The New And Improved Unofficial R65 Forum V2
Technical Discussion => Misc. Technical Discussion => Topic started by: jamestnewsonr65 on April 24, 2017, 09:21:23 AM
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So after a few problems starting my bike (Recent posts) it turned out to be a combination of spark plugs, battery power and needing a general tune up.
The timing was slightly off, but all is working well now and the bike fires up nicely.
I did a compression test to see if this was part of the overall problem and I got results of 55psi on the left and 80psi on the right.
Should I be looking to check the piston rings and tube seals?
I checked this by removing the 3 pin lead under the front cover, removing the spark plugs and then fitting a compression tester to each cylinder whilst cranking the bike for 2/3 times.
From memory the PSI should be over 120psi at least, so this is a little concerning.
Any advice appreciated.
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Did you hold the throttle wide open?
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You need to get at least 10 compression cycles to get a proper compression test .
You can stop when the pressure on the gauge doesn't go any higher .
As wilcom has said the throttle needs to be held full open during the test .
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The timing was slightly off, but all is working well now and the bike fires up nicely.
I did a compression test to see if this was part of the overall problem and I got results of 55psi on the left and 80psi on the right.
I checked this by removing the 3 pin lead under the front cover, removing the spark plugs and then fitting a compression tester to each cylinder whilst cranking the bike for 2/3 times.
From memory the PSI should be over 120psi at least, so this is a little concerning.
Firstly I'd be buying a new compression tester. Whilst an R65 engine might run with 50~60 psi compression, you would need ether to get it started.
Whilst I applaud the thought that went into disconnecting the beancan, that didn't really stop the coils from being charged up - next time simply disconnect the positive lead to the coil - which as an added bonus, does not require the removal of the front cover :-)
In respect to checking over rings etc, my question is "how well known is this bike to you?". If it is an unknown that you have just restored to life then I would have checked valve guide clearance, had a look at valve sealing and, give the relatively low cost, probably thrown new rings (and if an iron bore a de-glazing hone) at it because then I could restart the "counter" to when I next needed to look.
On the other hand, if the bike is known to you and the distance since last top end refresh is around 50,000km (30,000m) then I'd do the top end refresh irregardless of inspected condition. OR, if it is more than 5 or 6 years since the heads were last off irregardless of mileage.
It may be because the wife's original R65 engine was destroyed by dropping a valve (at 60,000km and 9 years since new) or that my own R65 came to me as a result of dropping a valve (at 52,000km and 10 years) but if I take the heads off an airhead these days I replace at least the exhaust valves - they are cheap compared to new head/piston/cylinder and although I have no "proof" I reckon combustion tempos are a bit higher on unleaded fuel.
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Not sure I had the throttle wide open to be honest. I'll try it again and make sure I do.
I've had the bike for 3 years and restored it apart from the engine. It had been regularly serviced and I have every receipt since new. Covered 18000miles and runs fine. No smoke, oil or anything burning/ leaking.
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Here's a pic for the hell of it.
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Unleaded fuel has been mandated here in the US for a bit over 44 years, I have not seen any valve related issues in this time on vehicles here .
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Unleaded fuel has been mandated here in the US for a bit over 44 years, I have not seen any valve related issues in this time on vehicles here .
Bob - 44 years? Which parallel dimension is yours in?
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Unleaded fuel has been mandated here in the US for a bit over 44 years, I have not seen any valve related issues in this time on vehicles here .
Bob - that may be the case in your dimension, but in mine I think you will find that mandatory unleaded fuel didn't commence until the 80/90s.
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Unleaded fuel has been mandated here in the US for a bit over 44 years, I have not seen any valve related issues in this time on vehicles here .
Bob - 44 years? Which parallel dimension is yours in?
bod, sorry for the multiple messages - the forum is going crazy here and i thought my original post went directly to cyber cemetery.