Ride Ends Badly SR500 engine fail!

[@derekp2674]

Thanks for this video. I had a T reg one back in the day. It would cruise all day at 70mph and return 70mpg. These days we'd call that an ecobike.

[@cousinjack2841]

Many years ago when I was riding an XS1100, I went to yet another bike rally in South Africa with a load of mates. One of our guys had an accident and ended up in hospital, so a load of us jumped on our bikes to go and see him. I borrowed a mates bike as it was my turn to drive the van on this trip, (yes we were well organised, spit roast and everything), this bike was an SR 500. On the way back to camp I gave it some wellie and when the rest of the group got back, they said they couldn't keep up with me, the smallest bike in the group was an 850. It was at night and all on back roads, and I still remember how impressed I was with the SR. Great fun...apart from the mate in hospital part of course, he ended up losing his foot. Nice video; thanks.

[@barnsleybikervideodiary7694]

Had one back in 1979 , loved it. Sold it to get married! Then 3 XT500’s. I’d sell them then regret it hence this one. This one’s a keeper 😉

[@uodalrich5]

I had the same issue with my sr500. The spark plug loosened after some days of riding since a while and you could move it then in the spark plug drilling hole. To avoid an issue like you had I decided to use an inlay/heli coil to repair it (in a Yamaha shop). It exactly survived one day. Wasted time and money. With a big popping sound my Iridium spark plug disappeared into the fields during my test ride and was never found again. So I organized a new head (costs around 200€/$) which my shop installed for free because of the inlay/heli coil fail. Now it runs fine again. To use srew glue is no good idea.. Screw glue like Loctite 270 describes that you can loosen glued parts by heating them to 250-300°C (450-550°F), so using it in a very hot part of the motor is not recommended.

[@nickguy831]

Sounds like a bag of spanner’s! But at least it didn’t blow just as you say needs a new head.

[@barnsleybikervideodiary7694]

Sounds very much like, if not sweater than the other 4 Yamaha singles I’ve owned, the spark plug deciding to leave the party brought the fun to a temporary halt. Replacement head sat waiting to go on.

[@Phiyedough]

I had a Honda XBR500, wish I still had it as it was a lot of fun.

[@Banditmanuk]

O dear. Hope you get it sorted. Nice to bump into you at the Stafford Classic

[@barnsleybikervideodiary7694]

Just got home, thanks. Will check your channel later.

[@bananabrooks3836]

Spark plug thread can easily be repaired by a competent motor engineer. I'd rather do this than buy and use a head with an unknown history.

[@markgallagher2386]

The thread has already been repaired and it’s the repair that failed! The bare head has arrived and looks mint - having been vapour blasted. I’ll be checking it carefully, maybe do a mild gas flow and have new valve guides in my spares collection if needed. The unknown is condition of existing cam, bearings and followers which I plan to swap over. The engine had a reborn, high comp piston and new valves just before I bought it!

[@bananabrooks3836]

I meant 'repaired' as in made good, rather than 'it works if you don't rev the bike' 😁

[@markgallagher2386]

@@bananabrooks3836 I’m going to have it inspected but suspect a repair won’t be easy as insert has a lot of slack in it. If it can be done I’ll do it and keep as a back up maybe.

[@AndrewCaton-q6s]

Love the trip out as I am a Yorkshire lad from Hoyland. And remember the roads very well, so nice to see. .maybe you should take a trip to Hermit Hill at Wortley. I was born at the nursing home at Wortley. I hope all goes well with the cylinder head swap 👍🏻😎

[@staryjanek]

Oooft ! I had that happen on one of the cyls on my K75, wonder why the power dropped and my left leg was being electrocuted :) all part of the fun innit

[@chriscampbell3688]

Looks like an easy fix. When you put a replacement spark plug insert in you always must use Loctite, but not the blue one. Blue is for normal bolts/threads but red Loctite 272 is for any thread that will get hot on an engine. Didn't see any signs of any Loctite on your spark plug insert. That's probably why it failed as it unscrewed itself, hence you were able to screw it back in and get home.

[@barnsleybikervideodiary7694]

Once it’s off we’ll asses if threads are ok so we can try a replacement insert. If done properly a timesert shouldn’t need any thread lock to stay in place. Will know better once the heads off .

[@martinowl]

A good ride round the area. Bike sounded as though it was running well prior to the plug incident.

[@barnsleybikervideodiary7694]

Was running sweet which is why I wound it on 🥴

[@chriserskine585]

Do not miss kick-starts, my xr600 was a mare to start, and if you stalled at the lights and engine was warm then it was interesting to say the least😂

[@barnsleybikervideodiary7694]

Luckily I have a choice of ride so the SR (and my 1978 Bonniville) are for special occasions only 😉

[@hodaka1000]

There are better thread repair inserts than Heli-Coil Look for the ones that are like a solid insert instead of the wire coil types Some have a rim around one end of the insert and the tools that come with them include one that cuts a recess for this rim You might find these solid inserts are a little larger than a Heli-Coil and may be suitable to repair your exsisting head

[@barnsleybikervideodiary7694]

@@hodaka1000 we think the repair was done with a Wurth Time sert, but done badly!

[@bigronvfr750]

Sounds like the small end has gone

[@barnsleybikervideodiary7694]

Sounds very much like, if not sweater than the other 4 Yamaha singles I’ve owned, the spark plug deciding to leave the party brought the fun to a temporary halt. Replacement head sat waiting to go on.

[@bigronvfr750]

@@barnsleybikervideodiary7694 thanks for the reply, could you have bored out and cut a thread for a larger spark plug?

[@hodaka1000]

​@@bigronvfr750 Yeah nah

[@bigronvfr750]

Is that not a xt 500 ?

[@barnsleybikervideodiary7694]

No it’s an SR but has an XT alloy tank fitted.

[@bigronvfr750]

@@barnsleybikervideodiary7694 ar ok yes it was the tank that I reconsidered 👍