karl pa wrote: ↑Mon Dec 13, 2021 3:29 pm
You can get away without a dial indicator, I have used a caliper already. you just need someway of measuring and setting the piston 2.93 mm before TDC
Sometimes the marks are that close you can use a timing light with the marks, but the smaller bikes are more affected by the timing off a little than the bigger bikes.
Well I have a simple TDC tool incoming which I have needed for a while anyway for cars and bikes and I will recheck/set timing….hope I find it’s off….
Meantime I have been experimenting with jetting and getting it done just in time for warmest part of day test rides before dark….issue basically not changing so hoping timing marks are off is it or it’s some other electrical thing.
So the coils seem to be not easily available…was thinking coils and or condensers or wires/caps could be an issue….is there a go-to set of replacement coils to use for these bikes in your guys experience? If so pls clue me in….thks…
I’ve had good results with aftermarket coils sold by HVCcycle. As with so many things these days, they are not currently listed presumably because they are out of stock.
Some aftermarket coils are listed on eBay. The few that I looked at did not specify the primary resistance & mounting point spacing — I don’t know if any of them are suitable.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
Yellow02Z06 wrote: ↑Mon Dec 20, 2021 7:55 pm
was thinking coils and or condensers or wires/caps could be an issue
Yes those can be an issue. IMO they fail more often then coil.
Earlier you said you could not see both timing marks. Quickly thought maybe spun Key way. If that happens you try many things. So a dial gauge should help prove that one way or the other.
Hi,
Just a couple of suggestions, swap the coils from left to right, that would either confirm the left coil is duff or not and has anyone thought of a blocked exhaust?
Thks all for continuing to follow this and chiming in and good suggestions.
I did get the simple TDC tool and timed it at 2.9mm TDC as suggested. The marks on the flywheel were very close to accurate, its seems they are not TDC but the firing point..
Unfortunately, no improvement on how it’s running. Left cylinder is firing but way colder than right cylinder still…
I decided to rerecheck the timing dynamically too…it was correct but I did notice that there was sparking at point set for right but not at left….
So my latest suspicion is coils, wires, caps or condensers. I have all on order….did order the coils from Rex’s as suggested (not cheap especially due to the shipping, but oh well I am determined to get this thing running as good as it looks).
The idea to switch coils from one cylinder to the other is of course valid, and I may do that (with my custom brackets for battery etc. it’s a bit of a hassle to take the tank on and off) or just put in the new parts…if one coil is bad I would replace both anyway. And in terms of blocked exhaust I have cleaned the baffles and removed the packing from them….
You don't need to take the tank off. Swap the plug leads right to left and vice versa, and swap the leads to the points at the first connectors. The points will then be operating the 'wrong' coil, but the correct plug/cylinder. Try new plugs too. It still looks fuel though.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
Alan H wrote: ↑Fri Dec 24, 2021 2:31 am
You don't need to take the tank off. Swap the plug leads right to left and vice versa, and swap the leads to the points at the first connectors. The points will then be operating the 'wrong' coil, but the correct plug/cylinder. Try new plugs too. It still looks fuel though.
Thks- I’ll look for the first connector…the only thing left to try fuel wise is go way lean….have put in new plugs twice during process
Well I’m finally getting somewhere…swapped coil connections and wires and indeed right cylinder went colder, left hotter…overall bike ran worse this way too but clearly one of the the coils and or wire and or cap is very bad….now I am anxiously awaiting the new parts….it’s funny I have 3 other twins and have swapped sides with components numerous times to ID faults (have swapped around in triple too, but there’s more combinations-but it took me a long time to get there this time….thks for the nudge Alan….and thks for help all….I’ll report back after new parts received and in….Merry Christmas to all who celebrate it…..
If the points are sparking, it's usually condenser, but this also gives a weaker spark.
Weak spark (with plug cap off and ht lead core near earth) is usually either poor coil or lt lead.
Otherwise cap or plug.
Measure the resistance of the plug cap - I always use NO RESISTOR caps for a better spark on points systems.
You do need either resistor plugs OR caps if pei system though.
Think of how stupid the average person is, then realise that half of them are more stupid than that.
Alan H wrote: ↑Sat Dec 25, 2021 12:53 pm
If the points are sparking, it's usually condenser, but this also gives a weaker spark.
Weak spark (with plug cap off and ht lead core near earth) is usually either poor coil or lt lead.
Otherwise cap or plug.
Measure the resistance of the plug cap - I always use NO RESISTOR caps for a better spark on points systems.
You do need either resistor plugs OR caps if pei system though.
Well points were sparking on the better of the 2 sides! Anyway I have new coils (which have the wires preattached at coil side I beleive) new condensers, and new NGK caps on the way…the old caps were literally resting on ram air part of head anyway…not good….I love the good NGK caps, have put them on most of my bikes…what’s a “PEI”system? by the way…
Yellow02Z06 wrote: ↑Sat Dec 25, 2021 6:18 pm
what’s a “PEI”system? by the way…
Pointless Electronic Ignition
The GT500 and many of the TS models, and I believe X7 used the PEI system, which was a magneto system and didn't use battery power for ignition.
Understood re PEI….I have points….I now await parts
Separate but related: how do I post pics? I get a file invalid, or file too big message…have tried a lot of things like changing from HEIC to pdf, reducing size etc….contacted admin, no response, Alan I not you are a moderator, any hints pls, thks
It now appears that pics can't be uploaded, so you'll have to use a picture posting website and link to the pic(s).
It is a 'free' forum, and that's the main drawback.
I haven't been able to contact the admin either, so it appears that I'm 'it'!!!
Think of how stupid the average person is, then realise that half of them are more stupid than that.
Well I was out of garage for 8 weeks - went to California where my sons live, trailers 2 bikes (H1 triple and 85 GPz900R) and brought three back (RZ350 project!) but main goal now that I’m back is to finish GT250 and solve the running issues….
Got my aftermarket coils and nice new NGK plug caps (just love the quality of those) in, had to make a bracket for the coils…question: the coils have thick square bar formed from stacked plates sticking out either end with a hole in them…ie used for mounting….do these need to be grounded well to frame for coils to function? I don’t think so from what I have read but wonder if anyone knows definitavely?
The aftermarket GT-series coils I've purchased are direct replacements & bolt to the stock bracket.
It depends on the design of your aftermarket coils. The GT500 aftermarket coils I bought have an external ground on that mounting bar.
Also, an extra unneeded ground won't hurt anything.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
