low to mid range flat spot

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70sbikes
Posts: 120
Joined: 13 Nov 2014 11:44
Location: Melbourne Australia

Re: low to mid range flat spot

Post by 70sbikes »

What model are they please
VM28's (probably a bit bigger than necessary, but re-jetting isn't that difficult). You also need the "top hat" type plastic/metal insert that goes into the carburetor mouth to allow them to be mounted to the standard Morini rubbers (I bought aluminium ones from NLM, and had to cut off about 10mm so an air passage wasn't blocked). K&N filters aren't cheap either...

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barney 66
Posts: 99
Joined: 29 Jun 2024 06:13
Location: Shropshire

Re: low to mid range flat spot

Post by barney 66 »

Great Thanks for the reply and pictures, I will decide end of the Summer if it’s a keeper or not, actually fancy a 500 Strada, as well
Thanks barney
mad muller
Posts: 199
Joined: 19 Aug 2011 11:29
Location: liverpool, england

Re: low to mid range flat spot

Post by mad muller »

I know you said you have checked the timing, if you have a stobe light ,see if the advance is working when you rev the engine , just a thought as all the carb issues have been covered , you should see the timing marks move away from each other upto 6k then full advance , you prob may have tried this .
barney 66
Posts: 99
Joined: 29 Jun 2024 06:13
Location: Shropshire

Re: low to mid range flat spot

Post by barney 66 »

👍I am going to try it again Tomorrow, was busy yesterday and Today, I did also find that my fuel tap wasn’t opening properly when I came to drain the tank

Thanks barney
barney 66
Posts: 99
Joined: 29 Jun 2024 06:13
Location: Shropshire

Re: low to mid range flat spot

Post by barney 66 »

mad muller wrote: 18 Jun 2025 21:25 I know you said you have checked the timing, if you have a stobe light ,see if the advance is working when you rev the engine , just a thought as all the carb issues have been covered , you should see the timing marks move away from each other upto 6k then full advance , you prob may have tried this .
Sorry never actually answered your question, yes timing spot on and advances fine, also put new plug wire on yesterday and ordered new plug caps
Thanks barney
3potjohn
Posts: 1379
Joined: 02 Jun 2007 13:58
Location: Devon

Re: low to mid range flat spot

Post by 3potjohn »

And make sure to have both taps open. Is one the electric variety? A good flow is very important as us old chaps know.
barney 66
Posts: 99
Joined: 29 Jun 2024 06:13
Location: Shropshire

Re: low to mid range flat spot

Post by barney 66 »

Yes one is the electric,I will hold my hand up and say I have only had the electric tap on while riding, but will do what you have suggested Tomorrow 👍
Thanks barney
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