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Post by steve99 on Jan 31, 2024 13:34:37 GMT 1
Hi all, I have started to strip my RD350LC down for restoration The inlets have been ground out and it looks like non standard reeds have been fitted? Any ideas? Also does it look like it has been ported? The actual steel sleeve doesn’t look like it has been cut from what you can see into the inlet. But I don’t have a standard to compare. I haven’t had the barrels off yet Thanks Steve  IMG_6418 by Steve D, on Flickr  IMG_6417 by Steve D, on Flickr |
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Post by dusty350 on Jan 31, 2024 13:38:03 GMT 1
Looks like a Pv reedcage and standard steel reeds.
🙂
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Post by steve99 on Jan 31, 2024 13:41:00 GMT 1
They have took a lot of metal out of the inlet throat to get the reed block in
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Post by dusty350 on Jan 31, 2024 13:46:14 GMT 1
Yes, they won't fit otherwise as too wide for an Lc inlet. The holes in the reedcage have been opened out for the mounting bolts too, so they can bolt on to the barrels.
🙂
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Post by beardy on Jan 31, 2024 13:56:37 GMT 1
For comparison.  This is mine and it is ported. |
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Post by steve99 on Jan 31, 2024 13:59:21 GMT 1
So are you saying mine is not ported? I am hoping it is standard. Any idea why the reeds have been changed? Performance?
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Post by midlifecrisisrd on Jan 31, 2024 14:06:13 GMT 1
So are you saying mine is not ported? I am hoping it is standard. Any idea why the reeds have been changed? Performance? Yours is ported as well Steve |
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Post by steve99 on Jan 31, 2024 14:08:25 GMT 1
Is it ported a lot? Will it run ok. I don’t want a race bike. Carbs still 220 mains
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Post by beardy on Jan 31, 2024 14:10:22 GMT 1
Maybe when you get the barrels off, you may find some tuners marks or initials?
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Post by midlifecrisisrd on Jan 31, 2024 14:10:53 GMT 1
A lot depends on exhaust port height
Inlets opened up and ypvs reeds should help it breath so mixture will be affected
To go to all the effort of fitting ypvs reeds I'd guess its not a light tune
Steve
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Post by steve99 on Jan 31, 2024 14:12:39 GMT 1
That is not good news then. I will be looking for some standard barrels then
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Post by midlifecrisisrd on Jan 31, 2024 14:17:53 GMT 1
The steel liner has been cut at the inlet as the sections beside the boost port usually come down into the inlet window quite a bit
Steve
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Post by Robbieben on Jan 31, 2024 14:36:41 GMT 1
I've seen this before on an LC and GT's fitted with reeds rather than piston port, it was origonally a tuners trick with MX bikes in the 70-80's it improves mid and top end fuelling and allegedly aids to cooling on bikes used on track or long periods of WOT. I'd expect to see some similar work on the exhaust port floor and width, If it has been done well it will be a fairly healthy bike power wise.
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Post by reedpete on Jan 31, 2024 15:59:11 GMT 1
Is it ported a lot? Will it run ok. I don’t want a race bike. Carbs still 220 mains Until you get the barrels off and see what else has been changed you won’t know for sure what you’ve got… so get em off! Looking at what’s been done though, it’s not a race engine… and anyway, TBH a well sorted race bike is a mild mannered as can be until you hit the power band… the only short coming for road use being higher piston wear.. however a bodged up DIY ‘tune’ can do more harm than good… |
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Post by dougw on Feb 1, 2024 10:36:01 GMT 1
My first LC that I bought new in 1983 got a Terry Becket "Road Tune" and head re profile after I had it a year.
Better road bike than stock imo , more power all round.
A Stan Stephens "Full Production Race Tune" was also not bad on the road, but as mentioned, probably would wear out a lot faster than stock.
Current 350LC came with barrels "Ported" by an unknown source, uneven transfer port heights, and had a massive mid range flat spot, then took off like a scalded cat.
Richard Slinn , (Trick Tuning on FB) looked at the barrels, paused and sucked his teeth for a bit, and said he would do what he could.
Transformed it, really nice road bike now.
Richard has a fount of knowledge about LC and YPVS tuning.
No relation to me I may add, but I thought my expensively re-lined barrels might have been scrap until he sorted them for me, so very pleased !
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Post by steve99 on Feb 1, 2024 11:50:20 GMT 1
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Post by steve99 on Feb 1, 2024 11:51:56 GMT 1
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Post by Robbieben on Feb 1, 2024 12:16:05 GMT 1
Definately had work to the exhaust and boost ports too, I'd be half inclined to give the barrels a light hone and a set of rings, clean the heads up smoothing out the bit of damage then run it and see assuming the crank is ok. It may be quite nice to ride on the road, its certainly not a hack and hope job by an ill informed fool, looks to be nice tidy work done properly with knowledge.
