Oil Leak Investigation and Working Lights on my Honda Superdream (aka Hawk) - Part 25

Continuing in my project to build a Honda CB250N from boxes of bits, I'm trying to understand what's causing my oil leak and connecting up all the lights.
Nats Nackers Yard Channel -
/ nat'snackersyard
Thanks to Rusty Wrecks for his suggestion to try the CB400T Inlet Rubbers
/ mspete1969

[@deandempsey264]

Well done you the finish is well within sight 👍👍👍

[@RyansGarageUK]

Cheers Dean, I would like to hope its getting closer.

[@frankenbikestien5073]

there are slots in the bae of the barrel that links the bolt tunnel to the cam chain tunnel. this is a honda cock up which serves no purpose. to prevent oil leaks, the corresponding head bolts have ptfe sleeves on them which crush against the base of the cylinder to prevent leaks. these sleeve generally leak like a sieve if re-used multiple times, many people wrap ptfe tape over the top to beef them up a bit or alternatively weld/fill the slots with plastic metal/sealant etc to block them off

[@RyansGarageUK]

Hi, I think that you are most likely 100% correct. I only understood this earlier today after much head scratching and reading forums etc. The bolts I removed had no ptfe sleeves on them which I don't understand why not. Anyway I now need to work out how I'm going to prevent this happening again when I reassemble it later this week. Thank you for your comments I appreciate it. Ryan

[@RyansGarageUK]

Hi, I've noticed that I'm seeing additional comments from you appearing and then disappearing when I try to read them, I can only guess you're trying to post something KZbin won't allow, I'm not removing it I promise. Ryan

[@NatsNackersYard]

Another great one mate. Electrics can be mind boggling at times but really satisfying when they go right.

[@RyansGarageUK]

Thanks Nat, it's just a small step forward but better than nowt

[@timparker9235]

more good progress Ryan - nicely done.

[@RyansGarageUK]

Thanks Tim.

[@lewiscoleman8116]

One place you can check for your oil leak is the bolt for the cam chain tensioner as there is a small seal behind it.

[@RyansGarageUK]

Hi Lewis, I'll double check that thanks. Ryan

[@johntray1462]

nice work Ryan

[@RyansGarageUK]

Thank you John.

[@Matt-we7si]

Check that the cylinder head is nice and flat and barrels by putting a straight edge on the surface and shining a light behind to look and see if its not flat. Great progress, hope this comes along with time.

[@RyansGarageUK]

Cheers Matt, I will and that's great advice, although I now think I've found what the problem is and it appears to be something stupid, which for once might not be me being stupid but Honda this time (maybe). Ryan

[@julieslinedancechannel1771]

Hi Ryan - please note comment made by "Roger7" on the Ultimate Honda Superdream Forum (not sure if you are a member) >> Please look at the slots on the cylinder base. This allows oil to the base of the left hand inner front and rear cylinder bolts. You can seal these slots with plastic metal or fit the two special cylinder bolts fitted with rubber seals. This is where your oil leak is coming from.

[@RyansGarageUK]

Hi Phil, thank you for your comment. I'm sure your correct. This was brought to my attention by another subscriber and I've bought a sealant which I've applied this evening ahead of a rebuild planned for tomorrow. Hopefully this will sort it. Ryan

[@colinculverwell325]

Getting there Ryan. Check out vehicle wiring products for Japanese bullet connectors and insulators as well as all the different coloured cables. If I remember rightly the CB 250/400T was basically the same bike as the super dreams but had bulbous styling rather than the later euro style.

[@RyansGarageUK]

Thanks Colin, I'm trying to reuse as much of the original parts as possible, but I'm just about out of usable old connectors, so may well need to order some soon. Ryan

[@rogerwebster1628]

I have recently sealed the slots with plastic metal and used bolts without seals. No leaks ater 700 miles I used J B Weld High Heat epoxy mastic, good for 1000deg C++

[@RyansGarageUK]

Thanks Roger, I am about to do the rebuild, I've bought what I hope will be a good gasket seal in addition to a new gasket. And I'm optimistic it will sort the issue.

[@bolindow176]

You do a tremendous work, great series to follow. I would most certainly have given up on the engine long ago, but it is nice to see you troubleshoot it and gaining grounds :)

[@RyansGarageUK]

Thank you Bo, that's appreciated. Ryan

[@robertadams4415]

An old trick is spray foot powder. That will help you locate the leaks

[@RyansGarageUK]

Hi Robert, thanks but I'm not sure I understand, is it meant to show where the leak is. Does the powder show oil clearly in some way?

[@robertadams4415]

Yes the white powder will turn brown

[@RyansGarageUK]

@@robertadams4415 okay, thank you.

[@alcord2540]

I changed the instrument lamps on my cb250n to led as they were dim in daylight.I had to leave the original indicator lamp because the right and left indicators have opposite polarity,so an led will only work for one direction.

[@RyansGarageUK]

That;s good. I suspect a careful use of diodes should make it possible to also change the indicators if necessary.

[@Free_Ranger_CT110]

The comp tester doesn't always read true & with small engines & a long hose connected to the gauge the worse it will be. The non return valve in the hose may not seal properly. Try comparing with pressure shown when using the short steel tube to the gauge & hold the rubber seal to the plug hole. With piston rings it's a good idea to gap them in the bore using feeler gauge to check. Lots of info out there showing how it's done, also how to measure bore etc. Good luck with the bike.

[@RyansGarageUK]

Hi, thank you for this suggestion. I'm not sure if it's possible for me to remove the long hose or not, I'll check when I've got a chance. I did gap them with a feeler gauge in the bore and they were within spec shown in the manual which was shown in an earlier video. Regards Ryan

[@Free_Ranger_CT110]

@@RyansGarageUK hi, sorry I missed the video of you gapping the rings. I learned the hard way about faulty readings.. Your trick of fixing the wiring plugs removing the pins with a ground down blade was great. I'll use that idea!

[@tomlibero3780]

At this stage, it is good to replace the bulbs with LEDs ...

[@RyansGarageUK]

Hi Tom, yes that's not a bad idea. I may look into that and do it a little later. Thanks. Ryan

[@team-badseeds]

FFS! Stop referring to yourself as 'stupid'! Yes, you've made a few silly mistakes along the way, but that's how we learn. You're clearly mechanically-minded. A lesser man (like myself!) would've dropped a lit match in the fuel tank ages ago.... Mind you, given your luck so far, the bastard thing probably wouldn't ignite! 😂 I've been enjoying this series so far 👍

[@RyansGarageUK]

Cheers Lee, this made me smile. 👍🏻

[@frankenbikestien5073]

been trying to add a link to a superdream forum thread, are links not allowed and deleted?

[@RyansGarageUK]

I honestly don't know but guess not. I've heard others say links didn't work. I'm not blocking anything and thanks for trying.

[@frankenbikestien5073]

@@RyansGarageUK yes i think it's a youtube thing.......look in the factorium under engine sub section cylinders and pistons, cylinder barrel oilways