Breaking In After Rebuild

Plukey · 01-30-2019, 05:42 PM

I've gotta admit, didn't think about this. On a previous thread, I discussed clutch replacing, that has been solved. Current issue is white smoke on start up. I did a top end rebuild, new rings and gaskets, had some problems on reinstall. Last two days ive come home from work and I start my bike and I get smoke, defiantly oil burning smell. After it warms up smoke is VERY minimal, none at all... (10-15) minutes, then a quick ride because its COLD park/cool down 2nd day start up same thing SMOKE! So I have no idea what's next, open back up again?

I did lube the side walls with oil to get the piston back in. im confident the (99%) rings are in and placed correctly...the gaps were offset to prevent any oil coming up. I did noticed a slight groove on the side wall, other than that it had a pretty cross hatch...Need ideas please?

200cc Zongshen GY-A FMF Muffler 30mm Mukini

**JerryHawk250** · 01-30-2019, 05:56 PM

Did you replace the valve seals? It takes very little oil on the exhaust side to cause a lot of smoke.

Plukey · 01-30-2019, 06:17 PM

Quote:

Originally Posted by JerryHawk250

Did you replace the valve seals? It takes very little oil on the exhaust side to cause a lot of smoke.

No, I didn't touch the valves. Prolly should have, but no smoke before I did the job. I only opened it because I wasn't sure due to purchasing with no odometer...ive had it a few years figured why not...I purchased the kit off Amazon 69mm piston with rings and gaskets... I re used the original piston.

512customs · 01-30-2019, 08:16 PM

So many things it could be... valve seals, rings not set correctly, bad gasket letting oil seep into combustion chamber, scored cylinder, etc

Megadan · 01-30-2019, 08:30 PM

When you did the new rings did you hone the cylinder?

Plukey · 01-31-2019, 10:44 AM

No...and I’m learning from these mistakes. I also thought that oiling down the walls was right at time. I learned that the rings will never set. I have it back on the bench apart again and I’m slowing down and I’m researching this site and other avenues...I want to do it right. I’ve ordered new valve seals, can I re-use the original valves if they look good? I’m purchasing a flex Hoan tool today. I noticed they offer different grit, (80 or 120) there is a small score. When I put it all back together, I’ve read so many different ways to break it in, run slow / run slow then really hard...& really hard and let cool down. So thoughts on that?

**JerryHawk250** · 01-31-2019, 11:35 AM

I would use a hone with the straight stones to evenly hone the cylinder. https://www.autozone.com/loan-a-tool...zer/555581_0_0#
When reassembling make sure to clock the rings at 120 degree intervals.

Valves can be reused but would suggest to lap the valves.

512customs · 01-31-2019, 12:30 PM

If you can feel the score in the cylinder with your finger nail, you should probably just replace the cylinder. They are cheap, and I don’t think you can get over sized pistons for these motors (I could be wrong), but if that’s the case boring the cylinder is out of the question.

Plukey · 01-31-2019, 12:54 PM

Quote:

Originally Posted by 512customs

If you can feel the score in the cylinder with your finger nail, you should probably just replace the cylinder. They are cheap, and I don’t think you can get over sized pistons for these motors (I could be wrong), but if that’s the case boring the cylinder is out of the question.

Yes, I definitely can feel with my finger nail...! Ugh 😑

Megadan · 01-31-2019, 02:25 PM

If the piston is marred up at all, you should replace it too.

You can order a new cylinder, base, and head gasket from CSC for a bit less than 50 bucks. Toss in a new piston, pin and rings for about another $20ish.

Also, it is always a good idea to put a little oil on the cylinders when installing new rings. The will set just fine, and it protects them from dry start damage. The best thing you can do is wash that cylinder and get as much of the machining swarf off of the bore as you can, finishing with a solvent wipe down - preferably wd40 or kerosene - until the rag comes up clean. From there, wipe it down with motor oil when installing the new piston and rings. I usually go a step further and smear it with assembly lube.

The rings will remove the oil on their own and bed in just fine. That is part of their job after all.

You can definitely inspect the valves. The main thing to look for is valve guide wear. Honestly, unless your engine has a ton of miles on it they are likely fine.

**JerryHawk250** · 01-31-2019, 03:01 PM

Quote:

Originally Posted by Megadan

If the piston is marred up at all, you should replace it too.

You can order a new cylinder, base, and head gasket from CSC for a bit less than 50 bucks. Toss in a new piston, pin and rings for about another $20ish.

Also, it is always a good idea to put a little oil on the cylinders when installing new rings. The will set just fine, and it protects them from dry start damage. The best thing you can do is wash that cylinder and get as much of the machining swarf off of the bore as you can, finishing with a solvent wipe down - preferably wd40 or kerosene - until the rag comes up clean. From there, wipe it down with motor oil when installing the new piston and rings. I usually go a step further and smear it with assembly lube.

The rings will remove the oil on their own and bed in just fine. That is part of their job after all.

You can definitely inspect the valves. The main thing to look for is valve guide wear. Honestly, unless your engine has a ton of miles on it they are likely fine.

He doesn't mention in this thread but from what I recall he has a CB250 engine so the gaskets will not work from CSC.

Megadan · 01-31-2019, 04:01 PM

Quote:

Originally Posted by JerryHawk250

He doesn't mention in this thread but from what I recall he has a CB250 engine so the gaskets will not work from CSC.

Ahh, well if it's an OHC engine, then nothing from CSC will work. The prices for the same parts through Aliexpress are about the same though.

Plukey · 01-31-2019, 04:08 PM

Stamped inside the engine reads cb200 outside the cylinder head reads 198cm3 69mm piston...my odometer only reads 1800 it’s an 04 and I purchased from the 2nd owener that claimed it had 1000 or less.

