Author Topic: '86 TRX250R Rebuild (Read 16692 times)

Turftamer · « **on:** November 22, 2013, 09:32:10 PM »

I picked this quad up about 2 years ago. It was very clean and ran pretty good. There were a few small issues. The drain plug threads were cracked and required silicone to be cleaned out and re-applied every oil change. The case saver mounts were damaged, but functional. Compression was OK but not great and there were also a few cracks in the frame. The previous owner cracked the original swingarm and bent the shock. His son had a 2006 TRX450R he was upgrading the suspension on, so he decided to try the 450R swingarm conversion with the stock take off parts. I actually think handled rather well compared to my limited experience. The only problem was, in order to get the sprockets to line up, he had to shift the engine over to the right 3/4". This created a bunch of fitment issues with the carb and exhaust. He also had to modify the linkage mount, rear motor mount, lower motor mounts and headstay (which eventually broke in half). I think this was the cause of the majority of the frame cracks. I rode it for about a year like this before I decided to do a complete rebuild.

Turftamer · « **Reply #1 on:** November 22, 2013, 09:43:40 PM »

I decided to completely strip the bike down and either fix or replace any problems I could find. I relocated the engine mounts to the stock positions, repaired all the cracks and added Pumashines gusset kit. I wanted to put an aftermarket swingarm back on to fix the alignment issues and retain the handling, but since the linkage mounts had been heavily modified, I decided I would have to either re-use the 450R swingarm or replace the frame. My wallet actually made the choice for me.

I sent the frame and several major components out for powdercoating.

Turftamer · « **Reply #2 on:** November 22, 2013, 09:55:17 PM »

I tore down the engine and sent the cylinder to Neil for porting, boring, and fitting of a new piston. While the cylinder was away I had the cases repaired and powder coated by BDT. I found a few tranny gears that had some wear, but luckily I had some spares.

When everything came back I started sanding and polishing everything, mostly by hand.

Turftamer · « **Reply #3 on:** November 22, 2013, 10:08:38 PM »

Here's how the swingarm linkage mounts were modified. I thought about trying to cut it out to use a 250R swinger but figured it just wasn't worth the effort.

Upper shock mount adapter bracket.

For some reason I had to grind down the swingarm to fit between the frame again. Maybe thickness of the PC added to some distortion from the welding created an issue.

Turftamer · « **Reply #4 on:** November 22, 2013, 10:13:47 PM »

Motors back together and in the frame.

Rear shock and linkage installed.

Turftamer · « **Reply #5 on:** November 22, 2013, 10:23:15 PM »

In order to relocate the engine back to the stock position and remedy the sprocket alignment issue, I had the rear sprocket hub machined and a spacer made to take up the space on the other side.

New chain, Pumashine case saver, and PC sprocket cover.

I removed the blue anodizing from the Nacs kicker with the intentions of polishing it.

Vacuum testing cylinder.

More pics to come!

jamieg45 · « **Reply #6 on:** November 22, 2013, 11:22:38 PM »

Nice build man, and your polish work looks great man as well. I lime your attention to detail and your eye for shiny parts. Keep up the great work man.

Pumashine · « **Reply #7 on:** November 23, 2013, 01:07:04 AM »

Your build is looking pretty sweet. I can tell you have been working your fingers to the bone. Doing a stock cylinder by hand has got to very time consuming. I got tired after my first one. Keep at it and it will definitely be a show quality bike.

Turftamer · « **Reply #8 on:** November 23, 2013, 11:18:53 AM »

Thanks guys. As soon as I started sanding on the cylinder I thought "This was a HUGE mistake", but I'm very happy how it turned out.

05450r · « **Reply #9 on:** November 23, 2013, 11:34:43 AM »

Very cool build, I like the 450r rear end!!

Turftamer · « **Reply #10 on:** November 30, 2013, 04:53:42 PM »

I picked up a CT midrange pipe due to recommendation from Neil to compliment the porting. Well, it didn't fit quite right with my Pro Circuit silencer.

After a little heating and bending and cutting and grinding, I finally got everything to fit together a little better.

Pumashine · « **Reply #11 on:** November 30, 2013, 05:11:48 PM »

Looks like your silencer mod worked pretty good. Its good to know I am not the only one with those kinds of problems.

Turftamer · « **Reply #12 on:** November 30, 2013, 05:45:45 PM »

Quote from: Pumashine;18788

Looks like your silencer mod worked pretty good. Its good to know I am not the only one with those kinds of problems.

I actually had to cut and bend the pipe to fit, the silencer I left alone. I had to shorten the stinger by about .700" and open up the bend a little. Now I just need some hangers

.

jamieg45 · « **Reply #13 on:** December 01, 2013, 12:30:09 AM »

Quote from: Turftamer;18787

I pickpCT midrange pipe duen o recommendation from Neil to compliment the porting. Well, it didn't fit quite right with my Pro Circuit silencer.

After a little heating and bending and cutting and grinding, I fiannaly got everything to fit together a little better.

[/QUnOTE]
Is that a Lrd black silencer laying on the floor in the last pic.

Turftamer · « **Reply #14 on:** December 01, 2013, 01:31:38 AM »

[/QUOTE]Is that a Lrd black silencer laying on the floor in the last pic.[/QUOTE]

Nah, it's the same red one that came with the bike.

I was using for mock up.