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R90s rough running

Posted: Mon Oct 26, 2015 7:18 am
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

Re: R90s rough running

Posted: Mon Oct 26, 2015 7:32 am
by SteveD
Dells don't have diaphragms do they?

Blocked fuel filters?

Re: R90s rough running

Posted: Mon Oct 26, 2015 11:45 am
by jimmyg
They do but the accelerator pumps are squirting on both carburetors.

jimmyg

Re: R90s rough running

Posted: Mon Oct 26, 2015 12:56 pm
by Bamboo812
Check the timing with a strobe; could be a sticky advance unit.

Re: R90s rough running

Posted: Mon Oct 26, 2015 1:09 pm
by jimmyg
thanks bamboo. going in there to inspect now.

Re: R90s rough running

Posted: Mon Oct 26, 2015 1:51 pm
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

Re: R90s rough running

Posted: Mon Oct 26, 2015 2:42 pm
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.

Re: R90s rough running

Posted: Mon Oct 26, 2015 3:27 pm
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?

Re: R90s rough running

Posted: Mon Oct 26, 2015 4:22 pm
by jimmyg
Absolutely. Every points change I disassemble and lube the advance mech as well as the points block.

Strange.

Re: R90s rough running

Posted: Mon Oct 26, 2015 4:30 pm
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.