Electrical and idle questions

[snydes]

My FZR400 has been running well ever since my final post with its restoration. I will be changing the Pistons and rings this winter as i am burning some oil even after switching to 20W-50 instead of 10W-40. Just wondering if i should do anything to the cylinders during this operation?

Also my bike seems to have started randomly losing charge. I changed the rear tail lights to LED with resistors and such, and they were working okay at the beginning, except they were a bit dim but blinked faster (unsurprisingly) but now they blink very slow and it seems they barely work. The fronts work fantastic still. The other thing is that the bike after riding to work and such multiple times throughout a week the bike eventually loses enough power somehow and wont start and then i have to fully recharge the battery. Not sure if the stator is not working properly or not but when it was running off a charged battery it sat around 12.30V I saw another thread about this stator and was thinking about buying it but no one ever said if this one fit or not: http://www.ebay.com/itm/281283872449?ru ... 26_rdc%3D1

My bike seems to still have a high idle after riding for a while, from 2300-2800 RPMs but if i let the clutch out in gear slowly and let it catch a bit it drops to around 1700-1900. If i turn the idle screw down more i dont think it will idle when it hasnt been ridden as it has troubles starting too; i'll hit the starter button and it will run the starter for about 2-5sec before it starts catching at all which its very slow to start (https://www.youtube.com/watch?v=pqWASKzm12A)

[Evilchicken0]

The battery should be at 13.5v ish after being charged and you should see it at 14.5v with the engine running. When you rev the bike it should sit at 14.5v, if it spikes then it's probably a reg rec failure but this sounds like the battery. Try to find a test gizmo Blue Point MT130 - its easy to use and will tell you if it's the reg rec, battery or alternator ... I think it's battery.

If your fitting new rings then it's best to get the cylinders honed, the rings on their own will be almost as much as a second hand engine, add in the cost of gaskets and skimming the head / barrels (not essential but good practice) and a new cam chain and honestly, find another engine.

[snydes]

The battery should be at 13.5v ish after being charged and you should see it at 14.5v with the engine running. When you rev the bike it should sit at 14.5v, if it spikes then it's probably a reg rec failure but this sounds like the battery. Try to find a test gizmo Blue Point MT130 - its easy to use and will tell you if it's the reg rec, battery or alternator ... I think it's battery.

If your fitting new rings then it's best to get the cylinders honed, the rings on their own will be almost as much as a second hand engine, add in the cost of gaskets and skimming the head / barrels (not essential but good practice) and a new cam chain and honestly, find another engine.

Okay so yeah it sounds like the battery isn't holding its recovery charge but has a surface charge.

The dealer says that they have ring sets and pistons for about $70 each. Gaskets I would either reuse or buy another Athena set. As for honing that is quite easy to get done yet I wasn't sure if the cylinders needed a nikisile coating. Why do I need a new cam chain? Also what is selling the head or barrels?

Sent from my A0001 using Tapatalk

[Evilchicken0]

A set of piston rings would be about £50 ... so $70 sounds right but I doubt that would be for the actual piston itself either way youre at £200 or $280 just for this. The Thundercat uses Nikasil coating on the bores, if you're using a T'Cat engine then it really isn't worth rebuilding. Nikasil is friction reducing coating, its a specialist applied thing which pushes the price up even more. Skimming the head and top of barrels, it's put into a machine that cuts a small amount of metal off the face leaving it dead flat so when you come to put the engine together again you know the head gasket will seal, you'll also get a slight rise in compression but not much.

Skimmed head



Skimmed barrels



Cam chain .... you're already using a different wt oil so maybe you've run this engine low on oil till the light comes on ... ? your going to take the head and barrels off so I'd say it would be better to change the cam chain - you can use a soft link type cut the old one and use it to pull the new one through. I don't think you need to be a member to view this but my engine build starts at page 14 http://www.400greybike.com/forum/viewto ... &start=130

So I reckon you're looking at:
Rings £200
Skimming £100
Gasket set £100
Cam Chain £50
Stuff £50

Rebuilding an engine isn't cheap, do it once and do it right or do it cheap ....

