Author Topic: Motor strip  (Read 5482 times)

Offline tlmark

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Re: Motor strip
« Reply #135 on: 27.05. 2018 11:01 »
Hmm 24C and 84% humidity is not the best weather to jump up and down trying to get a newly rebuilt bike to start.
Especially when it won’t start! All I’m getting is spit back through the carb.
A friend did wonder if the timing might need adjusting due to the slightly higher comp pistons?

Online Greybeard

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Re: Motor strip
« Reply #136 on: 27.05. 2018 11:08 »
A simple schoolboy error is having the plug leads reversed. Even if they are in the original orientation at the mag it's quite easy to swap the firing side over when timing the bike.

Offline tlmark

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Re: Motor strip
« Reply #137 on: 27.05. 2018 14:05 »
Cheers GB once the humidity drops I’ll try that

Online bsa-bill

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Re: Motor strip
« Reply #138 on: 27.05. 2018 14:51 »
Quote
A friend did wonder if the timing might need adjusting due to the slightly higher comp pistons?

Well I found that out, you don't say what compression you have , mine was 9. summit, and it refused to fire, high compression can kill the spark but yours is spitting back so there is a spark.
If nothing else works I'd retard it a bit and see if that helps
All the best - Bill
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Offline tlmark

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Re: Motor strip
« Reply #139 on: 27.05. 2018 20:50 »
Hi, Bill, the new pistons are 8.75:1 GPM ones?

I'll try swapping the leads tomorrow if nothing, then I'll check the timing again.  *dunno2*


Offline tlmark

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Re: Motor strip
« Reply #140 on: 04.08. 2018 13:28 »
Well as the long hot summer of 2018 continues I've not been in the garage until last weekend.
pulled the head off and reset the timing to SRM spec 0.312" or 35deg and she started first kick  *roll*

I've it used a couple of times to go to work this week and she now has just over 100 miles
what sort of miles should I do before starting to use the revs?



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Re: Motor strip
« Reply #141 on: 04.08. 2018 14:13 »
G'day tlmark.
As long as you've used the correct run in procedure change the oil and go for it. Rings should be bed in by now.
Cheers
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Offline Sluggo

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Re: Motor strip
« Reply #142 on: 06.08. 2018 09:32 »
Just my 2 cents but break in mileage varies great due to type of rings, clearances, quality of piston, retorque, timing and valve adjustments done, etc etc,, but I am usually a very busy boy the first 500 miles and often up to 750-1000.
I have found numerous retorques required as the gaskets bed in & compress, valve adjustments need frequent checks and adjustments, as well as staying on top of timing and fuel.  10 pages on this thread and not gonna reread the whole thing, but just a WAG here assuming cast iron rings and assume proper cyl finish (Cross hatching)  But it aint bedded in until it stops burning oil, thats for sure.  So get quick bed in and 100 might be okay, But i have never had that kind of success on anything vintage British.   IMHO....

We can bench race this to death, but facts and figures tell the tale.  Do a wet & Dry compression test and then a leakdown test.  That is the final word.  You will have to factor in compression ration a bit, but should be simple enough to tell.  I can tell by reading plugs and watching the tail pipe.
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Offline tlmark

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Re: Motor strip
« Reply #143 on: 12.08. 2018 15:46 »
So far so good, I put her back o the lift today to go round check things and tighten where needed.