The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Tiedie on September 10, 2025, 05:13:00 PM
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Who has the Siebenrock 860 kit installed? And what problems have you encountered ? I have a BMW mechanic lined up for install this winter.
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Hiya, I've had it installed a couple of years now. No issues, just bolt on. Make sure you have the right kit for your year as I believe there are differences after 1980/81.
The only downside is more high frequency vibration. Vastly improved performance more than makes up for that :tekst-toppie:
I had to back off the recommended ignition timing 2 degrees as I was getting pinging on a hot day under midrange load on 97RON 5%. I do have a non-standard Silent Hectik ignition. However, looking at the pitting on the 650 pistons, that had been going on before I got the bike!
Be prepared to replace things not in the kit. No1 being the exhaust retaining rings (the finned ones). If they have not been off very recently, dremel them part way through and cut them in half with a cold chisel. Don't try to undo them unless they move very easily. You may also find your exhaust system may not be as good as you thought. Consider lapping the valves in. Mine were sealing well and didn't need it. If you have any smoke on startup, rattles from the heads or other things that are not in good order, now is the time to fix them. Wear sunscreen.
Do not use silicon sealant anywhere near the long bolts. One of them is the oil feed to the rocker gear.
I think you get pushrod tube seals in the kit. You can silicon those, but I have not and no leaks. Use standard dino oil for a while. It won't bed in on synthetic. It will run very hot and your pipes will blue for the first few runs. Mine took at least 500 miles of taking it easy, and nearer 1000 to be completely happy. Short runs, keep the revs in the middle (3-4000), let it cool, run again. Heat and cooling cycles will bed it in most effectively. YMMV.
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Thanks for the reply, yes I'm aware of the spefic kits, and the insite you give. I plan to have a fello I know whose father and I have been friends/riding buddies many years ago. The best part is Jake is a BMW tech and he has helped his dad build race bikes and installed these kits before. He told me he installed one in town and Dynoed it at 56HP up from 31HP . I plan to heve anything replace that needs to be plus if we can get a asymmetrical camshaft installed too. Hoping to get it done by the New Year.
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Sounds like you should not have any problems :lurker:
31BHP. Hm. I compared my 650 to modern 400. As an 860, a modern 600 (unless its a 13,000RPM missile!) so (+-) somewhere near :beatnik:
I should put (the bike who must not be named here) on the dyno. Mods to the intake (mainly) and exhaust means she pulls much more than standard.
(Yamaha XVS1300)
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I picked up my kit direct from Siebenrock, the other places didn't offer an LS specific kit. Part number was 1100870. Other R65 after 9/80 are 1100860.
The bike lacked a bit at the top end afterwards, I went up 138 -> 145 in main jet size and it pulls cleanly all the way to redline.
The valve clearances tighened up when the kit was bedding in, it's important to use the wider "engine run in period" clearances after installation.
My bike ran oddly hot for the first couple of hundred km. If I was doing it again I'd change oil after 300 - 500km.
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Out of interest, I have the 307 / 308 carbs. 145 main jet as standard. The needle is set one click richer on these also.
https://bingcarburetor.com/uploads/9/8/7/9/98794296/bmw_jetting_chart_cv_carbs.pdf (https://bingcarburetor.com/uploads/9/8/7/9/98794296/bmw_jetting_chart_cv_carbs.pdf)
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I picked up my kit direct from Siebenrock, the other places didn't offer an LS specific kit. Part number was 1100870. Other R65 after 9/80 are 1100860.
The bike lacked a bit at the top end afterwards, I went up 138 -> 145 in main jet size and it pulls cleanly all the way to redline.
The valve clearances tighened up when the kit was bedding in, it's important to use the wider "engine run in period" clearances after installation.
My bike ran oddly hot for the first couple of hundred km. If I was doing it again I'd change oil after 300 - 500km.
I picked up my kit direct from Siebenrock, the other places didn't offer an LS specific kit. Part number was 1100870. Other R65 after 9/80 are 1100860.
The bike lacked a bit at the top end afterwards, I went up 138 -> 145 in main jet size and it pulls cleanly all the way to redline.
