam cover and the alternator cover.
You`ll need to remove the camshaft and relieve the tension on the chain, so you will need several hands.
Use Suzuki3bond when replacing the cam cover, NOT Hylomar or similar shite which will block your oilways.
User avatar
BigBob
Admin
Admin
 
Posts: 3831
Joined: Sat Jan 23, 2010 10:46 pm
Location: ESSEX

Re: Cam Chain tension

Postby ian » Mon Jul 08, 2019 3:04 pm

OK thanks. Tensioner is my priority too. But it costs nothing to take the chain out so I will have a look at doing that while I'm getting all the other parts together. I'll post back here if I find anything interesting.
ian
Regular
Regular
 
Posts: 74
Joined: Wed Jul 10, 2013 1:48 pm


Return to DR750

Who is online

Users browsing this forum: Bing [Bot] and 1 guest

x