NC30 dyno 45hp :(

[krisztian_andre]

It's my standard jap spec nc30. I took it to a dynojet shop to get a chart before I
start tinkering with the carbs. It's killing plugs mainly in the rear two cylinders and the exhaust in the back are less hot. Plugs come out wet and black which they say is possible carb float valve failure or burning oil. It burns oil moderately nothing extreme and compression is ok. Jets are standard late japanese spec 115, 118 I think, exhaust, airbox, flap and filter all standard.

What I'm planning on doing is I'll check coil snd HT lead resistance, max ignition voltage, float heights(6.8mm), changing float valves and setting a/f screw to 2 out. Anything else that I should check? My standard exhaust is quite beat up is there any way to check if its blocked?

I wanted to balance the carbs, but the carbtune guys are refusing to sell me one saying that there is too much fraud coming from Thailand so I'll have to use another method.

Goal is to get 55-ish hp and high 20's torque.

[CMSMJ1]

Have you not got the air/fuel ratio graph? That is what you need.

[krisztian_andre]

Have you not got the air/fuel ratio graph? That is what you need.

I know. I asked for it and the dude said "this carb, can not" meaning he can't or does not know how to produce one on a carbureted bike. It was a dynojet machine, aren't they able to measure that by default?

[lizard821000]

lol, he talks shit.

this happened to me, had to ask for another run.

[porndoguk]

All he needs to do is stick an o2 probe down the exhaust.

Speak to kevprojex on here he runs a dynopro machine and he knows his stuff with the V4s

[royster81]

What's the valve clearances like?

You can have it set up all you like but if the valves arent sealing tight due to one or more being tight/loose power will be lost out the open valves.

[krisztian_andre]

What's the valve clearances like?

You can have it set up all you like but if the valves arent sealing tight due to one or more being tight/loose power will be lost out the open valves.

Haha I don't know, mechanics are hilarious here I asked them to do it twice and they said they did it then I checked the valve cover and it was obviously undisturbed. The general philosophy around here seems to be "oooh motobike very old you buy new is good" or "oooh it is rolling no problem very good".

[lizard821000]

stop posting and get to some bars, mama sans for sale.

[Neosophist]

Learn how to do the job yourself.

Bike sounds generally ragged and old, especially if it lives in a country where this is the general attitude.

Perhaps you have worn valves / piston rings / bores.

It shouldn't be burning oil at all.

If you don't mind getting a few inexpesnive tools then get a set of feeler gauges, a basic spanner set and a compression tester with 8mm adapter and check / set the valve clearances and compression test the bike.

If the plugs are wet then as you said then it's either putting in too much fuel or they are oiling up.

Either-way it's a problem that shouldn't be there and is likely to only get worse unless you find the cause and fix it.

Not hard with some diagnosis.

After you've set the valve clearances and compression tested it you'll know if it's worn inside / valve are leaking.

If it all looks good, carbs are likely the only problem. Sounds to me like it's a bit of both.

[krisztian_andre]

Learn how to do the job yourself.

Bike sounds generally ragged and old, especially if it lives in a country where this is the general attitude.

Perhaps you have worn valves / piston rings / bores.

It shouldn't be burning oil at all.

If you don't mind getting a few inexpesnive tools then get a set of feeler gauges, a basic spanner set and a compression tester with 8mm adapter and check / set the valve clearances and compression test the bike.

If the plugs are wet then as you said then it's either putting in too much fuel or they are oiling up.

Either-way it's a problem that shouldn't be there and is likely to only get worse unless you find the cause and fix it.

Not hard with some diagnosis.

After you've set the valve clearances and compression tested it you'll know if it's worn inside / valve are leaking.

If it all looks good, carbs are likely the only problem. Sounds to me like it's a bit of both.

Learning I am that is certain and in spite of all the difficulties I find it entertaining
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