The valve clearances tighened up when the kit was bedding in, it's important to use the wider "engine run in period" clearances after installation.
My bike ran oddly hot for the first couple of hundred km. If I was doing it again I'd change oil after 300 - 500km.
Thanks for the info gents, I will definitely keep you comments in mind.
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Well here's the scoop, got the 860 kit and carb rebuild kits and some other stuff I'm getting done. Took to my Tech who's dad is a member of my riding club. Dynoed it and got 20 HP at the wheel. >:( re-build carbs re-Dynoed it and got 32HP at the wheel , much better. He had me order some miscellaneous stuff like carb springs and other stuff for a 42 year old bike maintenance that sat for 20 years. This weekend he will start pulling the motor apart for the install. Should be ready in a week or so. Can't wait
:lurker: :bmw_smiley:
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:lurker: :lurker:
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Update on my adventure.
So far rebuilt carbs, ordered new carb cables.
He was going to re-tap the final drive fill hole that was stripped by the previous owner. While the final drive was out he was going to lube the splines, but saw oil behind the clutch. Yep you guessed it rear main seal leaking. 42 year old clutch and 45k on the odometer. Done! Checking out the gear box and yep still had the plastic roller for the shifter. Upgrade gear selector kit with metal roller,springs and clips on the way. Some things are more than I expected but while we're in there might as well do it right. As they say 1 and done.
This is going to be a new bike.
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:lurker: :lurker: :lurker:
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Happy Good Friday and Easter riders.
A new issue has popped up. I asked my guy to rebuild the carbs. and I thought he had already done so, but he had only replaced the diaphragm but when he started getting into replacing the orings and such he found that someone in the past had attempted to rebuild the carps. but failed miserability! They stripped the throttle butterfly screws, that black spot is JB weld. I know that JB has it's place but not in a carb. Jake said that both screws were loose and just waiting to be sucked into the engine.
Now for the good news:
The final drive is repaired, swing armback with new boot on, the new clutch and new boot installed, the new rear main seal is in, the little plastic roller for the shifter replaced with the new 5 speed gear selector repair kit is in with new metal gear selector cam, springs and new lock rings, new gaskets seals all sealed up and reinstalled, and yes he tickled the splins with lube the rear of the bike is back together. New throttle cables, new neutral position switch which was weeping. Secondary air system delete.
Heads will go on next week and it'll be ready to fire up.
Sure am glad I asked him to go over the whole thing, it truly is going to be a new bike when I get it back.
Riding season is just getting started here in WNC.
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I'm not sure what to do with a stripped butterfly shaft. There is not a lot of meat on them anyhow. Fill with silver solder, drill and tap. Then carefully fit new screws and peen the ends over. Although the heat will probably soften the brass.
Hopefully, you can buy new shafts.
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I'm not sure what to do with a stripped butterfly shaft. There is not a lot of meat on them anyhow. Fill with silver solder, drill and tap. Then carefully fit new screws and peen the ends over. Although the heat will probably soften the brass.
Hopefully, you can buy new shafts.
Definitely done easily obtained what ever needs replacement @ about $30.00 each shaft and $0.60 for each screw. He works at BMW as parts manager.
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:tekst-toppie:
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R65LS Siebenbrock and major maintenance: it was fired up he said it felt strong.Like @Kelvin and @dogshome said it's running lean so he's going to see if he's got some main jets at work. He's thinking a 142 main jet will be right but I told him to get both and see which one is better.
At $15.00 for the 142 and $5.00 for the 145 it's not that big of a deal.
Ran a quick Dyno last night and said 17 more HP.
Top graph blue line is stock r65 and red is now.
Told em I've been jonesing to ride. :laugh:
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:lurker: :lurker: :lurker: :lurker:
:clap:
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My '81 standard R65 had 145 main jets from the factory.
64/32/325, 326 carbs, may need to go a bit larger with the displacment increase .
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My '81 standard R65 had 145 main jets from the factory.
64/32/325, 326 carbs, may need to go a bit larger with the displacment increase .
I'm thinking that 138 were standard for the 84 LS that's why we got both and try them both out to see which works best. Glad he has a Dyno to work with.