Oiling issue

[Bandera rider]

I am new to the forum, but have owned my Hawk 250 for a little over a year. I bought it new in February of 2023. I have put 2000 miles on it with no issues. Recently while adjusting the valve lash I noticed the rocker was darker in color, as well as the push rod on the intake side. I cleaned it up put it back together and went on a short ride and somehow bent a valve and lost compression. Ordered a new head assembly and installed it, adjusted valves started it up and have gone on a few short rides. On the last start up noticed a louder tapping noise. Removed valve cover and seems like the same issue is reoccurring. It seems as if the valves are not getting properly lubricated. I have used a compressor to check the passageways in the valve cover to make sure they are clear . Not sure what else to check and fear if I continue to run it I will mess up another head assembly. Any suggestions would be appreciated.

[Megadan]

Leave the valve cover off and crank the engine over with the kill switch off so it doesn't start and verify oil is making it up to the head. Or, do start it and be prepared to kill it if oil does come up so you don't make too big of a mess.

[red2003]

Lack of oil wouldn't cause a bent valve. Sounds like you are not adjusting the valves correctly, as this problem arose after your valve maintenance.

[Bandera rider]

Thank you for the responses. I like the idea of cranking the engine to make sure oil is getting to that point. And yes the bent valve was most definitely my screw up. One day the bike would not start and I narrowed it down to no compression, pulled the valve cover and realized intake valve was not closing so like a total dummy I gave it a little help with a screwdriver. That was probably the reason for the bent valve. However it wasn’t closing because the rocker had seized to the rod that it's supposed to freely pivot on, which is why I believe it is not getting oiled properly.

[red2003]

Thank you for the responses. I like the idea of cranking the engine to make sure oil is getting to that point. And yes the bent valve was most definitely my screw up. One day the bike would not start and I narrowed it down to no compression, pulled the valve cover and realized intake valve was not closing so like a total dummy I gave it a little help with a screwdriver. That was probably the reason for the bent valve. However it wasn’t closing because the rocker had seized to the rod that it's supposed to freely pivot on, which is why I believe it is not getting oiled properly.

Oh, that makes more sense. Hmmm, does sound like something funky going on with lubrication.

[Bandera rider]

Left valve cover off, started up the bike and no oil came up. I am not familiar with how these things pump oil, so unless there is something I am not thinking of my next guess is to tear down the top end looking for some sort of blockage.

[Megadan]

Left valve cover off, started up the bike and no oil came up. I am not familiar with how these things pump oil, so unless there is something I am not thinking of my next guess is to tear down the top end looking for some sort of blockage.

Oil comes directly from the pump and goes straight up through the valve cover through the cylinder and cylinder head via the right rear head stud. If one of the gaskets was installed wrong it would block the oil flow. If I had to guess as to which one, I would say the base gasket. Or somebody put a dowel for the head in that location somehow (less likely.)

[red2003]

Megadan's advice is sound. I'd pull the clutch cover first and verify there isn't an oil pump drive gear issue, but barring that you'll need to start taking off the top end to find where the restriction is. Alternately, you could send a little forced air down the oil gallery from the head and see if it is indeed blocked.

[Bandera rider]

Took off the clutch plate, didn’t seem to be any issues with the gear. Disassembled the top end and did not seem to find any blockage.

[J4Fun]

Just wondering out loud here, the screen in the side drain plug on the left hand side of the motor, is it clean? I’m thinking the screen could be plugged?

[red2003]

With the top end removed, are you getting oil coming out of the right rear head stud hole when spinning the engine over?

[Bandera rider]

I have not checked the screen, but oil change was very recent and I pulled and cleaned it then. And no I did not get oil to come up when when I turned it over, however I did not turn it over much because I was hesitant because I had never disassembled the motor that far before.

[Bandera rider]

I am assuming the plastic gear under the clutch plate is for the oil pump. Is that gear supposed to spin the shaft it is mounted on or spin freely? If it is not supposed to drive the shaft I does see the purpose for the gear.

[red2003]

Yes that is the oil pump gear, and yes it should turn the oil pump shaft. It is NOT an idler gear. If the gear turns, and the pump shaft doesn't, you have found your problem. Unfortunately, that means the rest of the engine hasn't been getting oil either, and you probably have more problems than just noisy valves.

