r/motorcyclerepair

Honda SP160 after 4700 km: Good engine days, bad engine days and some service centre issues
▲ 9 r/motorcyclerepair+1 crossposts

Honda SP160 after 4700 km: Good engine days, bad engine days and some service centre issues

https://preview.redd.it/qz11w8qf8oth1.png?width=438&format=png&auto=webp&s=edfcbc9687a5fe9821a45b8cbdd87accf304e719

I’ve had my Honda SP160 for 11 months now and have ridden around 4700 km. It’s basically a weekend toy for me rather than a daily commuter. Whenever I take it out, I usually ride around 40–50 km, and I ride it fairly enthusiastically, usually keeping it around 4–7k RPM.

A few things I’ve noticed during ownership:

  • Mileage: Around 43 kmpl before the first service, and around 50 kmpl after the first service.
  • I generally enjoy riding the bike at higher revs rather than shifting early.

Some service centre issues

When I took delivery, there was an issue with the fuel cap/lock. Initially, the service centre told me that it was normal and that’s just how the bike was. Later, they accepted the issue and replaced all the locks under warranty.

When they did the lock replacement, they apparently didn’t put back all the clips on the right-side fairing properly. I didn’t notice it immediately, but later the fairing started making noises. When I checked, I found that one of the fairing clips was out of position and was almost broken.

I took it back to the service centre (Shymas Honda, Kerala), but they refused to acknowledge that it happened because of their work. Instead, they simply put the nearly broken clip back into place.

The main issue: "good engine days" and "bad engine days"

This has been happening basically since I got the bike.

Some days, the engine feels extremely smooth. I’d call these my good engine days:

  • Very smooth engine
  • Linear power delivery
  • Crisp rev matching
  • Very little vibration/NVH
  • Overall the bike feels refined ,predictable, like how a honda should be

Then there are bad engine days:

  • Noticeably higher NVH/vibration, especially above 4k RPM
  • Power delivery feels rougher
  • Rev matching becomes much less consistent
  • Sometimes I end up over-revving during rev matching even though my throttle input is basically the same
  • I can also feel a slight forward surge after rev matching

Initially, I thought the higher NVH might simply be because the chain was dirty. Later I started using Motul C1 and C2 regularly, but I didn’t notice any real difference between the good and bad days, so I don’t think the chain is the cause.

The strange part is that it seems to depend on how I start the ride.

If I let the bike idle normally after starting, with the auto-choke operating, the chances of getting a bad engine day seem much higher.

However, if I give the throttle a few small blips while the auto-choke is active, basically until the initial throttle lag disappears, the bike will most likely have a good engine day.

Another thing I noticed is that if I’m already riding and it happens to be a bad engine day, I can usually turn the engine off, wait around 5 minutes and restart it, and suddenly it feels normal again.

This has happened enough times that I don’t think it’s just placebo.

I’ve already mentioned this issue to the Honda service centre, but they couldn’t really figure it out or fix it. Honestly, I suspect it could be related to EFI/sensor behaviour, but I don’t know enough to say for sure.

There has never been a check-engine light.

High-speed stability

One other thing I’ve noticed is that at around 90–100 km/h on WOT, the front end feels very light and somewhat unstable.

I’m not sure whether this is normal for the SP160, something related to tyre pressure(i always check the tyre pressure every 2 weeks)/suspension, or just the characteristics of the bike, so I’d like to hear from other SP160 owners.

Overall, I actually like the bike quite a lot. The good engine days are genuinely very enjoyable, which is why the inconsistency is so frustrating.

SP160 owners: have any of you experienced the good-engine-day/bad-engine-day issue? Especially the part where switching the bike off for a few minutes seems to fix it? And has anyone experienced the front end feeling light around 90–100 km/h?

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u/Ashamed_Material5209 — 8 days ago
▲ 5 r/motorcyclerepair+1 crossposts

Engine mount bolt won’t back out

I was attempting to remove my crash bars. When I tried to remove the large bolt in the centre of the photo next to my gremlin bell, it started to come out and then stopped. I couldn’t tighten or loosen it. All other bolts connecting to it were loosened to try to alleviate any tension on it. I thought the engine might be binding on it, so I put a jack under it and tried to relieve some pressure. That didn’t work. I tried heating it, nothing.

I imagine the steel bolt is much harder than the cast aluminum, so I don’t want to crack the case trying to back it out.

Any suggestions?
——

UPDATE: the bolt is out! Went to the shop this morning. The mechanic loosened all other mounting bolts, put a jack under the engine, then used a breaker bar to force it out. It came out with a little bit of aluminum on the thread at the tip of the bolt. It was close to breaking the bolt, but didn’t! He cleaned up the threads on the bolt, chased the inside threads, and it went back in like butter.

For the record, it wasn’t cross threaded, but almost like the original threading wasn’t clean or something, maybe aluminum shavings were still inside it. It was not an issue of the crash bars messing up the bolt or anything. So problem solved without a helicoil. Hooray!

u/ardvarkbark — 11 days ago

Need help with carb issue

04 yamaha road star idles fine(little high have to adjust) but when I twist throttle she pops and then revs up. I have vance hines and k&n air filter setup. Adjusted jets 172.5 main 40 pilot, carb is clean. Air fuel screw is about 3.5 turns out what I missing here, its probably something stupid that im overlooking. Gonna try little propane around carb boots next to check for vacuum leak. Any help is appreciated thanks. On lunch break at work right now so I'll have to wait to get home to try anything.

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u/Nickm19 — 12 days ago