Hi all,
Recently I bought an engine (03 f4i, unknown mileage) for the second time after the first one didn't work out. I bought it unseen online all the way from Georgia but made sure it had a return policy (30 days, covering shipping if there is something wrong with actual engine) It was guaranteed to run or my money back but there was no mention of much else. I finally received it yesterday and brought it home
Upon a general visual inspection I noticed some things that concerns me
1) Heavy carbon buildup caked on all exhaust valves as well as (it seems) top of pistons
2) Some rust in the intake valves
3) There was also a bolt with a hole in the head like for a safety wire, but just one so I'm not sure how concerning that should be

In addition, I tried hand cranking it very gently (did not want to force things if it was stuck), it did not budge so I poured some oil down the spark plug holes and let it sit for now. Tomorrow I'm going to try hand cranking again and if that works maybe do a basic leakdown test

Carbon buildup seen through spark plugs holes (before I squirted oil in there):



Rust on intake valves
I couldn't take very good pictures, below was the worst of it
Most of them also had a spot or ring of rust around the stem



I didn't get pics of the exhaust valves but they were pretty caked on with carbon.




I do NOT want to rebuild it (would rather rebuild my original engine then), nor take off the head as that might affect my ability to return it

My question is how bad is the rust, do you think it's just surface rust or more serious? Do you think it's cleanable without taking it apart? Combined with the heavy carbon deposit, is the engine worth keeping or even trying out? Should I save myself the pain of hooking it up and just return it? Or should I at least try to run it first, might as well?

Also any tips before I try to run it? (If i can't get it to hand crank at all I'm not even gonna try, gonna send it straight back)

I'm just frustrated because this is like the second engine I've tried and if this one doesn't run I sure don't feel like playing the lottery with a third one. It sucks because in my maybe naive dreams, I just drop in a new used engine, it fires up right away and I ride off into the sunset

Thanks all

 

That head has to be rebuilt, no way you can run with all that rust.

 

send it back
the carbon build up is no big deal. but it seems that engine was stored in a damp environment without the ports being blocked off.
even if you were to rebuild the head and clean the rust off the valves, they would be completely pitted.

 

I agree with ^. Why buy someone else's problems. An engine swap SHOULD be a simple as you describe. Buy elsewhere.

 

Fuuuuuuuuuuuuuuu
You guys basically confirmed my fears. I think I was so hopeful I just didn't want to believe.
Thanks all for your replies, really appreciate. Gona contact the seller today. Dammit

 

There's more going on there than just the rust on the valves. Those ports look like there's blowback or oil or something going on.

They should be clean. And they are not...

 

Hi, thanks for the reply. So I just googled blow back, so it's when gases go backwards from cylinder to intake? How could you tell from just looking at the port? (Don't take me wrong not doubting you... I want to learn! one of the reasons I joined this forum ^^)

 

Like the rest. The Carbon means nothing toss in a bottle of dry gas and itll burn right off..
Problem is those valve stems. That one in particular is not AT ALL Surface rust Its corrosive rust. That Valve is toast. so if tearing it up to replace 1 valve just as well replace all of them..
Since you have the head off you will see a rust ring at each piston ring so might as well hand hone the cylinders..
See where this is going...
When they set the engine aside >2yrs ago it may have run great. but not being sealed up simple humidity has done its damage. some pistons may have had the valves closed at the time, but others would have valves open. So the air got into those cylinders as well.
The engine has just been exposed to the elements too long to avoid a rebuild.
If you have the knowledge, or at least ability to follow directions in a Shop manual.. Just do a rebuild on your engine, you may even enjoy it.
It'll cost much less than replacing, and unless your getting a low milage late model replacement your only going to have problems a short time down the road with used.
Rebuild yours and you will have a new engine with Zero miles plus any mods you may want like putting an orbital seat on your valve heads rather than cut seats, or a thin 3-layer copper head-gasket over OEM. Roughen your intake ports and smooth up your exhaust ports with a dremmel. Little touches.
But you wont be on the bike tomorrow it'll take as much time as you take.
This engine here is a grenade. You can force it to run most likely, but that's just pulling the pin.
Save your money and return engine ASAP, if they ask why, just show them the pic of that 1 valve and tell them you were looking for a bolt and go engine.
This engine would be a well Im fixing this so might as well do that.. since Ive got this apart I might as well do that.. well... before you know it you've done a rebuild.
Good thing about rebuilding bike engines is you can toss a sheet of plywood on living room floor cover it with a white sheet and rebuild it while watching TV or whatever. then just toss another sheet over the top between working on it.
Take pics as you tear down. and use egg cartons for parts. Label what is what with sharpie on the egg carton every nut and bolt as you tear down makes it easier when building back up after head and block come back from mach shop.
You can really go for it by using CF pistons and rods then rebalancing the crank lightening it up, both raises RPM and HP significantly.(not for beginner) Just saying in passing not knowing your skill level.
A shop manual, pics, being organized, and patience is really all you need for a successful rebuild even for a novice. Plus like I said, it could be fun.. Hardest part is the R&R of engine which you are doing already..

 

Here's the 20 year old engine in my bandit - with 35k miles.




Here's a 954 head that's sitting on my bench, but again, look at the ports...






Look at your ports, see the burnt oil/fuel residue?

 

I think we've "helped" the OP enough. Agreed?