[Bandera rider]

Yeah that shaft is locked up and does not budge. Thanks for all the input, I really appreciate it.

[Megadan]

Yes that is the oil pump gear, and yes it should turn the oil pump shaft. It is NOT an idler gear. If the gear turns, and the pump shaft doesn't, you have found your problem. Unfortunately, that means the rest of the engine hasn't been getting oil either, and you probably have more problems than just noisy valves.

Meh, it will probably be fine. Most of the engine is also splash oiled so it will likely be ok. The valvetrain would be the thing that suffered the most. Worst case, it needs a top end, and those are fairly cheap.

[Megadan]

Yeah that shaft is locked up and does not budge. Thanks for all the input, I really appreciate it.

On the plus side of things, you found the problem and it's a cheap fix.

[red2003]

Meh, it will probably be fine. Most of the engine is also splash oiled so it will likely be ok. The valvetrain would be the thing that suffered the most. Worst case, it needs a top end, and those are fairly cheap.

Except, the cam bearings / lobes and transmission shafts rely on pressurized oil for lubrication. Those would be the areas that are likely worn pretty bad (if not ruined). These have nothing to do with a "top end", so that is far from the worst case.

[Bandera rider]

So can the oil pump be rebuilt or replaced? If so where would I be able to get parts?

[Megadan]

Except, the cam bearings / lobes and transmission shafts rely on pressurized oil for lubrication. Those would be the areas that are likely worn pretty bad (if not ruined). These have nothing to do with a "top end", so that is far from the worst case.

Most of those are also splash oiled for redundancy, like I already stated, so they are still likely ok. The entire bottom end is designed around that concept, intentionally, so it can survive low/no oil conditions without any short term severe damage. Translation: I wouldn't sweat it. That engine assembly will likely give years of service without ever suffering a failure from its brief time with a bad oil pump.

Both the main and counter shaft are partially submerged when the oil isn't circulating. The bottom of the crank counters are also submerged and sling oil. All of the bearings would see enough oil splash to stay lubricated. The cam, being right above and next to the crank also gets splash oiled from below..

Is ther some minor wear damage? It's possible. Enough to have trashed the bottom end? I would bet my 401k it's fine.

As a side. Why does everybody here need to make rude remarks to everything in an argument? It's not necessary.

[Megadan]

So can the oil pump be rebuilt or replaced? If so where would I be able to get parts?

You can easily replace it. They can be often found on ebay. Also found on aliexpress for 6 to 10 bucks plus shipping. It would be a good idea to pull the oil pump to help match it to your application. Gear tooth count and housing shape In particular. Post a couple of pictures of it and I can try to help you match it up.

[red2003]

Most of those are also splash oiled for redundancy, like I already stated, so they are still likely ok. The entire bottom end is designed around that concept, intentionally, so it can survive low/no oil conditions without any short term severe damage. Translation: I wouldn't sweat it. That engine assembly will likely give years of service without ever suffering a failure from its brief time with a bad oil pump.

Both the main and counter shaft are partially submerged when the oil isn't circulating. The bottom of the crank counters are also submerged and sling oil. All of the bearings would see enough oil splash to stay lubricated. The cam, being right above and next to the crank also gets splash oiled from below..

Is ther some minor wear damage? It's possible. Enough to have trashed the bottom end? I would bet my 401k it's fine.

As a side. Why does everybody here need to make rude remarks to everything in an argument? It's not necessary.

I stand corrected on the cam. I totally forgot we're talking about a CG. I agree, the cam is prob fine. Because someone has a differing opinion to yours does not make it rude. And, as an aside, replying to someone's opinion with a "meh...." is very dismissive and rude.

[Megadan]

I stand corrected on the cam. I totally forgot we're talking about a CG. I agree, the cam is prob fine. Because someone has a differing opinion to yours does not make it rude. And, as an aside, replying to someone's opinion with a "meh...." is very dismissive and rude.

I have zero issues with people disagreeing with me. I have every issue with the "tone" of how they disagree, and I took yours as rude and dismissive.