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Post by Robbieben on Feb 1, 2024 12:19:52 GMT 1
Is there any stamping or engraving on the barrels? some tuners will mark a barrel with initials and a job number etc
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Post by Tobyjugs on Feb 1, 2024 13:02:44 GMT 1
Is it ported a lot? Will it run ok. I don’t want a race bike. Carbs still 220 mains I have an engine which has the same Reed modification and ported. It makes approximately 65 pk. With the same set up using standard exhausts it is very docile and better to use on the motorway. In this state it measured 48 pk Exhaust are very important for the performance of your engine. Speak to TSA, Mutts Nutts or Mick Abbey. They should be able to sort you out. I would be more concerned about the bore size of the cylinders. |
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Post by Tobyjugs on Feb 1, 2024 13:04:48 GMT 1
For comparison. This is mine and it is ported. Lovely work there. Who did it? |
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Post by steve99 on Feb 1, 2024 13:20:08 GMT 1
Is there any stamping or engraving on the barrels? some tuners will mark a barrel with initials and a job number etc There’s no marks that I can see. If there was it would have been a German guy that did it as I have imported the bike into England from Frankfurt |
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Post by steve99 on Feb 1, 2024 13:24:49 GMT 1
Just seen H024 - does that mean anything?
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Post by Robbieben on Feb 1, 2024 13:27:36 GMT 1
Is there any stamping or engraving on the barrels? some tuners will mark a barrel with initials and a job number etc There’s no marks that I can see. If there was it would have been a German guy that did it as I have imported the bike into England from Frankfurt German or possibly Dutch, they have a great 2 stroke scene over there still and well organised racing for various classes of bikes, the pre 70's, 80's & 90's 2 stroke class have a huge following. I've been to Oschesleben a good few times to spectate. Its a shame we don't have similar racing here. |
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Post by Robbieben on Feb 1, 2024 13:43:14 GMT 1
Just seen H024 - does that mean anything? It could possibly be Hoffi, he is a well known German 2 stroke tuner, he also owns a shop specialising in older 2 strokes from the 60's onwards, he races, repairs and restores old bikes. Lovely fella that I've dealt with in the past on visits to Germany. |
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Post by steve63 on Feb 1, 2024 14:14:50 GMT 1
The top of the transfers don't look like they have been touched just judging by your photos. These are the hardest part to do anything with for a home tuner without the right equipment. Bigger reeds, more port-time area on the reeds should make it better all round than standard. The main difference in porting between the 4L0 and YPVS was larger inlets. The difference was they put a vertical bridge in on the YPVS to limit piston rock and improve piston life. The F2/N2 inlet then went bigger again, almost mimicking what Stan the Man was doing on his proddy tunes. I think Yamaha made a mistake with the ignition or pipes on the F2 so their efforts seem to have been wasted. You can still open up a 4L0 inlet but piston life suffers. Raising the exhaust was also done on the 31K YPVS but again the 31K was modified by fitting the YPVS. The problem was not piston rock/life because of the higher exhaust port but the engine becoming peaky. I wouldn't worry about it. Make sure the bores/pistons/rings are good and see how it goes. If it's flat as a fart below 7,000 and then goes like a rocket at 7,100 but is horrible to ride then get someone like Muttsnuts (Dave) to try and sort it as it is. In the mean time have a look for some standard barrels for a reasonable price anyway (or a Unicorn  ). Replica cylinders are now available so all is not lost. |
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Post by dougw on Feb 1, 2024 14:50:43 GMT 1
For a rough (Very) indication of the state of tune measure the distance between the top of the cylinder and the top of the exhaust port. Stock (after first year) was 30mm , 27mm was the height of one well known tuners "Prodie" tune. From cylinder top to top of transfers was 43mm. (These days everybody talks in degrees , back in the old days we used to talk about mm in our ignorance  ) |
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Post by steve99 on Feb 1, 2024 21:06:42 GMT 1
I have managed to find some original barrels totally original.. These will be going up for sale along with the ypvs reeds. Any idea what they are worth?
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Post by midlifecrisisrd on Feb 1, 2024 21:49:09 GMT 1
I have managed to find some original barrels totally original.. These will be going up for sale along with the ypvs reeds. Any idea what they are worth? What bore are they on and what is the exhaust port roof to top of barrel These are the 2 things that will directly affect the price Steve |
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Post by steve99 on Feb 1, 2024 21:57:29 GMT 1
I’ll check tomorrow and let you know
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). Replica cylinders are now available so all is not lost.
)