Author Topic: Missing engine bolts  (Read 91 times)

Ric00ard

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Missing engine bolts
« on: January 24, 2021, 04:06:33 PM »
Hi all. I am a new owner of a Honda SLR650. Giving the bike a thorough check over before putting it back on the road, having purchased it without an MOT, I noticed the nut missing from the rear lower engine mount. ( near the gearbox sprocket ). Being concerned about this I checked the other engine mount nuts & bolts. The rear, top mount nut and bolt were also loose. I also noticed the main front nut was replaced with a nyloc type.( ie not a Honda OEM ).  Is this possibly due to the vibey nature of this single ? Or perhaps is it more likely the engine has been out and not put back with the nuts properly torqued ? ( the bike has 27k miles on the clock - believed genuine ) Any experiences of this would be most useful. Thank you.

themoudie

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Re: Missing engine bolts
« Reply #1 on: January 25, 2021, 02:01:47 AM »
Aye Ric00ard,

Welcome to the madhouse! ;)

I have an SRX600 monoshock that has steel lock nuts holding the frame tubes to main frame. After re-assembling the bike with nyloc nuts and torqueing them to the recommended torque 25 ft/lb, I think, I managed to loose 3 bolts and nuts along with the respective washers in under 500 miles!  :-[

I replaced all the nuts, bolts and washers, with the OME high tensile fixings, applied copper slip, torqued to the factory settings and have since done ~10,000 miles without loss!

My Ducati 450 also did a similar party trick and I have reverted to high tensile fixings and steel lock-nuts, with a dab of Loctite nut lock. So far, during running in ~500 miles, no losses.

Go over the whole machine with a torque wrench, including the Allen cap head set screws and see what shifts. Check that the washers where required are in place, clean the threads with brake cleaner if anything is a bit iffy and re-assemble with a touch of Loctite nut lock and torque to the factory torque. If you can obtain a factory workshop manual, do, as it will have a full table of all the values for the machine. Unfortunately, I do not have a manual for the SLR650, but others on here may do.

Good health, Bill

iansoady

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Re: Missing engine bolts
« Reply #2 on: January 25, 2021, 10:29:14 AM »
I have a pdf copy which is a bit illegible but you're welcome to it. If you want it send me a pm and I'll let you have details.
Ian.
1952 Norton ES2
1955 Francis Barnett Cruiser

mthee

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Re: Missing engine bolts
« Reply #3 on: January 25, 2021, 12:04:27 PM »
Thanks for this, Bill. Although I never reuse nylocs, I think the all-steel, reusable versions in select places might be worth the investment, given your feedback here. Do you have a supplier at a canny price, then?😁
Fear of the unknown does not mean the unknown needs to be feared

Ric00ard

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Re: Missing engine bolts
« Reply #4 on: January 25, 2021, 07:18:38 PM »
Thank you Bill for your advice, it is much appreciated and thank you Iansoady for the offer of the pdf.
However I fortunately received a workshop manual with the bike, so I shall get “torquing” as advised !

themoudie

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Re: Missing engine bolts
« Reply #5 on: January 25, 2021, 08:25:01 PM »
Aye mthee.

For these types of nuts I always use INOX Fasteners. The man has done his own restorations and knows what is required. As a one man band he may not be the cheapest, but you will get personal attention to your order and an intertest in your project.

Here is the link to the INOX page for 'Aerotight' nuts that are all steel.

Link:Hexagon Aerotight© All Metal Self Locking Nut

Alternatively you could fit either square or rectangular section spring washers or crinkle washers that are less likely to damage metal finishes. I wouldn't advise either toothed washer types.

Link: Various washers

Good health, Bill
« Last Edit: January 25, 2021, 08:58:02 PM by themoudie »