I’ve already purchased new rings and a piston, only place I’ve seen the cylinder is AliExpress 71.00

Plukey · 01-31-2019, 05:07 PM

Here’s the line in the cylinder.

**JerryHawk250** · 01-31-2019, 05:34 PM

It's hard to tell from the picture how deep those scratches are. If they are not too deep it is possible to hone them out as long as the ring gaps are still in tolerances after you are done. I've done it before but had oversized rings that I ground to get the right gap. It's worth a try. Worst that can happen is you will have to get a cylinder.

01-30-2019, 05:42 PM	#1
Plukey Join Date: Nov 2011 Location: Poquoson Va Posts: 73	Breaking In After Rebuild I've gotta admit, didn't think about this. On a previous thread, I discussed clutch replacing, that has been solved. Current issue is white smoke on start up. I did a top end rebuild, new rings and gaskets, had some problems on reinstall. Last two days ive come home from work and I start my bike and I get smoke, defiantly oil burning smell. After it warms up smoke is VERY minimal, none at all... (10-15) minutes, then a quick ride because its COLD park/cool down 2nd day start up same thing SMOKE! So I have no idea what's next, open back up again? I did lube the side walls with oil to get the piston back in. im confident the (99%) rings are in and placed correctly...the gaps were offset to prevent any oil coming up. I did noticed a slight groove on the side wall, other than that it had a pretty cross hatch...Need ideas please? 200cc Zongshen GY-A FMF Muffler 30mm Mukini
	0

01-30-2019, 05:56 PM	#2
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,580	Did you replace the valve seals? It takes very little oil on the exhaust side to cause a lot of smoke. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	2

01-30-2019, 08:16 PM	#4
512customs Join Date: Dec 2018 Location: Illinois Posts: 44	So many things it could be... valve seals, rings not set correctly, bad gasket letting oil seep into combustion chamber, scored cylinder, etc __________________ Toys: 2017 Hawk 250 (new in 2019) 1999 Softail, Ultima frame, s&s 113” @ 129rwhp 2005 Honda trx450r full mx build 1986 Honda trx250r xc build on race gas 1998 Kawasaki kx250 1995 Polaris xplorer 400 4x4 1997 Jeep Wrangler 3.5” on 33s
	1

01-30-2019, 08:30 PM	#5
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,044	When you did the new rings did you hone the cylinder? __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	0

01-31-2019, 11:35 AM	#7
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,580	I would use a hone with the straight stones to evenly hone the cylinder. https://www.autozone.com/loan-a-tool...zer/555581_0_0# When reassembling make sure to clock the rings at 120 degree intervals. Valves can be reused but would suggest to lap the valves. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	1

01-31-2019, 10:44 AM	#6
Plukey Join Date: Nov 2011 Location: Poquoson Va Posts: 73	No...and I’m learning from these mistakes. I also thought that oiling down the walls was right at time. I learned that the rings will never set. I have it back on the bench apart again and I’m slowing down and I’m researching this site and other avenues...I want to do it right. I’ve ordered new valve seals, can I re-use the original valves if they look good? I’m purchasing a flex Hoan tool today. I noticed they offer different grit, (80 or 120) there is a small score. When I put it all back together, I’ve read so many different ways to break it in, run slow / run slow then really hard...& really hard and let cool down. So thoughts on that?
	0

01-31-2019, 12:30 PM	#8
512customs Join Date: Dec 2018 Location: Illinois Posts: 44	If you can feel the score in the cylinder with your finger nail, you should probably just replace the cylinder. They are cheap, and I don’t think you can get over sized pistons for these motors (I could be wrong), but if that’s the case boring the cylinder is out of the question. __________________ Toys: 2017 Hawk 250 (new in 2019) 1999 Softail, Ultima frame, s&s 113” @ 129rwhp 2005 Honda trx450r full mx build 1986 Honda trx250r xc build on race gas 1998 Kawasaki kx250 1995 Polaris xplorer 400 4x4 1997 Jeep Wrangler 3.5” on 33s
	1

01-31-2019, 02:25 PM	#10
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,044	If the piston is marred up at all, you should replace it too. You can order a new cylinder, base, and head gasket from CSC for a bit less than 50 bucks. Toss in a new piston, pin and rings for about another $20ish. Also, it is always a good idea to put a little oil on the cylinders when installing new rings. The will set just fine, and it protects them from dry start damage. The best thing you can do is wash that cylinder and get as much of the machining swarf off of the bore as you can, finishing with a solvent wipe down - preferably wd40 or kerosene - until the rag comes up clean. From there, wipe it down with motor oil when installing the new piston and rings. I usually go a step further and smear it with assembly lube. The rings will remove the oil on their own and bed in just fine. That is part of their job after all. You can definitely inspect the valves. The main thing to look for is valve guide wear. Honestly, unless your engine has a ton of miles on it they are likely fine. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	2

01-31-2019, 04:08 PM	#13
Plukey Join Date: Nov 2011 Location: Poquoson Va Posts: 73	Stamped inside the engine reads cb200 outside the cylinder head reads 198cm3 69mm piston...my odometer only reads 1800 it’s an 04 and I purchased from the 2nd owener that claimed it had 1000 or less. I’ve already purchased new rings and a piston, only place I’ve seen the cylinder is AliExpress 71.00
	1

01-31-2019, 05:34 PM	#15
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,580	It's hard to tell from the picture how deep those scratches are. If they are not too deep it is possible to hone them out as long as the ring gaps are still in tolerances after you are done. I've done it before but had oversized rings that I ground to get the right gap. It's worth a try. Worst that can happen is you will have to get a cylinder. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
	3