GT250 ignition timing setting

GandT · Post by **GandT** » Sat Jan 09, 2021 3:08 pm

Hi
Is the ignition timing setting for a GT 250 L 1974 set at 2.93 mm ? BTDC (seems very advanced to me but I am more used to Yam Rds )
Thanks
K

dollydog · Post by **dollydog** » Sun Jan 10, 2021 2:33 pm

if i remember rightly, the timing for the 250l is 2.88mm or 24 degrees. 250a was slightly retarded 4 degrees or 2.05mm

if you've got one of the dial gauges like i have, set the timing while the engine is out of the frame. mine won't fit with the engine in because of the top frame tubes

cheers, dd.

GandT · Post by **GandT** » Mon Jan 11, 2021 11:59 am

Thanks for reply.
2.88mm is not in any manual I have (although not materially different to 2.93MM to be an issue) -so I will probably go with 2.9 - middle ground.
Do you know if the actual points for each side are the same (backing plate is not, I know) - on mine they are different and that does not seem correct ??

I am using a dial-guage (and with the various rod lengths in the set- I can access the pistons with ram air covers off easily enough)

The Haynes manual refers to value for the M model -which indicates 2.93MM (it also shows 2.05MM for A, B, C models)
I believe from a different thread on this site that mine is an L engine ( 1974) - so is the same setting as an M ?
If M and L are the same I am happy with that, but as you know ignition timing is critical and if it is set wrong poor running or worse can result, especially if too advanced.
Hence my wanting to be 100% sure, but I find the model range referred to in manuals is not comprehensive and data seems to vary a lot.
Thanks for your help.

dollydog · Post by **dollydog** » Mon Jan 11, 2021 1:26 pm

there's a lot of good info on ozebook if you look carefully

try this page: http://www.ozebook.com/compendium/techb ... %201-5.pdf and scroll down to ignition timing, all models

cheers, dd.

GandT · Post by **GandT** » Mon Jan 11, 2021 1:34 pm

Thanks Dollydog
That link shows 2.93Mm - cheers
K

dollydog · Post by **dollydog** » Tue Jan 12, 2021 5:03 am

trouble is in the suzuki bulletins 27-33, under ignition timing it says 2.88mm

still says 24 degrees though. perhaps somebody worked the degrees of advance compared to metric measurement out wrong?

cheers, dd.

daxman · Post by **daxman** » Thu Jan 14, 2021 7:35 am

GandT wrote: ↑Mon Jan 11, 2021 11:59 am
Do you know if the actual points for each side are the same (backing plate is not, I know) - on mine they are different and that does not seem correct ??

I believe they are supposed to be different and IIRC from when I replacved mine one side is easier/cheaper to source than the other!

dollydog · Post by **dollydog** » Thu Jan 14, 2021 12:22 pm

obviously different - one is right handed and one is left handed

i've had all sorts of supposed pairs, where one is higher than the other and after much buggering about i finally got them to work ok. i never use points any more, i use my own version of electronic ignition

cheers, dd.

GandT · Post by **GandT** » Fri Jan 15, 2021 1:09 pm

Thanks everyone for the replies. I have it running sweetly now.
K

daxman · Post by **daxman** » Sat Jan 16, 2021 2:44 am

Good news.. Where in Ireland are you BTW?

GandT · Post by **GandT** » Sat Jan 16, 2021 3:29 pm

Daxman
I am located in Dublin.
Cheers
K

daxman · Post by **daxman** » Mon Jan 18, 2021 3:18 pm

Gotcha - hope to be visiting the area as soon as this pesky virus has packed its bags.

GT250 ignition timing setting

GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting

Re: GT250 ignition timing setting