Rattle help!

[Calkat88]

Hey Katgurus, I'm new to the group because I've just picked up an '05 Kat 750 that came to me with a rattle in the engine. I know it's hard to diagnose without hearing it but I wanted to know if the Kats had any kind of flawed component that would cause a rattle in the engine? Some achillies heel like thing known to the Kats?

I thought it was a valve and took it to my mechanic who adjusted them and said that wasn't the cause of the rattle but that he wasn't worried because the rattle slap doesn't increase with the RPM's and gets quieter as you rev it. His thought was that finding the noise wasn't worth the tear down because he didn't think it was harmful. I've ridden it a few times since and it performs fine, but the rattle bothers me. It hasn't gotten any louder with more riding either. The bike has 26k miles

Has this ever happened to anyone else?
Thanks

[arsenic]

It's the cam chain tensioner spring is my guess. Replace it and you should be fine. It's a known issue with any similar cam chain tensioner. Especially one that's 10 years old.

[Calkat88]

And that isn't something my mechanic should have seen while having the top cover off?

Is that an easy fix or a nightmare to get to and deal with?

Any way to test for it, or is it just a look and see kind of thing.

Thanks so much.

[arsenic]

Honestly, your "mechanic" probably did know, he just didn't care. You own a Katana, it's a cheap and easy job. It's not a big money making job. It's nothing you have to have the cover off for, nor is it anything you can see. Once you've heard it two or three times, you know it. There is less slack in the cam chain the faster it's rotating. That's why I suspect it's the cam chain tensioner spring. It gets quieter the faster it moves. If tension were consistent, that wouldn't happen. There really isn't anyway to "test" for it, like I said, you just know it when you hear it. It's like a $4 dollar part and a 15 minute job if it's your first time. This is not head mechanic type work.

[Calkat88]

Solid. I'm after it then. I'll look it up in the online manual. I'll buy the part from Ron Ayres unless this site supports another seller.

Thanks. Help like this saves time, money, and most of all, sanity.

[Calkat88]

Hey, I had a shop install the cam chain tensioner spring...it's a long story but they didn't charge me to do it. BUT the rattle persists. They were not a Suzuki shop and they did say it seemed like the rattle was coming from that area... But it sounds the same after the new spring as it did before.

Two shops in trying to solve the rattle haven't had a solution but did do work to rule out valve adjustment and cam tensioner spring.

New ideas? I know without hearing it, I'm asking a lot but...anything come to mind. It's an 05 with 26 k miles

[arsenic]

You're adding more questions then you're answering. You had a "shop" install the spring. That's really a very simple job. How do you know if they set the tension correctly? You don't. The only thing you've ruled out is that those two "shops" didn't fix it.

[Calkat88]

Right. Sorry to bother you.

[IanDMacDonald]

Me personally, I've never had issues with ACCT's before (with the exception of installing one incorrectly in my youth and bending 16 valves). However, on my track bike '07 GSXR750, I converted to a manual cam chain tensioner. It's more reliable using the titanium bolt and nuts I sourced, rather than hoping a ratcheting mechanism never fails.

It's funny, because we went from CCT's to ACCT's, and the trend is back to CCT's.

Hey, I had a shop install the cam chain tensioner spring...it's a long story but they didn't charge me to do it. BUT the rattle persists. They were not a Suzuki shop and they did say it seemed like the rattle was coming from that area... But it sounds the same after the new spring as it did before.

Two shops in trying to solve the rattle haven't had a solution but did do work to rule out valve adjustment and cam tensioner spring.

New ideas? I know without hearing it, I'm asking a lot but...anything come to mind. It's an 05 with 26 k miles

I'm thinking it could be the tensioner guide arms?

[arsenic]

Right. Sorry to bother you.

Sorry if the truth offends you man. You asked for help. You did not prove that the spring was not the problem. You proved a shop that didn't charge you anything said that the spring wasn't the problem. Let me know when you're period is over and we can get back to fixing your issue. Or just sell it now and save yourself the trouble of having other shops not fix your problems.

[Calkat88]

did you mean " I'm not yet convinvced the tensioner spring isn't the problem, even though a shop put it in, it could have been done improperly, which happens, and will make you look elsewhere when it really is this issue." Then you'd probably give me instruction on just taking it out myself and checking it for proper tension, and since the gaskets are only a day old i might get away with reusing them. Is that what you meant? It's some times hard to hear the care and interest in helping people in this forum for helping people through the 1980's era insults.

Also the reason I had a shop do the simple repair was because they owed me for something else and asked if this repair could square our deal, so I used it as a win win, thinking a dedicated MC shop would do a proper installation and it would be fixed or I could rule it out as a culprit because, well, a MC mechanic did the install. Bad logic in your mind? I only introduced this issue to them on your advice, I didn't ask them to chase the rattle down.

I'd appreciate if we got back to helping me fix my bike.

[IanDMacDonald]

Well, here's the deal sir: there is nothing "simple" about an ACCT repair of you're not familiar with the procedure, or are not mechanically-savvy. Reason(s) I say this are because the ACCT keeps tension on the cam chain, which keeps the chain on the cam sprockets, which in-turn keeps the bike in-time. Any sort of error in this procedure could cause an expensive repair, i.e. (bent valves, piston damage, etc.)

These are interference engines, so the common issue with messing with the cam chain is slack, usually on the back side of the motor. If the chain is not pulled tight around the intake/exhaust sprocket, the chain could skip a tooth and throw the timing off.

So, in-response to your question, Arsenic answered it based-off common issues with these motors. ACCT are a known weak point. If he told you how to fix it, would you be capable? Or would you attempt it, bend all the valves and blame him for the advice?

My suggestion would be to get a service manual, whether Clymer/Haynes/Suzuki, and study it. Then, study it again. Then, after you're done, study it one more time. THEN, follow the procedure for ACCT adjustment.

My other suggestion would be to remove the valve cover while doing this to make sure the chain does not have slack.

Good luck!

[92xjunker]

There are tricks to getting the chain taught, that most newer MC mechanics wouldn't know. Like backing the engine off to put the slack on the adjuster side. When was the last valve adjustment done?

[Calkat88]

Well I read the procedure in the manual that's downloadable here, and Arsenic said it wasn't too difficult, but I thought having a shop do it would insure that the procedure was done right. Is the common feeling that you are better to do these things yourself than have a shop do them?

Should I just take it apart myself and follow the reseating instruction in the manual before I can say this isn't the problem?

What I got from Arsenics post was that by having a shop do it, I created more questions because that doesn't mean it was done right, since they didn't charge me.

The valves were adjusted within the last two weeks

[92xjunker]

Just so you are aware. The Kat motor can be a little ticky. It's just inherent to the motor. Air cooled bike are a dinosaur these days so, most mechanics don't want to or know how to properly service them, unless it an older mechanic. Yes, you should learn to service you own bike. I have never had a mechanic service my bike. I learn to do what needs to be done. This site will be a god send for any support you need but, we won't fix it for you...