R90s rough running

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jimmyg
Posts: 133
Joined: Mon Dec 09, 2013 12:04 pm

R90s rough running

Post by jimmyg »

Decided to take my R90s out yesterday for a nice long ride. It started fine but was running rougher than normal. Some spitting and coughing but I attributed that to the cooler weather.

The whole 45 mile ride to my destination, the bike had this underlying feeling that something wasn't right, especially at lower rpm's.

On my return trip, the bike started ok, but just wouldn't warm up. Continuous spitting, coughing, stalling.

I had plenty of fuel but switched to reserve anyway
If I engaged the choke lever, the idle/low speed improved but eventually coughed again
Freeway speeds felt like I was running on reduced power, not quite 1 cylinder, but the bike wouldn't go faster than about 80.

I got home, and started inspecting.

Pulled the plugs, gap was correct and both produced a nice, fat blue spark
Pulled both float bowls, measuring the quantity (each bowl contained about 55ml)
No dirt, no plugged jets, everything clean and normal looking

I did replace the points a few weeks ago so I guess I'll check that area next.

Any thoughts/ideas would be appreciated.

thanks,

jimmyg
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SteveD
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Joined: Tue Aug 03, 2010 3:29 am
Location: Melbourne, Oz.

Re: R90s rough running

Post by SteveD »

Dells don't have diaphragms do they?

Blocked fuel filters?
Cheers, Steve
Victoria, S.E.Oz.


1982 R100RSR100RS supergallery. https://boxerboy81.smugmug.com/R100RS
2006 K1200R.
1994 R1100GS.
jimmyg
Posts: 133
Joined: Mon Dec 09, 2013 12:04 pm

Re: R90s rough running

Post by jimmyg »

They do but the accelerator pumps are squirting on both carburetors.

jimmyg
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Bamboo812
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Re: R90s rough running

Post by Bamboo812 »

Check the timing with a strobe; could be a sticky advance unit.
jimmyg
Posts: 133
Joined: Mon Dec 09, 2013 12:04 pm

Re: R90s rough running

Post by jimmyg »

thanks bamboo. going in there to inspect now.
jimmyg
Posts: 133
Joined: Mon Dec 09, 2013 12:04 pm

Re: R90s rough running

Post by jimmyg »

found it. points gap closed up. Not sure how that could have happened since the adjustment screw was tight but I reset it and I'll have to monitor.

God, I'll kill someone if I find out the points I purchased were made in China!

thanks,

jimmyg
Kurt in S.A.
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Re: R90s rough running

Post by Kurt in S.A. »

jimmyg wrote:God, I'll kill someone if I find out the points I purchased were made in China!
I don't think you can even time it at all with the knock off points...the rubbing block is way too tall.

Kurt in S.A.
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Bamboo812
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Re: R90s rough running

Post by Bamboo812 »

jimmyg wrote:found it. points gap closed up. Not sure how that could have happened since the adjustment screw was tight but I reset it and I'll have to monitor.
Did you lube the felt block?
jimmyg
Posts: 133
Joined: Mon Dec 09, 2013 12:04 pm

Re: R90s rough running

Post by jimmyg »

Absolutely. Every points change I disassemble and lube the advance mech as well as the points block.

Strange.
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Ross
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Location: Central Coast NSW Australia
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Re: R90s rough running

Post by Ross »

jimmyg wrote:They do but the accelerator pumps are squirting on both carburetors.

jimmyg
I have seen them squirt fuel and it goes some distance too.
Me wittle bit of the web........http://rossmz.blogspot.com/
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