Valve cover clearance question

[SpudRider]

I'm sorry to hear of this issue. Thanks for warning future potential buyers.

[BlackBike]

Update... my feeler g. set didn't go down to the book specified .05mm so I spent most of the day driving to 3 different towns finally found http://shop.advanceautoparts.com/p/a...0528/9020756-P in corpus christi tx. This set is not exact but close enough to the paper thin tolerance called for.

Couple of questions left.

Is the intake valve on the carburetor side , and exhaust valve on the header side ?

Do I measure the gaps when the tops of both rocker arms are in the up most position at tdc?

Been a long day

[SpudRider]

Originally Posted by BlackBike

Update... my feeler g. set didn't go down to the book specified .05mm so I spent most of the day driving to 3 different towns finally found http://shop.advanceautoparts.com/p/a...0528/9020756-P in corpus christi tx. This set is not exact but close enough to the paper thin tolerance called for...

Here is the Harbor Freight, feeler gauge set I use for all my motorcycles.

http://www.harborfreight.com/catalog...=feeler+gauges

Originally Posted by BlackBike

...Couple of questions left.

Is the intake valve on the carburetor side , and exhaust valve on the header side ?...

Yes.

Originally Posted by BlackBike

Do I measure the gaps when the tops of both rocker arms are in the up most position at tdc?...

Which side do you consider the "top?"

You want to adjust the valve lash when both rocker arms are loose, and not contacting the valve tappets. This will occur when both pushrods are at the lowest position.

[BlackBike]

Spud said..."You want to adjust the valve lash when both rocker arms are loose, and not contacting the valve tappets. This will occur when both pushrods are at the lowest position."

Ok, so that is the opposite of what I thought. So it is when the rocker arms are all the way down (meaning plunging down into the cylinder)? Thanks


Also, I looked at that set on line but the specs only showed inch specs so I passed. That was the one I should have got. I seem to remember you posting that in the past now too.

[SpudRider]

Originally Posted by BlackBike

Spud said..."You want to adjust the valve lash when both rocker arms are loose, and not contacting the valve tappets. This will occur when both pushrods are at the lowest position."

Ok, so that is the opposite of what I thought. So it is when the rocker arms are all the way down (meaning plunging down into the cylinder)? Thanks...

No, you don't way the rocker arms plunging down on the valves, forcing them into the cylinder. You want both rocker arms loose, and not contacting the top of the valves.

[Mudflap]

I've noticed a difference in valve cover design on my CG engines. The Zongshen and Taotao have tall and squared off covers while my Lifans are shorter and taper down on the sides. Yours looks tall and squarish like the Zongshen. I wonder if a Lifan cover would fit and give you clearance to remove it without dropping the engine down.

Just measured clearance between the frame and valve cover on the Lifan, 5/8 inch. The cover can be removed without lowering the engine.

[BlackBike]

Originally Posted by Mudflap

I've noticed a difference in valve cover design on my CG engines. The Zongshen and Taotao have tall and squared off covers while my Lifans are shorter and taper down on the sides. Yours looks tall and squarish like the Zongshen. I wonder if a Lifan cover would fit and give you clearance to remove it without dropping the engine down.

Just measured clearance between the frame and valve cover on the Lifan, 5/8 inch. The cover can be removed without lowering the engine.

Thanks, this is a Lifan engine. I need to look for covers to see if it would help.

[Mudflap]

It's quite possible the 250 needs the larger valve cover for rocker arm clearance.

[FastDoc]

Sorry to hear about your woes. Looks like a design flaw made a pretty simple job pretty aggravating.

At least now that you knoe the 'secret handshake' it will only take half as long next time, and these motors hold their clearances quite a while.

[Weldangrind]

Originally Posted by Mudflap

I've noticed a difference in valve cover design on my CG engines. The Zongshen and Taotao have tall and squared off covers while my Lifans are shorter and taper down on the sides. Yours looks tall and squarish like the Zongshen. I wonder if a Lifan cover would fit and give you clearance to remove it without dropping the engine down.

Just measured clearance between the frame and valve cover on the Lifan, 5/8 inch. The cover can be removed without lowering the engine.

Exactly what I was thinking. I posted pics of both types a few years ago, but I can't remember where.

[BlackBike]

Well folks after a marathon session I decided I may as well address the valve cover clearance issue now while I have the motor dropped. This has been a real learning rxperience (not one I wanted so soon however). I cut out that top frame weld seam line which was causing the clearance issue and also ground off the cooling fins of the valve cover. The fins were removed from the left to help removal to the right side. I used a Dewalt metal cutting blade on a reciprocating saw and went at it. Didnt look so nice after this was done but I continued on with the welding. One time, somone said said something about the steel quality on these bikes was not so good. I just think it was due to the steel being thin, and went threw several settings on my wire feed welder till I got it dialed in. Basically had to set it down to lowest setting and used daube and move technique similar to auto body welding. And upside down welding is never fun.

After I finished welding , repainted with rust converter primer and heavy brush coat of satin BBQ black paint I had on hand. Valve cover was ground down as much as possible without damaging that top oil channel. Painted with life fitness platinum metallic spray and over coated everything with clear gloss spray. I wanted to make sure to try to stop any rust as much as possible in our humid climate.

Spud, I appreciate your patience with me concerning my value clearance questions. My intake was set correctly at around .05mm but my exhaust was at .0mm. Hence this was the tapping sound I always reported hearing since it was new, just not from the exhaust valve. I read everything I could and especially the csc blog on the subject and figured it out. I set the exhaust valve at about .07mm.

I put everything back together and decided not to try the carb. Mod. Didn't want to chase multiple issues in case I got the valve clearance wrong. Then I wouldn't know what was causing the problem, carb or valves.

All back together and started right up no harm no foul. Seems to run the same but may be breathing better with correct exhaust clearence. Top speed has gained mabey 2 MPHbut not sure if that was just because it was a good high pressure atmosphere day we are having now (noticed how atmosphere effects how it runs)

So,,, according to number 1, first rule of China rider forum (it didn't happen if no pics), here are the compressed pics (found a pic compressor app)

[BlackBike]

Ps, I didn't test removing the cover after I reinstalled the motor to see if I solved the frame clearence issue. I had already installed the value cover and was already on the way back together with everything. If it didn't solve the clearence problem for next time, there was nothing else that can be done about it but drop the motor again anyway......

Glad thats over, now back to riding . Have my riders safety course this weekend. Don't tell anyone I have already put over 1000 miles on my bike .

[BlackBike]

Originally Posted by Weldangrind

Exactly what I was thinking. I posted pics of both types a few years ago, but I can't remember where.

Thanks for your input. I sure tried six ways to Sunday to get that cover off but was blocked at every orientation. Mabey I was missing something but I could see no way forward without lowering the engine.

[BlackBike]

Originally Posted by FastDoc

Sorry to hear about your woes. Looks like a design flaw made a pretty simple job pretty aggravating.

At least now that you knoe the 'secret handshake' it will only take half as long next time, and these motors hold their clearances quite a while.

Thanks doc,

I did skin my middle finger with the grinder a bit. Since it was my middle finger, this was a fitting tribute to who ever decided to put this Lifan in this frame (it's a super nice balanced motor however).

Now,Someone will probably come out and say, "all you had to do was..."

[2LZ]

Nice to see you got it done! There's some good clearance there now.....