Author Topic: New to me 75 rd200  (Read 518 times)

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Offline NivagRD

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Re: New to me 75 rd200
« Reply #15 on: April 30, 2021, 04:55:22 PM »
It would be worth taking the exhausts off, at the header pipe to cylinder barrel junction and removing the baffles. Inspect with a small torch. It is possible that a layer of carbon has built up and is causing restriction. Also, whilst the pipes are off, check the exhaust ports for carbon build up too. For ignition timing it is best to use a dial indicator garge set up in an adaptor in the spark plug hole. These small engined two stroke twins like their spark timing spot on.
1973 LS2, 1980 RD200DX, 2019 CB650R.

Offline wisenuts

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Re: New to me 75 rd200
« Reply #16 on: April 30, 2021, 07:55:36 PM »
Thanks I'll check exhaust tonight. Are bh8s-10 plugs ok? That's what came with it. Looks like it wants b8hs.

Thanks again for all the help

Offline wisenuts

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Re: New to me 75 rd200
« Reply #17 on: April 30, 2021, 09:36:29 PM »
Whlep these are good and plugged up

Offline Astute Greaser

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Re: New to me 75 rd200
« Reply #18 on: April 30, 2021, 11:02:08 PM »
Have a read of this previous thread which should show thoughts on wadding.
Note
UK silencers = USA mufflers
UK baffles = USA silencers
Hopefully resolve some confusion while reading  ::)
https://www.aircooledrdclub.com/smf/index.php?topic=58477.msg463494#msg463494
-Mike

Offline Astute Greaser

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Re: New to me 75 rd200
« Reply #19 on: April 30, 2021, 11:09:24 PM »
Thanks I'll check exhaust tonight. Are bh8s-10 plugs ok? That's what came with it. Looks like it wants b8hs.

Thanks again for all the help

The B model had 3/4" long plugs (threaded section) and A model had 1/2" because of different heads. Why Yamaha did this  ??? ???
Because heads can be interchanged it may be worth taking off heads and checking.
Short plug in deep head = poor burn
Long plug in short head can mean damage.
While heads off give crowns of pistons clean to decarbonise.

Offline NivagRD

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Re: New to me 75 rd200
« Reply #20 on: May 01, 2021, 07:47:55 AM »
B-8HS is the correct heat range of spark plug for A and B models.
1973 LS2, 1980 RD200DX, 2019 CB650R.


Online Alistair64

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Re: New to me 75 rd200
« Reply #22 on: May 04, 2021, 04:54:23 PM »
Mike, isn't Gavin correct as both the 200A and B models use B8HS according to the manuals on this site?
1983 Candy red RD200DX Tuned Special
1986 White/red RD350F1 YPVS - owned since 1987...yes, honestly!!

Offline Astute Greaser

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Re: New to me 75 rd200
« Reply #23 on: May 04, 2021, 05:41:29 PM »
I've heard of both size heads probably on this site.
The NGK site above quotes both sizes and mentions the "B" in particular.
99183-0
My USA C 581 is fitted with a non matching USA 397 engine, so I can't verify physically.  However the identical 581 engine for the USA RD200C (round tank with front disc), the supp manual says plugs are NGK B8ES 3/4"
99185-1
Remember the manuals are not gospel, plenty of errors  :o :o
Also Wisenuts is in USA where the round tank 581 C's were sold. Yamaha may well have done different production run of engines for the USA market :-\
Either way he should check.
-Mike

Offline wisenuts

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Re: New to me 75 rd200
« Reply #24 on: May 05, 2021, 12:42:58 AM »
Any recommendations on needle clip position? It's currently 2nd from bottom

Offline Astute Greaser

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Re: New to me 75 rd200
« Reply #25 on: May 05, 2021, 11:06:05 AM »
3rd from top is standard.


Download the manuals for your bike from here. Which will explain tuning. Others are experts on this this but manual is best start.
https://www.aircooledrdclub.com/manuals.html

-Mike

Offline wisenuts

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Re: New to me 75 rd200
« Reply #26 on: May 05, 2021, 03:04:46 PM »
Thanks Mike. I'll swap that tonight. I've adjusted the throttle cables so the slides engage at the same time. Right side carb wasn't even fully open at WOT. I've confirmed it's got stamped 94 jet. I think the previous owner made carb gasket. There was a fair amount over . Cleaned that up so it nice and flush with the reed block. New 10w30 appears to have fixed clutch issue. I think I'm still going to put new friction discs in and the mutol oil recommended here. If anyone wants to sell me an airbox,I'd appreciate it. :)

Offline Astute Greaser

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Re: New to me 75 rd200
« Reply #27 on: May 05, 2021, 04:53:20 PM »
When looking on eBay make sure you get the two (LH & RH) lids as well. Commonly missing.
The CS3 and CS5 boxes are totally different. The lid seals are usually total wasted/perished but stick on foam door insulation works a treat.
Look at this link reply 6 for my solution to the clamps to hold the rubber intakes. The picture is my RD200A.
https://www.aircooledrdclub.com/smf/index.php?topic=62517.msg495803#msg495803

Offline wisenuts

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Re: New to me 75 rd200
« Reply #28 on: Today at 12:33:57 AM »
So the right piston is fouling plugs while the left runs great. Carbs tuned to spec. 3rd clip down, 94 jet same pod air filters.1 1/4 turn out on air screw. Both have new plug boots and b8hs-10 plugs. Thoughts? Attached vid of sound of right side.

Offline wisenuts

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Re: New to me 75 rd200
« Reply #29 on: Today at 12:43:57 AM »
I also had a friend tell me to adjust the oil pump peg to hit the dot. See attached. Is that correct? Adjust the cable adjuster out to line it up.