Oil out of the intake

[nasiraod]

I just finished restoring my XS400, and after I started it, it started spitting out oil mixed with gas through the air filter, Can anyone point me in the right direction on how to fix this issue? The bike runs, just loads of oil comes out
Sorry, forgot to say it's a 1983 Maxim 400 (XS400J)
After doing a bit more research, people are saying piston rings might need to be replaced, would that be a wise move?
Update: Another symptom that is presenting itself is the bike runs very well cold, even doesn't need the choke to start, however, once it warms up, it just dies, and wouldn't start again till it cools down

 

[nasiraod]

Update: I think I might just sell it, and buy a ready to ride bike. I don't know how much it would cost to to make road worthy

 

[16VGTIDave]

Sounds to me like you need to go over the carbs, clean them 3 or more times, and then change the oil and spark plugs. There are many threads here with all the info you need.

If you try selling with the bike not running well, you will be giving it away.

 

[kshansen]

Did this bike run well before the "restore"? It's always a good idea if at all possible before starting a project like this to just do the minimum work needed to get the engine running. Like clean carbs, adjust valves, change oil(even if you just use some cheap off brand stuff) and any ignition work like points on an older bike. Then ride it some if only around the yard or someplace where you can decide if it has all the gears and such enough to get it warmed up and then do a compression test. This way you don't spend hours and piles of money only to find out the last owner beat the Sh*t out of it and never serviced it.

But before throwing in the towel on this one I'd do some basic trouble shooting. Your basic tune-up, make sure you did not over fill the oil, leave something out of a breather if it has one.

I thought I had a major problem on a Sportster, blowing oil all over the side of the engine. Took some good washing and searching and finally found the fins on the rear cylinder were just a touch bigger around than they should be and they would hold push rod tube just slightly to the side and cause seal to leak. Now I know a Maxim doesn't have push rod tubes but idea is some times simple things can cause what looks like a major problem. On the Sportster it only took a little work with a Dremel tool to shave off the offending fins.

 

[nasiraod]

Thank you very much for both your responses
The main reason why I am thinking about throwing in the towel is because I just passed the first exam to get my motorcycle license, and have only about two months to do my final road test, so I was hoping to get it running so I can practice
If I had space, I would buy another one, and keep working on this since this has been an amazing and fun learning experience
I think I did put a bit more oil than I should, but

Sounds to me like you need to go over the carbs, clean them 3 or more times, and then change the oil and spark plugs. There are many threads here with all the info you need.

I didn't know that the carbs could cause the oil to shoot back out through the air intake, I will certainly try to clean them even more, I also wanted to mention that the main jets on the carbs are mismatched, ie one is #130, and the other is #127.5
I will also take a look at the spark plugs to see what shape they are in

Did this bike run well before the "restore"?

Nope, It was sitting for a very long time, the carbs where solid brick from the inside with dirt
Can the valves be adjusted at home?

Update: I think it was oil overflow, as I saw the oil was coming from the oil breather hose that connect to the air filter box, so that's a relief, I guess, since it stopped spitting oil out
Now the only issue left is that it runs really rough when hot, it's so rough that I am not able to start it again when it dies till it cools down

 

[BBS360]

The stock jets on DOHC bikes are different between left and right carbs. Something to do with the airbox shape.

 

[nasiraod]

The stock jets on DOHC bikes are different between left and right carbs. Something to do with the airbox shape.

You are absolutely right, this is from ShopYamaha.com

Now the jets on mine are 130, and 127.5, which is very different from stock, would that cause any of my symptoms, or other issues?

 

[BBS360]

I'm not the greatest with carb tuning yet but I'd think so. You have richer jets than stock.
Rich enough to not need the choke when cold but too rich to run when warm.

I might have missed it... are you running stock filters, air box, and exhaust? If so stock jet sizes will be the way to go.

It's not always easy/cheap up here in canada but try to get genuine Mikuni jets. Members have had issues with unreliable knockoff jets.


On another note, I just did my MSA with ICBC. What's the two month limit? Just your interim license expiry? Road test appointment date?
Apparently it can take more than two months just to book a road test here on the island.

 

[nasiraod]

There's a shop close by that sells K&L Jets, which according to some people are very good, I'll try to stop by there tomorrow see if I can get a couple of Jets, cause that makes total sense, it runs really well cold with no choke, then starts going down hill as it gets warmer. And yes, I am running stock everything, so I should get those jets
My interim license expires in September, I did my knowledge test last year, but didn't get the chance to go to riding school till this year. Regarding the test booking, the school I went to has very close working relation with ICBC and they have slots reserved for their students, they told me whenever I am ready, I can give them a call and usually get a test date within a week or two, they also provide bike, and gear for the test for free the first time, but I wanted to practice first before I take the test. I know, I am cutting it a bit close :/

 

[kshansen]

One way a carb problem can cause engine to be pushing oil is by leaking needle valve letting gas overfill crankcase while it is sitting. Now a vacuum operated petcock "should" not let that happen IF it is working and you did not forget and leave it set to the "prime" position. My 1978 had both problems and way over filled the crankcase.