Re: 1984 Yamaha QT50 - smokes a lot and loses power on ride

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> E BinOH Wrote:

> -------------------------------------------------------

> Seems like 90psi may be a little low as far as compression, but I'd need

> to look that up. I was initially thinking the rings could be worn or

> perhaps your carb could need adjusting (or your oil mix is wrong), but

> without knowing your setup, that's a little hard to tell.

>

> For the cylinder, there a TON of chinese QT/PW50 knock off cylinders all

> over the place on the internet. Cheap. Some are 50cc, others are 70cc

> "big bore" kits. Quality seems to vary and the castings appear to be

> rough, but I've heard of a few people with pretty good results running

> them. Jimmy C...are you out there?

>

> With a 70cc kit, you'd probably have to take a closer look at your

> carb.. upjet for sure if not replace with something slightly larger.

Originally thought same that 90psi seemed low but manual says 6:1 which is roughly 88.17 as acceptable spec for compression.

I’ll be checking the oil pump to make sure its not sticking when throttle is off and sending more oil into the carb.

Everything is stock on the bike and prefer to keep it as close to stock as possible knowing cylinders are most likely going to need to be aftermarket.

I’ll have to take the cylinder off to fix the jb weld on the exhaust port and what I suspect is probably a broken exhaust bolt so I’ll check for pitting when its off. Would also be a good time to just swap it out entirely. Amazon has a kit made by Niche but not sure if its any good.

This single post is part of a larger thread. Start from the top or view this post in context.
Subject Written By Posted
  1984 Yamaha QT50 - smokes a lot and loses power on rideTopic by: S C S C 06/11/21 08:58AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: E BinOH E BinOH 06/11/21 10:50AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/11/21 11:01AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/11/21 12:26PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/11/21 01:36PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: E BinOH E BinOH 06/11/21 01:46PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/11/21 04:06PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: B F B F 06/11/21 12:14PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/11/21 01:32PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: b to the eff b to the eff 06/11/21 01:34PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/11/21 04:14PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: Ron Peek Ron Peek 06/11/21 04:14PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: Ron Peek Ron Peek 06/11/21 04:29PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/11/21 04:43PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: B F B F 06/11/21 04:53PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/11/21 06:46PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: campeona del mundo campeona del mundo 06/11/21 06:53PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/11/21 08:21PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: punkrock randy punkrock randy 06/11/21 08:17PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/12/21 10:47AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/12/21 01:22PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/12/21 02:13PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/12/21 04:27PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/12/21 05:12PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/12/21 05:31PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/13/21 08:57AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: b to the eff b to the eff 06/12/21 04:40PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/12/21 04:55PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: b to the eff b to the eff 06/13/21 11:23AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/13/21 12:13PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/13/21 08:42PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/13/21 08:58PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/14/21 08:04PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/14/21 09:01PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/15/21 07:43AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: P D P D 06/15/21 08:40AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: ken gilbert ken gilbert 10/10/21 07:39AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: b to the eff b to the eff 10/10/21 11:56PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 10/11/21 09:35AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/16/21 06:58PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/17/21 11:33AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: Born to be WillD Born to be WillD 06/17/21 12:24PM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: S C S C 06/20/21 09:27AM
  Re: 1984 Yamaha QT50 - smokes a lot and loses power on rideRe: Billy Mild Billy Mild 10/10/21 06:52PM

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