Author Topic: Bad Fit Silencer  (Read 1616 times)

Offline adespin

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Bad Fit Silencer
« on: June 24, 2018, 01:34:30 PM »
Has anyone had problems fitting new David Silver 341 exhaust system, I hit a problem fitting these on today, the outer pipe hits the rear brake pedal pivot on the top seam and will not pass it. The pipe is fully home in the exhaust port and lining up with the rear bolt.  As it's Sunday i'm unable to query this with DS.

1971 cb750 K1

Offline JamesH

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Re: Bad Fit Silencer
« Reply #1 on: June 24, 2018, 01:59:02 PM »
Ade I’d suggest removing # 3 pipe, then refit # 4 on it's own and see if you can get the rear footrest hanger about through the pipe and in position. You may need to seeing / flex the pipe to get it under the rear brake pedal, but you should.have a few mm clearance once the home is in/pipe in position. They've a close/tight fit in this area but hopefully you should be fine..

Offline adespin

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Re: Bad Fit Silencer
« Reply #2 on: June 24, 2018, 03:07:05 PM »
Not a hope in hell James, the silencer body is rubbing on the lever boss, on top of that i have now tried to fit 1 and 2 pipes, the rear hanger bolt is a very tight fit but probably could be persuaded with a mallet, but to my horror when i looked at the front view number 3 pipe is a couple of mil' from touching the filter body. I've now packed them up ready for shipment after i speak to David Silver tomorrow, i wonder what their responce will be.
1971 cb750 K1

Offline JamesH

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Bad Fit Silencer
« Reply #3 on: June 24, 2018, 03:15:28 PM »
Don't take this the wrong way Ade, but I have a feeling this is partly due to the way you're attempting to fit these mate. Compared to Honda parts, the tolerance on those is way worse admittedly, but you do have a fair degree of movement to play with. You need to have all 4 crown/clamps in place to play around with angles/pipe position - a very small change in exit angle translates to a massive shift at the rear silencer.

Certainly looking at the angle of pipe #4 from the front you need to get that pipe much tighter to the frame to follow the correct line - I reckon you could get it to clear the pedal but without being there in person it’s difficult to say.

Anyway, sounds like you drawn a line under it which is probably sensible and have a go with a second set. Fingers crossed for you.
« Last Edit: June 24, 2018, 03:17:53 PM by Jamesh_sussex »

Offline adespin

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Re: Bad Fit Silencer
« Reply #4 on: June 24, 2018, 03:51:10 PM »
Judging by the number of restorations you have completed, you have probably bought and fitted several sets of silencers, have you had this kind of problem, by that i mean you had to send them back, if so were there any quibbles.
1971 cb750 K1

Offline JamesH

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Bad Fit Silencer
« Reply #5 on: June 24, 2018, 04:07:32 PM »
The repro HM341’s are way more of a struggle to fit than either genuine Honda pipes or the HM300’s from Yamiya.

Don't expect a simple slide on / perfect fit/alignment (sadly).

In my experience you have to really ’fight’ them into place.

Unfortunately they will be under tension initially, but after a few heat cycles they generally seem to adopt the new position.

Plenty of other forum members have fitted them so would be good to hear other opinions..

Anyone else care to chime in?

Offline Laverda Dave

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Re: Bad Fit Silencer
« Reply #6 on: June 24, 2018, 05:19:28 PM »
Although not DSS 750 pipes, I bought a complete 400/4 system from DSS and it was an absolute pig to fit. The collector was hard pressed against the sump pan and I thought it was never going to fit but eventually and after taking it slowly and with some manipulation it fitted. I expect the 750 system is similar so keep trying.
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Offline Nurse Julie

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Re: Bad Fit Silencer
« Reply #7 on: June 24, 2018, 05:53:37 PM »
We have had serious struggles with DSS repro pipes, defo a 2 person job with plenty of swearing but got there in the end. Strange, because the CMSNL repro pipes are easier to fit but I thought they all came from the same manufacturer. Maybe DSS sells CMSNL's rejects.
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Offline fryerk

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Re: Bad Fit Silencer
« Reply #8 on: June 24, 2018, 08:00:33 PM »
I agree with James they are a bugger to fit but again with a little patience (not my strong poont) and a bit of persuasion and willing they do go on. Make sure they are fully home on the flange at the head as I’ve found that makes a huge difference if one isn’t quite home

Offline philward

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Re: Bad Fit Silencer
« Reply #9 on: June 24, 2018, 08:14:37 PM »
Its a few years since I fitted a set of CSML repos to my K2 - they'e supposed to be from the same source from memory. I remember really struggling to get the rear mounts to line up but they did fit with much struggling and grumpyness
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Offline Green1

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Re: Bad Fit Silencer
« Reply #10 on: June 24, 2018, 10:54:56 PM »
I have DSS 341's on my K1 The same pipe is close to the oil filter as yours and they just clear the front engine mount bolts and just clear the brake peddle.
I have always struggled to get the two right hand pipes on until today when I realised my rear mount had been bent.
Ten minutes with a block of wood and scissor jack soon had the frame straight again and they now go on with ease.
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Offline Trigger

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Re: Bad Fit Silencer
« Reply #11 on: June 25, 2018, 07:50:04 AM »
I have DSS 341's on my K1 The same pipe is close to the oil filter as yours and they just clear the front engine mount bolts and just clear the brake peddle.
I have always struggled to get the two right hand pipes on until today when I realised my rear mount had been bent.
Ten minutes with a block of wood and scissor jack soon had the frame straight again and they now go on with ease.


I have had that before, a bent rear foot peg right mount out by 4mm and the pipes on that side did not want to line up.

Offline adespin

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Re: Bad Fit Silencer
« Reply #12 on: June 25, 2018, 12:30:46 PM »
I spoke to DS today, they are sending Fedex to pick up the pipes tomorrow, they said they will try them on their bike to test, and suggesting that the frame is possibly bent, but if that is the case then surely pipes number 1 and 3 would also not fit, but they go on ok, anyway time will tell, fingers crossed.
1971 cb750 K1

Offline Trigger

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Re: Bad Fit Silencer
« Reply #13 on: June 25, 2018, 01:24:20 PM »
If it  is ok on the left and having problems on the right, may be rear foot peg hanger bent  ;)

Offline Green1

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Re: Bad Fit Silencer
« Reply #14 on: June 25, 2018, 03:05:27 PM »
There's no strength in the rear hanger at all it bent back easy.
I only realised it was bent as I thought I had better change the rear tyre and give the bike a Crick clean for next weekend.

I can now also confirm I have a small amount of rust starting on No1 pipe
Current bikes
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Honda CB750k1 Candy Gold
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Honda CG125
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Kawasaki ZXR400 J

 

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