R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Nitro Off-Road

Reply
 
Thread Tools Search this Thread
Old 04-25-2009, 10:52 AM   #1
Tech Initiate
 
boatsnhoes's Avatar
 
Join Date: Apr 2009
Location: S. Texas
Posts: 31
Default Kyosho GXR-28

Need some advice. I bought a used Kysho st-us off of ebizzle, and supposedly had just been broken in and run a few times then put away. RIIIIIGGHHHT. The car looked great so I bought it. Got it home, (looked good, although dirty) and started it, or should I say tried to start it. I put fuel in it, checked glow plug, set the base settings and pulled, pulled, pulled and it fired up. Cool. But almost immediately it was hot as hell. It idled for about 10 secs and shut off. I richened it up a little and tried again, couldnt get it to start to save my life. Put it away and messed with my other truggies and waited for my new temp gun to come in before I messed with it any more. So today, I go at it again, same thing. try and drive it and it will stay running if you dont let it idle, but it got up to about 150 in about 10 seconds of mid range running. Then it shut off and would NOT restart.

The other thing, not related to the engine, is it seems to have trouble getting fuel up the the carb. If I plug the pipe and pull the starter with the fuel line unhooked, it comes out, but as soon as I stop pulling, it drains back to the tank. I would think that would only happen if I let off the pipe. When hooked up and the pipe plugged, the fuel takes forever to get up to the carb, much slower then other vehicles I have. I cant find any leaks on the tank though, I pinched the out line and blew in the in line and it held, so must not be anything. Anyway....

So off comes the head, pipe, pull start, and back plate, and I find the oil laying around inside is gray. Uh oh. Pull out the piston/sleeve and I can push the piston about 1/8 inch up past the top of the sleeve. No good. Pop the flywheel and the front bearing is covered in goo. Wipe it off, pop out the crank and find the area all the way around the fuel intake port is scratched to hell, probably what created the shavings that turned the oil gray.

Obviously the guy BS'd me about how much it had been run, and it is pretty much toast. My questions are:

Is this engine fixable? I mean, new crank (or can I polish it up with emory cloth or super fine sand paper) New piston/sleeve (or should I send it off for a re-pinch/whatever they do to them) Rod? (looks ok, nothing obvious anyway) Bearings?

Or

Is the GXR-28 not a good powerplant? Should I invest in something better?

I am obviously trying to keep costs down as I already paid to much for the thing to begin with ($315, doh!) and I am also considering just cutting my losses and selling it as is. The truck looks killer, but is obviously an entry level vehicle as the components on it are pretty cheap. Give me some opinions on what you guys would do in my shoes. Thanks!
boatsnhoes is offline   Reply With Quote
Old 04-26-2009, 03:56 PM   #2
Tech Initiate
 
boatsnhoes's Avatar
 
Join Date: Apr 2009
Location: S. Texas
Posts: 31
Default

Anyone? Trying to make a decision here and need advice. Thanks!
boatsnhoes is offline   Reply With Quote
Old 04-29-2009, 01:52 PM   #3
Tech Regular
 
Join Date: Nov 2008
Location: Virginia, USA
Posts: 480
Trader Rating: 3 (100%+)
Default

Quote:
Originally Posted by boatsnhoes View Post
Obviously the guy BS'd me about how much it had been run, and it is pretty much toast. My questions are:

Is this engine fixable? I mean, new crank (or can I polish it up with emory cloth or super fine sand paper) New piston/sleeve (or should I send it off for a re-pinch/whatever they do to them) Rod? (looks ok, nothing obvious anyway) Bearings?

Or

Is the GXR-28 not a good powerplant? Should I invest in something better?

I am obviously trying to keep costs down as I already paid to much for the thing to begin with ($315, doh!) and I am also considering just cutting my losses and selling it as is. The truck looks killer, but is obviously an entry level vehicle as the components on it are pretty cheap. Give me some opinions on what you guys would do in my shoes. Thanks!
Fast answer: yes, no, and get something else

Long answer: The motor had serious issue in terms of quality parts. The bearing in the motor were crap and and so were the O-rings in the carburator. That was how Kyosho cut cost to keep price low. It sounds like the damage is done!

Unless you know someone that is good with a dremmel, knows alot about nitro engines, and will work for peanuts, then you'd be better off getting new enging (not Kyosho..mind you) The money spent to repair it ($150-200)could get you a quality buggy engine to bash around with. If you want race competetively or be the fastes kid on the block then you're gonna have to come up with more duckets(cash)$300+)The new GXR-28sg fixed alot of the previous problems but is more geared to on-road. Check the Want To Buy section here on the forum or head over to the engine section at www.amainhobbies.com

Hope this helps
Kyo83 is offline   Reply With Quote
Old 04-29-2009, 03:15 PM   #4
Tech Initiate
 
boatsnhoes's Avatar
 
Join Date: Apr 2009
Location: S. Texas
Posts: 31
Default

Thanks for the reply!

Well, I was going to put it back together the other night and found the HSN housing was veryloose, and that is more then likely what is causing my lean condition/engine damage/fuel delivery problem. I think what happend was when I tightend it down to set the base settings, it was slightly loose, so when I was tightening it it turned enough to tighten, then allowed the need to close all the way down, but when I went to open the needle (richen it) the whole hosuing turned out 4 times rather then the needle. So it was getting a ton of air and very little fuel. So I tightend it up and decided to see what I could do with it. I chucked up the crank in my drill and hit it with 1000 grit sand paper, hit the inside of the crank case with the fine dremel bit, polished up the inside of the case with aluminum polish and the buffing bit on the dremel, cleaned the daylights out of the bearings with denatured alky, lubed them all up and everything seems to turn with no problems. I then sent out the piston/sleeve for resizing. For $25 you cant beat it, and the guys feedback on ebay for his procedure is nothing but good stuff.

We will see if it works, if not I am going to go a different route. I already own an 8ight T, and Ofna Mutilator and a Lightning truggy and although the Kyosho is probably the best looking one, it is nowhere near as capable based on its components.

Thanks very much for the info, that is exactly what I was looking for...
boatsnhoes is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Bendigo..Vic.. On Road Car Club VoneSkip Australian Racing 17215 08-16-2017 11:12 PM
GT class--buggy-based on road! duneland Nitro On-Road 9643 11-16-2016 03:11 AM
RC equipments for Sale ijnek Malaysian R/C Racers 22836 09-09-2009 01:50 PM
R/C Stuff Selling Kenneth Tan Singapore R/C Racers 45728 09-09-2009 07:19 AM
FOR SALE - all for sale posts here Sil80 Australian Racing 10483 12-29-2005 03:37 PM



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 06:06 AM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net