Rd350lc engine rebuild

[hudtm60]

thanks for the info on the leak kit!

[jon]

Jan 12, 2018 4:24:48 GMT 1 hudtm60 said:

Dusty...how did you get that mirror-like finish on the edge of the head? 
Chris

That’s a billet head, so probably came like that.

On a standard head I simply paint it, then whilst ensuring it’s flat by using 400 grit on float glass on the gasket face, simply flat the two sides off.

You can see the results in my thread in the for sale section.

Jon

[dusty350]

Hi
I'm guessing you mean the Lc head;

20170219_131357_zpsggrwoan7 by David Miller, on Flickr

I got all the old paint off the head first. Then I rubbed down the rib that runs around the head as there were some minor marks in it. Then I ran it over my polishing wheel to get it up to a nice shine. I then masked it so I could paint the head;

20170223_121906_zpsadw8pfwc by David Miller, on Flickr

20170304_164839_zpsbdb5s6i6 by David Miller, on Flickr

You could probably get a good finish with some Solvol and elbow grease, but a buffing wheel makes life easy (and quick)

Dusty

[philmill]

Hi Dusty, so the leak kit, that just checks rings and piston does it? I guess crank seals too?? would you recommend doing it before stripping an engine too? just thinking about this motor I have got, sounds sweet and bores look good through the exhaust ports, I am going to strip for vapour blasting and painting anyway. Can I buy one of the kits from eBay, they seem to have them listed for specific bikes.

[dusty350]

Hi
Just seen your question. The kit as standard will check your combustion chamber, so head and base gaskets, crank seals and inlet track (rubbers and reedblock sealing) You can do it on any engine - running or not as long as all the parts are fitted that need to hold pressure. Putting 6psi into an engine will show any leaks. The coolant system extras that Mark made up are useful for testing that circuit too, as the standard set up obviously doesn't check that. I've not looked closely at the ebay versions to know if they would work straight away. I got my bungs off this forum from someone who made them specifically for Lc/pv's.

Dusty

[philmill]

Thanks for the Info Dusty.

[Gunny]

How did the copper pipe to lock the gears work out ?

[tony1964]

Hi Dusty,

Are those crank cases painted or is that the vapour blasting look??

Tony

[dusty350]

Hi
The copper pipe works a treat Nice and soft compared to the teeth on the gears so no damage to them.
The main crank cases are vapour blasted. The side cases are powdercoated gloss black.

Dusty

[dbgr]

Hi dusty, just had another look at the build, re Allspeeds, did you get the exhaust flanges (the parts that bolt to the cylinders), machined or made elsewhere because the Allspeeds I have slot over the outside diameter of the protruding flanges and show the chrome finish nearly all the way to the exhaust flange

[dusty350]

Hi
Theses are original Allspeeds and the design you have is the newer/better way of doing it. Helps to stops the oily muck that dribbles out and down the pipes. What I have is how they used to do it, so the flange bolts on and the pipe pushes inside it.

Dusty

[dbgr]

Hi dusty, it seems that yours seem to be the better way of doing things, I didn't run mine too long yet still had the black oily dribbles after about 500miles is there any way of stopping it happening? if left on it marks the chrome..

[dbgr]

Hi dusty, it seems that yours seem to be the better way of doing things, I didn't run mine too long yet still had the black oily dribbles after about 500miles is there any way of stopping it happening? if left on it marks the chrome..

[dusty350]

I use clear silicon sealant on the crush washers and fibre gasket, and then on the inside of the flange where the downpipe pushes in. It helps but it seems inevitable that the dribbles will come at some point !! The flexible nature of the Allspeeds - secured by springs - will allow the oil to find it's way out. Part and parcel of owning them I'm afraid

Dusty

[dbgr]

thanks dusty if you cant fix it, im stumped too, I thought I was doing ok but I guess its just got to be lived with

[dusty350]

Hi
I just think it's part and parcel of owning 2 strokes. I'm not sure how leaky the standard pipes are - I've never had them - only expansions so a standard set up may be better. When you consider the pressure of the gasses entering the downpipe it's no surprise oily residue is forced out. I noticed a dribble on mine the other day and that's only ever ticked over on the driveway since I rebuilt it !! The design you have was a rethink over the old style, and I would have thought better. Making sure all your gaskets are good and adding silicon is your best bet but the dribbles will appear at some point I'm afraid !

