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#1 |
Join Date: Feb 2021
Posts: 994
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I think I have had a roller cam follower come apart.
I have ran the wheels off my Hawk every since I got it, but especially after warning the motor up. I have put about 2,500 miles on it since doing the motor some months ago. It's performed great, but today, as I was getting ready to park at Walmart, I heard two little metallic pings within seconds of each other. I thought it sounded like I ran over something, then as I was pulling into a parking spot , the motor got noisy, almost like a loud clicking, almost like a card in a bicycle spokes, but louder. I made absolutely sure that I hadn't lost oil, and drove it home on the back roads, about 6 miles, or so. I didn't try to make much power, but the motor ran alright, and would get noisier, and quieter, and occasionally act like the chain , or a transmission gear would jump a tooth. I figured it was probably a transmission issue, at worst, or the centrifugal oil filter coming loose at best. I figured I would pull the valve cover, before taking side cases off, and my exhaust valve has at least an 1/8th inch, or possibly 3/16th inch of clearance. I keep the valves adjusted regularly, and the locknut is still tight, everything looks normal under the valve cover, other than the exhaust valve having too much clearance. I have a feeling it would be a mistake to adjust the valve, and try starting it. I don't think the bike would have started good, or ran decent if the exhaust valve wasn't seating right, so the only thing I can figure is a bent pushrod, or the roller wheel coming off the follower. The bike was just at a slow unstressed speed when it happened. I think it's the roller, because I think that bouncing around in the works was probably my noise.
It's miserably hot here, so I may just slap the stock motor from my parts bike on it for now. I honestly have been thinking about selling either the Hawk, or KPX, because they both get used in about the same way now. I almost regretted doing the motor, and gearing, and tire type changes to the Hawk, because I got the KPX to be more if a road bike, with the knowledge that the Hawk was more of a back road bike, BUT, I ended up using it exactly like the KPX. I probably will eventually fix my warmed up motor, but I won't be in too much hurry. I will probably also go back to knobbies on the Hawk when the 50/50 tires wear out. I am grateful it happened before I put it up for sale, because if someone had bought it, and it had engine trouble soon after, They would think I was a crook. LOL |
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#2 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
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The only way to really know would be to take things apart. If the roller follower roller did collapse it would be pretty obvious. Motocult sells the WGK roller followers, but be warned they are not cheap compared to the random cheap ones you can find on ebay or aliexpress. https://motocultparts.com/products/u...43550418206919
Thankfully, so far, I haven't had a problem with mine even with the big duration cam I am using.
__________________
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 |
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#3 | |
Join Date: Feb 2021
Posts: 994
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#4 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
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__________________
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 |
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#5 | |
Join Date: Feb 2021
Posts: 994
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#6 |
Join Date: Feb 2021
Posts: 994
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It is the cam follower, and it's chewed up my cam gear, and almost certainly the crank gear. I would guess the time I was accelerating hard, climbing the hill, and thought the chain skipped a little was actually the first bearing coming out, and going through the cam, and crank gears, and yesterday the rest came out.
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#7 |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
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That sucks. This is the first roller follower failure I have seen.
On the plus side, the cam and crank gears are cheap. You can also remove the gear on the crank without splitting the cases. It will take an interesting gear puller with longer arms but a narrow width, but it can be removed. Just make sure to put the key facing 12 o'clock so it doesn't fall into the case.
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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 |
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#8 |
Join Date: Aug 2020
Location: Australia
Posts: 1,408
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I tried the rollers on a stock cam...
they were quieter at idle and cold start but unnoticeable when riding/operational. I went back to stock flat followers after seeing witness marks on the cam which I put down to the increased reciprocating mass of the roller heads...They were DYNOP aliexpress brand... I felt no performance gain using them. If anything it felt like I lost power at the top end. So made the recommendation to others not to use them with the stock cam along with the fact the stock pushrods were to long...which meant either shorter rods or shimming up the valve rocker assembly. |
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#9 | |
Join Date: Feb 2021
Posts: 994
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#10 | |
Join Date: Apr 2017
Location: Omaha, NE
Posts: 8,100
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The pushrod problem is interesting. I notied no difference on mine.
__________________
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 |
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#11 |
Join Date: Aug 2020
Location: Australia
Posts: 1,408
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The pushrod length seemed only an issue with a stock cam. I compared the cam that came with the rollers as the kit to the stock cam after dissambly and found the supplied cam to be smaller overall with less lift and rounder profile...
the issue with was valve adjusters went out with stock pushrods. |
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