As far as the "meh" goes, if you read into the context and the words you will notice that the "meh" was definitely dismissive, but it was dismissive to what you said, not you. Funny enough, since you just agreed with me it seems the dismissed information was worth dismissing, thus totally appropriate. Sorry I bruised your ego and you felt the need to lash out.

Also, yes, I am often taken as being "rude" by many people because my matter of fact nature and low tolerance for misinformation and narcissism. You can call me any and every name under the sun if it makes you feel better. I will probably agree with you.

[Bandera rider]

https://www.chinariders.net/picture.php?albumid=525&pictureid=2389[/IMG]

[Bandera rider]

https://www.chinariders.net/picture.php?albumid=525&pictureid=2387[/IMG]

[Megadan]

Looks like the nylon gear rounded out inthe middle. Should be a D shape like the shaft. Does the pump turn at all?

The gear is 37 Teeth. There are options on Aliexpress. Might have to wait a week or two, but this is what you need.
https://www.aliexpress.us/item/2251832176071052.html?spm=a2g0o.productlist.main.3 .7ac5shxUshxUJl&algo_pvid=177d1414-4e11-4d06-9b34-550d5e230d27&algo_exp_id=177d1414-4e11-4d06-9b34-550d5e230d27-1&pdp_npi=4%40dis%21USD%2110.99%2110.99%21%21%2110.9 9%2110.99%21%402101c5a717191043252736109e7b55%2163 957343456%21sea%21US%21888865834%21&curPageLogUid=61pTqUGSVM6S&utparam-url=scene%3Asearch%7Cquery_from%3A

A different listing for a bit cheaper. https://www.aliexpress.us/item/2255801158680511.html?spm=a2g0o.detail.pcDetailTop MoreOtherSeller.4.2cdb71mF71mFJL&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=e1d07d60-df72-4ccd-912d-50e81a5584f7&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:e1d07d60-df72-4ccd-912d-50e81a5584f7,tpp_buckets:668%232846%238115%232000&pdp_npi=4%40dis%21USD%218.01%218.01%21%21%218.01%2 18.01%21%402103201917191043381307513e6293%21120000 24281944533%21rec%21US%21888865834%21&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_fro m%3A

You may be able to find one on ebay or amazon with a bit of digging.

[Bandera rider]

The gear shaft was missing a retainer clip and when I pulled the pump apart a piece of it had some how been pulled into the pump jamming and deforming the little aluminum impeller or whatever it’s called. Thought for a moment I might be able to salvage the pump but it no longer spins freely.

[Thumper]

Looks like the nylon gear rounded out inthe middle. Should be a D shape like the shaft. Does the pump turn at all?

The gear is 37 Teeth. There are options on Aliexpress. Might have to wait a week or two, but this is what you need.
https://www.aliexpress.us/item/2251832176071052.html?spm=a2g0o.productlist.main.3 .7ac5shxUshxUJl&algo_pvid=177d1414-4e11-4d06-9b34-550d5e230d27&algo_exp_id=177d1414-4e11-4d06-9b34-550d5e230d27-1&pdp_npi=4%40dis%21USD%2110.99%2110.99%21%21%2110.9 9%2110.99%21%402101c5a717191043252736109e7b55%2163 957343456%21sea%21US%21888865834%21&curPageLogUid=61pTqUGSVM6S&utparam-url=scene%3Asearch%7Cquery_from%3A

A different listing for a bit cheaper. https://www.aliexpress.us/item/2255801158680511.html?spm=a2g0o.detail.pcDetailTop MoreOtherSeller.4.2cdb71mF71mFJL&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=e1d07d60-df72-4ccd-912d-50e81a5584f7&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:e1d07d60-df72-4ccd-912d-50e81a5584f7,tpp_buckets:668%232846%238115%232000&pdp_npi=4%40dis%21USD%218.01%218.01%21%21%218.01%2 18.01%21%402103201917191043381307513e6293%21120000 24281944533%21rec%21US%21888865834%21&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_fro m%3A

You may be able to find one on ebay or amazon with a bit of digging.

Nice find(s).

[Bandera rider]

Oil pump has been ordered, and hopefully the Hawk will be running soon. Thanks again for everyone’s input, I would never have figured it out on my own.