Classic British SparesKlempf British PartsBaxter CycleBritBike Sponsor SteadfastCyclesSRM EngineeringLucas Classic MotorcycleHepolite PistonsIndustrial tec supply

Upgrade your membership to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Welcome to BritBike Forum!
Britbike forum logo
Member Spotlight
Posts: 163
Joined: September 2008
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Thread Like Summary
Gordon Gray
Total Likes: 2
Original Post (Thread Starter)
#824588 09/23/2020 7:54 PM
by edunham
I have not used my B50 special in a couple of years. It has always been a PITA to start and I have been having various problems with my kickstarting leg, so I thought I would try and sort out the starting issues. The symptoms were what felt like tremendously high compression and the bike simply wouldn't start if the carb was tickled. It might start if it wasn't. Add to that the kickstart didn't want to return on its own. The bike ran great once started though. All of the symptoms seemed worse this year when I drug it out of the storage unit, although it is more likely that it is my kick start leg which has gotten worse.
Anyway, after a number of false starts, that took more time than I care to admit, I think I have solved it. When I took a cold compression test, the compression was 135-140. Right about where it ought to be. I tested the PVL ignition coil and it was a bit weak, so I replaced it with one that tested stronger. But the big issue was that the outer timing cover was binding the kick starter shaft just enough that the kicker wouldn't return and when the frictional force was added to the force of compression, it felt like ridiculously high compression. I loosened the middle screw for the cover and the kick starter shot right back up. I retightened it and it continued to do so. I then loosened all of the screws around the periphery and retightened them, testing the kick starter as I did so. It continued to shoot back up. I then tried to start it, including tickling. The compression, while high (it is 10-1 stock) no longer felt ridiculous and it started from cold in 4-5 kicks. Hallelujah! A little more tweaking and I should be able to get it down to 1 or 2 kicks from cold.
My theory is that my original PVL coil was having a difficult time dealing with the compression and I was probably not spinning the motor fast enough with the extra drag. The timing cover may or may not be original to the engine. The bike is a bitsa. I bought the engine from Gordon Gray a few years back, who got it from someone else. It has replacement cases. I have redone the top end and have been into the primary, but that is about it. The chassis is from a b25 hulk I bought one year at Mid-Ohio. In the future, if a kickstarter is lazy to return, I will try loosening all the timing cover screws and re-tightning first.

Ed from NJ
Liked Replies
#824765 Sep 25th a 12:21 PM
by JubeePrince
I love a quick/easy fix....enjoy!


1 member likes this
Job CycleBritish Cycle SupplyMorries PlaceKlempf British PartsPodtronicVintage MagazineBSA Unit SinglesBritBike SponsorBritish Tools & FastenersBritBike SponsorBritBike Sponsor

© 1996-2021
Powered by UBB.threads™ PHP Forum Software 7.7.5