[snydes]

How would I known if I have a thundercat engine?
I originally had run the bike till low oil because I didn't know how much it burned then now when I switched it has seemed to slow down a lot.
For the barrels your referring to the small the actual cylinder (bore/stroke) correct?
I've already rebuilt this engine a few times trying to get it right the first time. So this second time I will be much more thorough. Last time I rebuilt it I didnt change the cam chain I guess it's probably a good idea. I don't think I would ever find another engine online and to trust it is another thing. Rebuilding this is better than risking a random engine. Honing all the cylinders should probably cost around $100?

Sent from my A0001 using Tapatalk

[Evilchicken0]

Honing is probably less - it can be done with a drill and the barrels in a vice but there are proper machines too. It scratches the barrels a bit like a brushed finish to stainless or aluminium - you can specify the angle of hone too, 45 degrees for road 60 degrees for race, it allows the oil to coat the cylinder so the piston rings slip.

A Thundercat is the YZF600 engine before the R6, it's a 4TV code .... look on the engine number.

You might be right about buying a second engine but over here an engine is about 150 for a 1WG (400) or 3HE, a 200 for a 4JH and bit more still for the 4TV

[willandrip]

Good replies from E.C. as per ..

VIDEO : Starter is fine and reasonably rapid.
Put booster cables on and listen to increased speed from 110% battery voltage.

Slow to catch as carburation is incorrect...same reason idle is erratic...weak mixture more than likely.

Don't re-use gaskets on anything but outer casings and cam cover...too much time wasted at failure for top end o/haul.
Same reason cam chain is replaced at head removal....gasket cost is a major factor.(use genuine head and base)

Those cylinders/pistons do not sound rattly or worn ....actually the opposite.
Put a comp gauge on (wet/dry test) to verify.

What mileage and did you inspect valve stem seals ?

Bottom end/crank big end goes long before cylinder damage/wear on these engines when oil is low.

A honing tool is simple,effective and cheap...easily utilised by anyone that can hold a drill steady if you are determined to replace rings and is considered vital for sealure. Also known as a glaze buster.

[snydes]

Good replies from E.C. as per .. [emoji106]

VIDEO : Starter is fine and reasonably rapid.
Put booster cables on and listen to increased speed from 110% battery voltage.

Slow to catch as carburation is incorrect...same reason idle is erratic...weak mixture more than likely.

Don't re-use gaskets on anything but outer casings and cam cover...too much time wasted at failure for top end o/haul.
Same reason cam chain is replaced at head removal....gasket cost is a major factor.(use genuine head and base)

Those cylinders/pistons do not sound rattly or worn ....actually the opposite.
Put a comp gauge on (wet/dry test) to verify.

What mileage and did you inspect valve stem seals ?

Bottom end/crank big end goes long before cylinder damage/wear on these engines when oil is low.

A honing tool is simple,effective and cheap...easily utilised by anyone that can hold a drill steady if you are determined to replace rings and is considered vital for sealure. Also known as a glaze buster.

Carburetors seem to be great as plugs are a very nice brown. I bought the bike around 65000 and changed valve seals and reseated valves then.
Also I know I have a 1WG engine. So it's not a thundercat


Sent from my A0001 using Tapatalk

[snydes]

Honing is probably less - it can be done with a drill and the barrels in a vice but there are proper machines too. It scratches the barrels a bit like a brushed finish to stainless or aluminium - you can specify the angle of hone too, 45 degrees for road 60 degrees for race, it allows the oil to coat the cylinder so the piston rings slip.

A Thundercat is the YZF600 engine before the R6, it's a 4TV code .... look on the engine number.

You might be right about buying a second engine but over here an engine is about 150 for a 1WG (400) or 3HE, a 200 for a 4JH and bit more still for the 4TV

Where could I find an engine from over there? I rarely see any complete ones online.

Sent from my A0001 using Tapatalk

[willandrip]

Correct carburation at idle and on overrun cannot be verified by plug colour.

Plug colour is only accurate at a "chop" with brand spanking new plugs and a hot engine in perfect condition and tune.
It is really a 2T black art but often waffled on about by 4T owners...pretty irrelevant in 99% of cases.

High/rising idle on a 4t once warmed up is a weak mixture....end of.

[Evilchicken0]

Just to sound like a stuck record
Airbox
Dyno set up