weefek
Well-Known Member
- Local time
- 7:06 PM
- Joined
- May 14, 2022
- Messages
- 706
So, I get my driver's license back in about 1 month. That means I still have a month of relying on my bike for trips into town. After that I can have some real fun with this bike! To start off I'm going to throw my rebuilt new engine on (fresh bearings, blahblah etc see my other thread about it) with proper squish gap and everything and focus on rebuilding the engine I'm currently running. Already have a new jug and piston and bearings and what not in case any of that needs to be replaced. I think eventually maybe V5 phantom85 but who knows what the future holds. Regardless.
Lately (the last... 50 miles or so, I'm at around 500 miles total on my bike/engine) at high rpm (full out) 33mph or so on a 44t rear gear so around 7200~ish rpm (by the maths, I don't have a tach on it) there is a weird clanging noise. I'm not sure how to describe it. I've had a decent amount of experience with automotive 4 stroke engines (ford FE engines, chev 350's, modern VW 4 strokes, subaru weird ass engines, buick V6s, etc) and it doesn't sound like rod knock or anything i've ever heard before. It literally only happens above 7000rpm or so.
I have a feeling it has something to do with the clutch bevel gear / crank bevel gear. When I go over large bumps or gaps in the road the same noise occurs. Everything is tight obviously before anyone asks (motor mounts, head bolts, etc).
The best way to describe it sounds like marbles in the engine. It's definitely not predetonation, I'm running 94 at the moment (because it was the only gas i could get at the time that has no ethanol in it). I've taken the head off a few times and it doesn't look like there is a hot spot (which can also cause pre-det regardless of octane).
Any ideas or has anyone else has this issue and figured it out? I've got my spare engine ready to throw on but I'm worried that this one will die and/or explode on me during a trip into town (around 5 miles one way).
Lately (the last... 50 miles or so, I'm at around 500 miles total on my bike/engine) at high rpm (full out) 33mph or so on a 44t rear gear so around 7200~ish rpm (by the maths, I don't have a tach on it) there is a weird clanging noise. I'm not sure how to describe it. I've had a decent amount of experience with automotive 4 stroke engines (ford FE engines, chev 350's, modern VW 4 strokes, subaru weird ass engines, buick V6s, etc) and it doesn't sound like rod knock or anything i've ever heard before. It literally only happens above 7000rpm or so.
I have a feeling it has something to do with the clutch bevel gear / crank bevel gear. When I go over large bumps or gaps in the road the same noise occurs. Everything is tight obviously before anyone asks (motor mounts, head bolts, etc).
The best way to describe it sounds like marbles in the engine. It's definitely not predetonation, I'm running 94 at the moment (because it was the only gas i could get at the time that has no ethanol in it). I've taken the head off a few times and it doesn't look like there is a hot spot (which can also cause pre-det regardless of octane).
Any ideas or has anyone else has this issue and figured it out? I've got my spare engine ready to throw on but I'm worried that this one will die and/or explode on me during a trip into town (around 5 miles one way).