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Author Topic: 1988 trx250r rear motor mount issue(please advise)  (Read 608 times)

Offline ingeniusone7

1988 trx250r rear motor mount issue(please advise)
« on: December 17, 2018, 12:39:07 AM »
So I noticied yesterday that a my cool head does not have a bolt ear on it to mount my upper motor mount to it. I also noticied that my lower back motor mount hole is empty. SO I need help not only understanding this but how to fix and get to riding. I have already read that the swingarms are different on the 86-88 frames where they incorporate the motor mount bracket for the rear into the earlier swingarms. What I am trying to figure out is did the 1988 tr250r from the factory not come with a lower rear motor mount bolted to the frame. Because I thought all the cases were the same regardless of internal changes through the different years. As far as I know my 88 tr250r has the original motor and frame. I keep reading that everyone welds a bracket to hold the lower motor mount hole. But why the heck should I have to weld anything. didnt honda engineer machine to begin with. Just confused and dont want to weld anything just want to run like it was made to begine with. SO please someone advise me on how to fix my problem as its crazy to me that I have to weld a bracket on or change my swingarm out for a older swingarm with the bracket. their should be another way??

Offline hickwheeler

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #1 on: December 17, 2018, 01:30:59 AM »
88 frames did not come with a lower rear motor mount. It is fine with out it. You will probably want to find a head stay on eBay or ask to see if someone here has one they'd sell you. I hope this helps you
88 ESR 330 5mil stroke
88 ct350pv (BOF Build)
Puma coming soon

Offline hickwheeler

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #2 on: December 17, 2018, 01:33:21 AM »
Sorry tread your post. Need different cool-headed or get a stock head to fix upper mount. You could probably make a bracket that bolts to the head. Then get it to mount to head stay
88 ESR 330 5mil stroke
88 ct350pv (BOF Build)
Puma coming soon

Offline F-Red

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #3 on: December 17, 2018, 07:05:32 AM »
Gene is correct, no mount on the 88 frame. Your good, no further action needed. As far as the top head mount, some donít use the bolt through the head. Too rigid. I bolt the bracket to the frame for support. Eliminating the bolt through the head.
Want To See My Wieners?

Offline croat1

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #4 on: December 17, 2018, 07:56:12 AM »
1985-86 ATC and 86-87 TRX use a "H" bracket for the year mount.  88-89 TRX use a rear top cross member mount .  I've seen guys weld in lower rear engine mounting tabs for the 88/89 frames.  I'd guess added insurance. 

on the head stay...I agree with Gene and Fred.  use it to tie in the upper frame rails. bolting it to the head....a matter of opinion.   

cases:  85/86 ATC and 86-89 are all pretty much the same (minor difference in the front of the engine)....cosmetic

As to why Honda did things the way they did...they sure hit it out of the park with the greatest quad of all time in a 4 year production run.  oem engines and chassis' still smokin'.  gotta love it

Joe

Offline 2Nubs

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #5 on: December 17, 2018, 09:56:14 AM »
Had these questions when I went from my 88 frame to an 86 and these same gentlemen helped me out. Looks like it was thoroughly answered here.

FWIW, the bolt through the head is highly debatable, but I do not use one and have had zero bad side effects from it. Some say that it does not allow the cylinder/head to expand and can cause head gasket issues. Most that DO use the bolt through the head agree that you should not torque it down very tight.

I believe most everyone agrees that the head stay bracket should be bolted to the frame, regardless of using the head bolt, as it adds needed rigidity.
Ď86 330

Offline broken1

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #6 on: December 17, 2018, 11:06:39 AM »
The most important thing with all the engine mounting bolts (regardless if you run a head stay bolt or not) is to check them periodically & make sure they stay torqued.
overkill is an often underrated achievement

Offline ingeniusone7

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #7 on: December 19, 2018, 02:01:03 AM »
88 frames did not come with a lower rear motor mount. It is fine with out it. You will probably want to find a head stay on eBay or ask to see if someone here has one they'd sell you. I hope this helps you

thanks for reply. I found out that the rear mount is not a issue. I was just worried. As far as the head stay goes. I hear mixed reviews. some say not to run it..others say to run it..Pros vs Cons? thanks

Offline ingeniusone7

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #8 on: December 19, 2018, 02:04:00 AM »
Gene is correct, no mount on the 88 frame. Your good, no further action needed. As far as the top head mount, some donít use the bolt through the head. Too rigid. I bolt the bracket to the frame for support. Eliminating the bolt through the head.


Ask you the same question pros vs cons on the upper head stay. Im currently running the brace through the frame for the head stay, just not mount on my cool head to mount with a bolt to the frame brace   Pros vs Cons? on bolting up the head stay? Or just leave it

Offline ingeniusone7

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #9 on: December 19, 2018, 02:05:54 AM »
1985-86 ATC and 86-87 TRX use a "H" bracket for the year mount.  88-89 TRX use a rear top cross member mount .  I've seen guys weld in lower rear engine mounting tabs for the 88/89 frames.  I'd guess added insurance. 

on the head stay...I agree with Gene and Fred.  use it to tie in the upper frame rails. bolting it to the head....a matter of opinion.   

cases:  85/86 ATC and 86-89 are all pretty much the same (minor difference in the front of the engine)....cosmetic

As to why Honda did things the way they did...they sure hit it out of the park with the greatest quad of all time in a 4 year production run.  oem engines and chassis' still smokin'.  gotta love it

Joe

Yes I love my 250r, amazing machine. Pros vs cons on head stay?

Offline F-Red

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #10 on: December 19, 2018, 07:27:10 AM »
Gene is correct, no mount on the 88 frame. Your good, no further action needed. As far as the top head mount, some donít use the bolt through the head. Too rigid. I bolt the bracket to the frame for support. Eliminating the bolt through the head.


Ask you the same question pros vs cons on the upper head stay. Im currently running the brace through the frame for the head stay, just not mount on my cool head to mount with a bolt to the frame brace   Pros vs Cons? on bolting up the head stay? Or just leave it

In my opinion, there are no proís to using the bolt on the head. The engine has adequate mounts. The conís have been stated. You mentioned some use the bolt. Please tell us, why they use it.
Want To See My Wieners?

Online jcs003

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #11 on: December 19, 2018, 08:59:51 AM »
I would use the head stay.  there is a reason Honda kept it even after they changed the rear mount.

also, unless someone has some FEA showing the head stay bracket is not a stress member, than i would keep using it.

Offline 2Nubs

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #12 on: December 19, 2018, 09:19:56 AM »
I wouldn't call factory engineering a reason to keep something the same necessarily lol, but I've only read of head gasket problems. Never seen one personally.

I can say that I do not use one and it does not cause any problems. 

To the OP, you can google this question and read about it for days if you want.
Ď86 330

Offline broken1

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #13 on: December 19, 2018, 11:38:19 AM »
I've had my R for 30 years & have never run it without the head stay bolted to the head. The most important thing is checking torque on the engine mounting bolts regularly regardless if you decide to bolt the head to the head stay or not.

overkill is an often underrated achievement

Online jcs003

Re: 1988 trx250r rear motor mount issue(please advise)
« Reply #14 on: December 20, 2018, 09:35:20 AM »
i have heard claims it will rev free'er, but that is probably negligible.

i wonder how may frame crack propagate from not using the head stay???  ponder that.haha