Dusty

[mouse]

They all do that sir!

I've had LC's with standard pipes, gibsons, allspeeds and Mark Dents and they have all leaked from the flanges. I just think it is down to vibration from the engine, even Yamaha knew there was a problem with vibration as they altered the flanges on the standard pipes.

As Dusty says the best way to seal them is with silicon, sometimes you get lucky and it does completely stop it, other times, not completely but it is always better using some silicon.

Mouse

[badger1]

How did that dear selector/ neutral helper work out now it’s done. Was it worth doing?

[dusty350]

Hi
Ive not ridden it properly yet. Bike is now finished but ive damaged ligaments in my right knee so cant ride it at the mo😣 Once i do i will report back 😉

Dusty

[donkeychomp]

Want a test pilot? (just kidding )

Alex

[badger1]

Feb 17, 2018 22:50:53 GMT 1 donkeychomp said:

Want a test pilot? (just kidding )

Alex

Yeah seeing as your not using it dusty we could all have a go, call it research and testing!!!

[dusty350]

Ah, you guys, that's really kind I couldn't let you do it for free - I'd have to pay you for your time

Dusty

[bezzer]

Feb 18, 2018 9:12:12 GMT 1 dusty350 said:

Ah, you guys, that's really kind I couldn't let you do it for free - I'd have to pay you for your time

Dusty

I’d settle for you rebuilding my engine in the manner of your awesome builds  Dusty 😁 👍🏻 Lol

[badger1]

Dusty where did you get the stainless crankcase bolts you used please? Did they have numbers/letters on the bolt heads or were they plain
Thanks

[dusty350]

Hi
I got the bolts from a localish fastener suppliers. They did have the raised numbers on the heads. I ground them off then polished the heads of the bolts on my polishing wheel.

Dusty

[badger1]

Yeah was going to do the same sort locally or eBay just was wondering if somewhere did a hex set, buy it job done all in one go

[tony1964]

Hi Dusty, did you use 15mm copper pipe for the balance pipe holes in the reed blocks??



Tony

[dusty350]

Hi Tony
Yep, copper pipe, 12mm for the Lc and 15mm for the pv.

Dusty

[oldbritguy]

Hi Dusty, just spent a couple of days working through this thread and what a fantastic piece of work you have pulled together here. Riding British bikes for years, I am no stranger to the full rebuild some of which are worse than others however I had to compliment you on this piece of work. I plan to run the lc this year with a full strip and rebuild next winter and will have the laptop fired up and this thread running all the way through.
Judging by all the positive comments you have received on this thread, I won't be the only one methinks and if the bike turns out half as good as what you have done then there will be a happy bunny at this end.
Cheers
John

[dusty350]

Hi John
That's kind, thank you. I know we all like pics, and as I was stripping the engine anyway I thought it would be useful to document the process. The Haynes manuals are good but some of the black and white pics leave a bit to be desired. They are still a workshop essential though. The thread hopefully shows that anyone with the time and basic tools can strip and rebuild these engines, as they are so simple. And I was happy for guys to add their own thoughts/ideas and tips as there is always more than one way to do things ! It helped me immensely, and hopefully I've built a better engine thanks to the interaction of forum members. The only thing I wished I'd done differently was to add pics of the strip down process, as that is often more testing than the rebuild !! I did a Ypvs engine build thread ages ago - maybe not so detailed, and that had a bit more about strip down. Maybe I will try and resurrect that thread and link it to this one. The Pv engine bottom end is virtually the same anyway so if you can do one, you can do the other !!
Good luck

Regards

Dusty