Thumper Club Forum

Technical => Bike Problems/Questions => Topic started by: kevberlin on December 22, 2023, 04:45:31 PM

Title: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: kevberlin on December 22, 2023, 04:45:31 PM
I’m no mechanic so my local bike man determined that the rattling noise on my bike wasn’t the cam chain ……… it was a badly worn cam follower. Worse was to follow as he was unable to remove the securing dowel without the possibility of causing fatal damage.
Luckily, I’d previous had dealings with an engineering company specialising in British bike restoration.
They looked at the problem, considered various options and have opted to use a process called spark erosion.
David Silver supplied the new dowel and this will, post Xmas, be offered up to determine the depth of the spark erosion process.
All new to me, but I’m hoping for success. This may be of interest to 250rs owners as it is appears to be a known issue.
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: Itsme on December 23, 2023, 07:56:19 AM
I can see why your man said the cam followers are badly worn!

Hope all goes well and you get a good result.

Ian
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: tevie54 on December 23, 2023, 08:39:04 AM
This is a well known problem and one I have done many times, I have a video on YouTube to show how to do it, basically you weld a nut onto the dowel and use a slide hammer to extract the dowels, it's a far simpler method than spark erosion and the method suggested in the manual rarely works, if you need any more info let me know.
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: kevberlin on December 23, 2023, 01:05:24 PM
Thanks fellahs. The one cam follower is incredibly bad but I have sourced a new one.
The welded nut option was also considered, but the engineer chose the erosion tactic.
It should be sorted in the early part of January so I will update on success or failure. Fingers crossed
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: kevberlin on January 05, 2024, 03:07:55 PM
Picked up my rocker cover today with new dowels and cam followers fitted. A sigh of relief. Hoping the bike will be back and running next week.
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: Itsme on January 05, 2024, 09:03:02 PM
That's good news Kev. Hope it goes back together well.

Ian
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: CrazyFrog on January 07, 2024, 07:39:57 PM
Great, look forward to hearing it's back on the road for spring!
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: Moto63 on January 07, 2024, 08:21:05 PM
Yes. Good news indeedy that everything seems to be going well Kev. Look forward to hearing of future progress reports 🤞👍
Cheers, Michael
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: kevberlin on January 11, 2024, 02:34:54 PM
Thanks fellahs. Pleased to report I collected my Cb250rs today. It sounds completely different, with the dreaded top end rattle a thing of the past. Rode home in the grotty weather but with a smile on my face. Great little bike in my humble view. Cheers. 🏍?🏍?🏍?🤟🤟🤟
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: Itsme on January 11, 2024, 04:38:05 PM
Hey that is really good to hear Kev, time to dream of miles to come.

Even weather can't spoil a good ride, I'd rather be on my bike in the rain than in a car in the warm.

Ian
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: Moto63 on January 11, 2024, 05:20:59 PM
Yes great news Kev. Glad to hear all went swimmingly (rode home in the rain, swimmingly 🤦???🧥🚪🚕) 😁 👍
Cheers... name withheld to protect the speedo wearers of this world 🤦???
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: xbally on January 12, 2024, 04:07:37 PM
Thanks for posting this up Kev. Glad you got it sorted.

You'll be interested to know the ignition switch you very kindly donated last year is still going strong. I did have to disturb it today though as I've been having problems with noisy speedo and tacho head drives. I changed the tacho for this reason today and have now worked out the clocks can be changed without removing the ignition switch.

Martin
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: kevberlin on January 13, 2024, 07:18:30 AM
Thanks Martin.
I am pleased all is well at your end.
I’d love to pop over and have a look at your bikes once the warmer weather arrives.

Kev
Title: Re: Cb250rs Rocker cover. Immovable Dowel. For Information.
Post by: xbally on January 13, 2024, 09:39:01 AM
Hi Kev,yes that would be great.Just let me know when you want to come.